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Nausea and Vomiting (PDQ®): Supportive care - Health Professional Information [NCI]Purpose of This PDQ SummaryThis PDQ cancer information summary provides comprehensive, peer-reviewed information for health professionals about the pathophysiology and treatment of nausea and vomiting. This summary is reviewed regularly and updated as necessary by the PDQ Supportive and Palliative Care Editorial Board. Information about the following is included in this summary:
This summary is intended as a resource to inform and assist clinicians and other health professionals who care for cancer patients during and after cancer treatment. It does not provide formal guidelines or recommendations for making health care decisions. Information in this summary should not be used as a basis for reimbursement determinations. This summary is also available in a patient version, which is written in less technical language, and in Spanish. OverviewPrevention and control of nausea and vomiting are paramount in the treatment of cancer patients. Nausea and vomiting can result in serious metabolic derangements, nutritional depletion and anorexia, deterioration of patients' physical and mental status, esophageal tears, fractures, wound dehiscence, withdrawal from potentially useful and curative antineoplastic treatment, and degeneration of self-care and functional ability. Despite advances in pharmacologic and nonpharmacologic management, nausea and vomiting remain two of the more distressing and feared side effects to cancer patients and their families, and incidence may be underestimated by physicians and nurses.[1,2,3,4,5] Introduction Nausea is a subjective phenomenon of an unpleasant, wavelike sensation experienced in the back of the throat and/or the epigastrium that may or may not culminate in vomiting. Vomiting is the forceful expulsion of the contents of the stomach, duodenum, or jejunum through the oral cavity. Retching is gastric and esophageal movements of vomiting without expulsion of vomitus and is also referred to as dry heaves. Classifications Various classifications of nausea and vomiting (N&V) have been used,[1,6] including acute, delayed, late or persistent, chronic, anticipatory, breakthrough, or refractory, as well as distinctions related to type of treatment (e.g., chemotherapy- or radiation-induced), and clinical course (e.g., advanced or terminal disease).[7,8] Despite this variety, the most commonly described types are acute, delayed, and anticipatory chemotherapy-induced N&V; and chronic N&V in advanced cancer patients. Although there are no standard definitions, the following are commonly used to classify the different types.
Table 1. Criteria for Grading Severity of Nausea and Vomiting*
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NeurophysiologyProgress has been made in understanding the neurophysiologic mechanisms that control nausea and vomiting. Both are controlled or mediated by the central nervous system but by different mechanisms. Nausea is mediated through the autonomic nervous system. Vomiting results from the stimulation of a complex reflex that is coordinated by a putative true vomiting center, which may be located in the dorsolateral reticular formation near the medullary respiratory centers. The vomiting center presumably receives convergent afferent stimulation from several central neurologic pathways, including the following:[1,2]
The CTZ is located in the area postrema, one of the circumventricular regions of the brain on the dorsal surface of the medulla oblongata at the caudal end of the fourth ventricle. Unlike vasculature within the blood-brain diffusion barrier, the area postrema is highly vascularized with fenestrated blood vessels, which lack tight junctions (zonae occludentes) between capillary endothelial cells. The CTZ is anatomically specialized to readily sample elements present in the circulating blood and cerebrospinal fluid (CSF).[3,4] Currently, evidence indicates that acute emesis following chemotherapy is initiated by the release of neurotransmitters from cells that are susceptible to the presence of toxic substances in the blood or CSF. Area postrema cells in the CTZ and enterochromaffin cells within the intestinal mucosa are implicated in initiating and propagating afferent stimuli that ultimately converge on central structures corresponding to a vomiting center. The relative contribution from these multiple pathways culminating in nausea and vomiting symptoms is complex and is postulated to account for the variable emetogenicity (intrinsic emetogenicity and mitigating factors, i.e., dosage, administration route, exposure duration) and emetogenic profile (i.e., time to onset, symptom severity, and duration) of agents. References:
General Risk Factors and EtiologiesNot all cancer patients will experience nausea and/or vomiting. The most common causes are emetogenic chemotherapy drugs and radiation therapy to the gastrointestinal (GI) tract, liver, or brain. Several patient characteristics have also been identified. These include incidence and severity of nausea and vomiting (N&V) during past courses of chemotherapy, history of chronic alcohol use, age, and gender. Patients with poor control of N&V during prior chemotherapy cycles are likely to experience N&V in subsequent cycles. N&V is less likely in patients with a history of chronic, high alcohol intake,[1] and more likely in women [2,3] and younger patients (<50 years).[2] Other possible causes include fluid and electrolyte imbalances such as hypercalcemia, volume depletion, or water intoxication; tumor invasion or growth in the GI tract, liver, or central nervous system, especially the posterior fossa; constipation; certain drugs such as opioids; infection or septicemia; or uremia. The psychological variables of state anxiety (level of anxiety during chemotherapy infusions), and pretreatment expectations for nausea and vomiting (self-fulfilling prophecy) have also been investigated as predictors of posttreatment nausea.[4,5,6,7,8,9] At present, studies have found mixed results that vary due to different research methods. Better designed studies, however, have found state anxiety and patient expectations for nausea to be predictors of posttreatment nausea, even after controlling for known physiological predictors (susceptibility to nausea during pregnancy and motion sickness) and emetogenic potential of the chemotherapy drugs.[6,7,8,10,11] It is important to note, however, that patients' fears and expectations about chemotherapy can be variable and change over time.[12] In a longitudinal study [12] patients' anticipatory fears of vomiting decreased significantly from pretreatment to a period 3 to 6 months later, particularly when their chemotherapy included antiemetic medications. Clinicians treating N&V must be alert to all potential causes and factors, especially in cancer patients who may be receiving combinations of several treatments and medications. (Refer to the PDQ summary on Pain for more information on opioid-induced nausea and vomiting.) References:
Anticipatory Nausea and VomitingPrevalence The prevalence of anticipatory nausea and vomiting (ANV) has varied, owing to changing definitions and assessment methods.[1] However, anticipatory nausea (AN) appears to occur in approximately 29% of patients receiving chemotherapy, or about 1:3, while anticipatory vomiting (AV) appears to occur in 11% of patients, or about 1:10.[2] With the introduction of new pharmacologic agents (5-HT3 receptor antagonists), it was anticipated that the prevalence of ANV might decline; however, studies have shown mixed results. One study found a lower incidence of ANV,[3] and three studies found comparable incidence rates.[2,4,5] It appears that the 5-HT3 agents reduce postchemotherapy vomiting, but not postchemotherapy nausea,[2,5] and the resulting impact on ANV is unclear. Classical Conditioning Although other theoretical mechanisms have been proposed,[6] ANV appears to be best explained by classical conditioning (also known as Pavlovian or respondent conditioning).[7] In classical conditioning, a previously neutral stimulus (e.g., smells of the chemotherapy environment) elicits a conditioned response (e.g., ANV) after a number of prior pairings or learning trials. In cancer chemotherapy the first few chemotherapy infusions are the learning trials. The chemotherapy drugs are the unconditioned stimuli that elicit postchemotherapy nausea and vomiting (in some patients). They are paired with a variety of other neutral, environmental stimuli (e.g., smells of the setting, oncology nurse, chemotherapy room). These previously neutral stimuli then become conditioned stimuli and elicit ANV in future chemotherapy cycles. ANV is not an indication of psychopathology, but rather a learned response that, in other life situations (e.g., food poisoning) results in adaptive avoidance. A variety of correlational studies provide empirical support for classical conditioning. For example, the prevalence of ANV prior to any chemotherapy is very rare, and few patients ever experience ANV without prior postchemotherapy nausea.[8] Also, most studies have found a higher probability of ANV with increasing numbers of chemotherapy infusions, and the intensity of ANV increases as patients get closer to the actual time of their infusion.[9] In one experimental study, it was shown that a novel beverage could become a conditioned stimulus to nausea when paired with several chemotherapy treatments.[10] Variables Correlated with ANV Many variables have been investigated as potential factors that correlate with the incidence of ANV in hopes of developing a list of risk factors. There is currently no agreement on which factors predict ANV. A patient with fewer than three of the first eight characteristics listed below, however, is unlikely to develop ANV, and screening following the first chemotherapy infusion could identify those patients at increased risk.[11] Variables Found to Correlate With ANV
Treatment of ANV Antiemetic drugs do not seem to control ANV once it has developed;[2] however, a variety of behavioral interventions have been investigated.[19] These include progressive muscle relaxation with guided imagery,[20] hypnosis,[21] systematic desensitization,[22] electromyography (EMG) and thermal biofeedback,[23] and distraction via the use of video games.[24,25] Progressive muscle relaxation with guided imagery, hypnosis, and systematic desensitization has been studied the most and is the recommended treatment. Referral to a psychologist or other mental health professional with specific training and experience in working with cancer patients is recommended when ANV is identified. The earlier it is identified, the more likely treatment will be effective, and thus early screening and referral are essential. In addition, physicians and nurses underestimate the incidence of chemotherapy-induced nausea and vomiting.[26] References:
Acute / Delayed Emesis EtiologyAcute Emesis
In addition to emetogenic potential, the dose and schedule used are also extremely important factors. For example, a drug with a low emetogenic potential given in high doses may cause a dramatic increase in the potential to induce nausea and vomiting. Standard doses of cytarabine rarely produce nausea and vomiting, but these are often seen with high doses of this drug. Another factor to consider is the use of drug combinations. Because most patients receive combination chemotherapy, the emetogenic potential of all of the drugs combined and individual drug doses needs to be considered. Delayed Emesis Delayed (or late) nausea and vomiting (emesis): Nausea and vomiting that occurs more than 24 hours after chemotherapy administration is considered delayed or late nausea and vomiting. Delayed nausea and vomiting is associated with cisplatin, cyclophosphamide, and other drugs (e.g., doxorubicin and ifosfamide) given at high doses or on 2 or more consecutive days.
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Prevention of Acute / Delayed EmesisAntiemetic agents are the most common intervention in the management of treatment-related nausea and vomiting. The basis for antiemetic therapy is the neurochemical control of vomiting. Although the exact mechanism is not well understood, peripheral neuroreceptors and the chemoreceptor trigger zone (CTZ) are known to contain receptors for serotonin, histamine (H1 and H2), dopamine, acetylcholine, opioids, and numerous other endogenous neurotransmitters.[1,2] Many antiemetics act by competitively blocking receptors for these substances, thereby inhibiting stimulation of peripheral nerves at the CTZ, and perhaps at the vomiting center. Most drugs with proven antiemetic activity can be categorized into one of the following groups:
Although all routes of administration are listed for each of the following drugs, the intramuscular (IM) route should be used only when no other access is available. Intramuscular delivery is painful, is associated with erratic absorption of drug, and may lead to sterile abscess formation or fibrosis of the tissues. This is particularly important when more than 1 or 2 doses of a drug are to be given. Phenothiazines Phenothiazines act on dopaminergic receptors at the CTZ, and perhaps at other central nervous system (CNS) centers, and peripherally. With the exception of thioridazine, many phenothiazines possess antiemetic activity, including chlorpromazine given in the 10- to 50-mg dose range orally, IM, intravenously (IV), and rectally (pediatric dose for older than 12 years: 10 mg every 6-8 hours; for younger than 12 years: 5 mg every 6-8 hours); thiethylperazine given in the 5- to 10-mg dose range orally, IM, and IV; and perphenazine. The primary consideration in selecting among phenothiazines are differences in their adverse effect profiles, which substantially correlate with their structural classes. Generally, aliphatic phenothiazines (e.g., chlorpromazine, methotrimeprazine) produce sedation and anticholinergic effects, while piperazines (e.g., prochlorperazine, thiethylperazine, perphenazine, and fluphenazine) are associated with less sedation but greater incidence of extrapyramidal reactions (EPRs). Prochlorperazine This drug is perhaps the most frequently (and empirically) used antiemetic and, in low doses, is generally effective in preventing nausea associated with radiation therapy and in treating nausea and vomiting attributed to very low to moderately emetogenic chemotherapeutic drugs. It is a phenothiazine and can be given orally, IM, IV, and rectally. It is usually given in the 10- to 50-mg dose range (pediatric dose for children who weigh more than 10 kg or who are older than 2 years: orally or rectally, 0.4 mg/kg/d tid-qid; or IM, 0.1-0.15 mg/kg/dose tid-qid, maximum 40 mg/d). Higher prochlorperazine doses (e.g., 0.2-0.6 mg/kg/dose) are also used IV for chemotherapy with high emetogenic potential.[3,4] Phenothiazines may be of particular value in treating patients who experience delayed nausea and vomiting (postacute phase symptoms) on cisplatin regimens.[5] As with other dopaminergic antagonists, the most common side effects of prochlorperazine are EPRs (acute dystonias, akathisias, neuroleptic malignant syndrome [uncommon], and rarely, akinesias and dyskinesias), and sedation. Marked hypotension may also result if IV prochlorperazine is administered rapidly at high doses. Administration over at least 30 minutes appears adequate to prevent hypotensive episodes.[6,7,8] Butyrophenones Droperidol and haloperidol These two drugs represent another class of dopaminergic (D2 subtype) receptor antagonists that are structurally and pharmacologically similar to the phenothiazines. While droperidol is used primarily as an adjunct to anesthesia induction, haloperidol is indicated as a neuroleptic antipsychotic drug; however, both agents have potent antiemetic activity. Droperidol is administered IM or IV, typically from 1 to 2.5 mg every 2 to 6 hours, but higher doses (up to 10 mg) have been safely given.[9,10] Haloperidol is administered IM, IV, or orally, typically from 1 to 4 mg every 2 to 6 hours.[11] Both agents may produce EPRs, akathisia, hypotension, and sedation. Dopamine 2 Antagonists Metoclopramide Metoclopramide is a substituted benzamide, which, prior to the introduction of serotonin (5-HT3) receptor antagonists, was considered the most effective single antiemetic agent against highly emetogenic chemotherapy such as cisplatin. Although metoclopramide is a competitive antagonist at dopaminergic (D2) receptors, it is most effective against acute vomiting when given IV at high doses (e.g., 0.5-3 mg/kg/dose), probably because it is a weak competitive antagonist (relative to other serotonin antagonists) at 5-HT3 receptors. It may act on the CTZ and the periphery. Metoclopramide also increases lower esophageal sphincter pressure and enhances the rate of gastric emptying, which may factor into its overall antiemetic effect. It can be administered IV at the U.S. Food and Drug Administration (FDA)-approved dose of 1 to 2 mg/kg every 2 hours (or less frequently) for 3 to 5 doses. Metoclopramide has also been safely given by IV bolus injection at higher single doses (up to 6 mg/kg) and by continuous IV infusion, with or without a loading bolus dose, with efficacy comparable to multiple intermittent dosing schedules.[12,13,14] Metoclopramide is associated with akathisia and dystonic extrapyramidal effects, with the latter seen more commonly in persons younger than 30 years, and the former seen more frequently in patients older than 30 years. Diphenhydramine, benztropine mesylate, and trihexyphenidyl are commonly used prophylactically or therapeutically to pharmacologically antagonize EPRs.[6,15] While cogwheeling rigidity, acute dystonia, and tremor are responsive to anticholinergic medications, akathisia, the subjective sense of restlessness or inability to sit still, is best treated by (1) switching to a lower potency neuroleptic for emesis, if possible; (2) lowering the dose; or (3) adding a benzodiazepine (i.e., lorazepam) or beta blocker (i.e., propranolol). 5-HT3 Antagonists Four serotonin receptor antagonists—ondansetron, granisetron, dolasetron, and palonosetron—are available in the United States. Tropisetron, while not approved by the FDA, is available internationally. Agents in this class are thought to prevent nausea and vomiting by preventing serotonin, which is released from enterochromaffin cells in the gastrointestinal (GI) mucosa, from initiating afferent transmission to the CNS via vagal and spinal sympathetic nerves.[16] The 5-HT3 antagonists may also block serotonin stimulation at the CTZ and other CNS structures. Ondansetron Several studies have demonstrated that ondansetron produces an antiemetic response that equals or is superior to high doses of metoclopramide, but ondansetron has a superior toxicity profile compared with dopaminergic antagonist agents.[17,18,19,20,21,22,23] Ondansetron (0.15 mg/kg) is given IV 15 to 30 minutes prior to chemotherapy and is repeated every 4 hours for two additional doses. Alternatively, for patients older than 18 years, a large multicenter study determined that a single 32-mg dose of ondansetron is more effective in treating cisplatin-induced nausea and vomiting than a single 8-mg dose, and is as effective as the standard regimen of three doses at 0.15 mg/kg given every 4 hours starting 30 minutes before chemotherapy.[24] A single-center retrospective chart review has reported ondansetron-loading doses of 16 mg/m² (maximum, 24 mg) IV to be safe in infants, children, and adolescents.[25] Currently, the oral and injectable ondansetron formulations are approved for use without dosage modification in patients older than 4 years, including the elderly and patients with renal insufficiency. Oral ondansetron is given 3 times daily starting 30 minutes before chemotherapy and continuing for up to 2 days after chemotherapy is completed. Patients older than 12 years should receive 4 mg per dose. Ondansetron is not approved for use in children younger than 4 years. Ondansetron clearance is diminished in patients with severe hepatic insufficiency; therefore, such patients should receive a single injectable or oral dose no greater than 8 mg. There is currently no information available evaluating the safety of repeated daily ondansetron doses in patients with hepatic insufficiency. Other effective dosing schedules, such as a continuous IV infusion (e.g., 1 mg/hr for 24 hours) or oral administration have also been evaluated.[24] The major adverse effects include headache (which can be treated with mild analgesics), constipation or diarrhea, fatigue, dry mouth, and transient asymptomatic elevations in liver function tests (alanine [ALT] and aspartate [AST] transaminases), which may be related to concurrent cisplatin administration.[26] Ondansetron has been etiologically implicated in a few case studies involving thrombocytopenia, renal insufficiency, and thrombotic events.[27] In addition, a few case reports have implicated ondansetron in causing EPRs. However, it is not clear in some cases whether the events described were in fact EPRs, and in other reports the evidence is confounded by concurrent use of other agents that are known to produce EPRs. Nevertheless, the greatest advantage of serotonin receptor antagonists over dopaminergic receptor antagonists is that they have fewer adverse effects. Despite prophylaxis with ondansetron, many patients receiving doxorubicin, cisplatin, or carboplatin will experience acute and delayed-phase nausea and vomiting.[28] A randomized, double-blind, placebo-controlled trial suggests that the addition of aprepitant, a neurokinin-1 (NK1) antagonist, may mitigate nausea and vomiting.[29] The optimal dose of aprepitant may be 125 mg on day 1 followed by 80 mg on days 2 to 5.[30] Granisetron Granisetron has demonstrated efficacy in preventing and controlling nausea and vomiting at a broad range of doses (e.g., 10-80 µg/kg and empirically, 3 mg per dose). In the United States, granisetron injection and oral tablets are approved for initial and repeat prophylaxis for patients receiving emetogenic chemotherapy, including high-dose cisplatin. Granisetron is pharmacologically and pharmacokinetically distinct from ondansetron; however, clinically it appears equally efficacious and equally safe.[31,32,33] Both granisetron formulations are given before chemotherapy, as either a single IV dose of 10 µg/kg (0.01 mg/kg) or 1 mg orally every 12 hours. Both granisetron formulations and ondansetron injection share the same indication against highly emetogenic chemotherapy. In contrast, the oral ondansetron formulation has been approved only for use against nausea and vomiting associated with moderately emetogenic chemotherapy. Currently, granisetron injection is approved for use without dosage modification in patients older than 2 years, including the elderly and patients with hepatic and renal insufficiency. Oral granisetron has not yet been approved for use in pediatric patients. Dolasetron Both oral and injection formulations are indicated for the prevention of nausea and vomiting associated with moderately emetogenic cancer chemotherapy including initial and repeat courses. Oral dolasetron should be dosed as 100 mg within 1 hour before chemotherapy. Dolasetron should be given IV or orally at 1.8 mg/kg as a single dose approximately 30 minutes before chemotherapy. The effectiveness of oral dolasetron in the prevention of chemotherapy-induced nausea and vomiting has been proven in a large randomized, double-blind, comparative trial of 399 patients.[34] Oral dolasetron was administered in the range of 25 to 200 mg 1 hour prior to chemotherapy. The other study arm consisted of oral ondansetron (8 mg) administered 1.5 hours before chemotherapy and every 8 hours after, for a total of 3 doses. Complete response (CR) rates improved with increasing doses of dolasetron. Both dolasetron 200 mg and ondansetron had significantly higher CR rates as compared with dolasetron 25 mg or 50 mg. (CR was defined as no emetic episodes and no use of escape antiemetic medications.) Dolasetron injection has also been proven effective in the prevention of chemotherapy-induced nausea and vomiting.[35] Palonosetron Palonosetron is a new 5-HT3 receptor antagonist (second generation) that has antiemetic activity at both central and gastrointestinal sites. In comparison to the older 5-HT3 receptor antagonists, it has a higher binding affinity to the 5-HT3 receptors, a higher potency, a significantly longer half-life (approximately 40 hours, four to five times longer than that of dolasetron, granisetron, or ondansetron), and an excellent safety profile.[36] A dose-finding study demonstrated that the effective dose was 0.25 mg or higher.[36] In two large studies of patients receiving moderately emetogenic chemotherapy, CR (no emesis, no rescue) was significantly improved in the acute and the delayed period for patients who received 0.25 mg of palonosetron alone compared with either ondansetron or dolasetron alone.[37,38] Dexamethasone was not given with the 5-HT3 receptor antagonists in these studies, and it is not yet known whether the differences in CR would persist if dexamethasone was used. In another study,[39] 650 patients receiving highly emetogenic chemotherapy (cisplatin =60 mg/m2) also received either dexamethasone and one of two doses of palonosetron (0.25 mg or 0.75 mg) or dexamethasone and ondansetron (32 mg). Single-dose palonosetron was as effective as ondansetron in preventing acute chemotherapy-induced nausea and vomiting with dexamethasone pretreatment; it was significantly more effective than ondansetron throughout the 5-day postchemotherapy period. In an analysis of the patients in the above studies who received repeated cycles of chemotherapy, one author [40] reported that the CR rates for both acute and delayed chemotherapy-induced nausea and vomiting were maintained with single IV doses of palonosetron without concomitant corticosteroids. These data have been presented in abstract form only and will require further review. Based on the above studies, palonosetron was approved by the FDA in July 2003 for the prevention of acute nausea and vomiting associated with initial and repeat courses of moderately and highly emetogenic cancer chemotherapy; and for the prevention of delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy. Comparison of agents Clinicians should note that studies suggest that there are no major differences in efficacy or toxicity of the three first-generation 5-HT3 receptor antagonists (dolasetron, granisetron, ondansetron) in the treatment of chemotherapy-induced acute nausea and vomiting. These three agents are equivalent in efficacy and toxicity when used in appropriate doses.[41,42,43,44] Although these agents have been shown to be effective in the first 24 hours postchemotherapy (acute phase), they have not been demonstrated to be effective in days 2 to 5 postchemotherapy (delayed phase).[45,46,28] Palonosetron, the second-generation 5-HT3 receptor antagonist, has been approved for the control of delayed emesis for patients receiving moderately emetogenic chemotherapy.[37,38] Despite the use of both first-generation and second-generation 5-HT3 receptor antagonists, the control of acute chemotherapy-induced nausea and vomiting, and especially delayed nausea and vomiting, is suboptimal and there is considerable opportunity for improvement with either the addition or substitution of new agents in current regimens.[45,46,28,47] Substance P Antagonists (NK-1 Receptor Antagonists) The initial clinical studies using the NK-1 receptor antagonists [48,49,50,51] demonstrated that the addition of an NK-1 receptor antagonist (CP-122,721, CJ-11,794, MK-0869 [aprepitant]) to a 5-HT3 receptor antagonist plus dexamethasone prior to cisplatin chemotherapy improved the control of acute emesis compared to 5-HT3 plus dexamethasone, and improved the control of delayed emesis compared with placebo. In addition, as a single agent, MK-0869 (aprepitant) had a similar effect on cisplatin-induced acute emesis as ondansetron but was superior in the control of delayed emesis. Subsequent studies [52,53] showed that the combination of aprepitant and dexamethasone was similar to a 5-HT3 receptor antagonist plus dexamethasone in controlling acute emesis but was inferior in controlling acute emesis compared with triple therapy (aprepitant, 5-HT3 receptor antagonist, and dexamethasone). These studies also confirmed the improvement of delayed emesis with the use of aprepitant compared with placebo. Two studies [30,54] have also shown an improvement in cisplatin-induced delayed emesis with the combination of aprepitant and dexamethasone compared with dexamethasone alone, with the improvement maintained over repeat cycles of cisplatin chemotherapy. In two randomized, double-blind, parallel, multicenter, controlled studies (520 patients in each study), patients received cisplatin (=70 mg/m2) and were randomized to receive either standard therapy of a 5-HT3 receptor antagonist (ondansetron) and dexamethasone prechemotherapy and dexamethasone postchemotherapy (days 2-4) or standard therapy plus aprepitant prechemotherapy and on days 2 and 3 postchemotherapy.[55,29] The CR (no emesis, no rescue) of the aprepitant group in both studies was significantly higher in both the acute period (83%-89%) and the delayed period (68%-75%), compared with the CR of the standard therapy group in the acute period (68%-78%) and delayed period (47%-56%). Nausea was improved in the aprepitant group for some, but not all of the various specific measures of nausea.[29] The studies discussed above formed the basis for the approval of aprepitant by the FDA in March 2003. In combination with other antiemetics, aprepitant is indicated for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy, including high-dose cisplatin. An additional study confirmed the efficacy of aprepitant in the delayed period, when it was compared with ondansetron.[56] All of the initial studies using aprepitant have been conducted in patients receiving highly emetogenic chemotherapy, such as cisplatin-based chemotherapy regimens. Subsequently, one group [57] presented a study on the use of aprepitant in 862 breast cancer patients receiving moderately emetogenic chemotherapy (i.e., cyclosphamide, doxorubicin). Two regimens were compared. Because the chemotherapy was moderately emetogenic, steroids were omitted from both arms, as illustrated in Table 2, Comparison of Aprepitant and Standard Regimens. Table 2. Comparison of Aprepitant and Standard Regimens
There was a significant improvement in complete response (no emesis, no rescue) in the 24 hours after chemotherapy in the patients receiving aprepitant; however, there was no significant improvement in complete response on days 2 to 5 in the postchemotherapy period when aprepitant alone was compared with ondansetron alone. The overall (days 1-5) complete response was significantly improved for the aprepitant-containing regimen, most likely because of the improvement in the first 24 hours. The control of nausea in moderately emetogenic chemotherapy was not improved with the use of aprepitant without steroids on days 2 and 3 postchemotherapy. The role of aprepitant in moderately emetogenic chemotherapy remains unclear. These results were consistent for multiple cycles of chemotherapy.[58] One open-label study demonstrated that in the 5 days postchemotherapy, aprepitant in combination with palonosetron and dexamethasone is safe and highly effective in preventing chemotherapy-induced nausea and vomiting in patients receiving moderately emetogenic chemotherapy.[59] Corticosteroids Steroids are sometimes used as single agents against mild to moderately emetogenic chemotherapy, but are more often used in antiemetic drug combinations.[60,61,62] Their antiemetic mechanism of action is not fully understood, but they may affect prostaglandin activity in the brain. Clinically, steroids quantitatively decrease or eliminate episodes of nausea and vomiting and may improve patients' mood, thus producing a subjective sense of well-being or euphoria (although they also can cause depression and anxiety). In combination with high-dose metoclopramide, steroids may mitigate adverse effects, such as the frequency of diarrheal episodes. Steroids are often given IV before chemotherapy and may or may not be repeated. Dosages and administration schedules are selected empirically. Dexamethasone is often the treatment of choice in treating nausea and vomiting in patients receiving radiation to the brain, as it also reduces cerebral edema. It is administered orally, IM, or IV in the dose range of 8 to 40 mg (pediatric dose: 0.25-0.5 mg/kg).[63,64,65,66,67] Methylprednisolone is also administered orally, IM, or IV at doses and schedules that vary from 40 to 500 mg every 6 to 12 hours for up to 20 doses.[62,68] Dexamethasone is also used orally for delayed nausea and vomiting. Long-term corticosteroid use, however, is inappropriate and may cause substantial morbidity, including immunosuppression, proximal muscle weakness (especially involving the thighs and upper arms), aseptic necrosis of the long bones, cataract formation, hyperglycemia and exacerbation of preexisting diabetes or escalation of subclinical diabetes to clinical pathology, adrenal suppression with hypocortisolism, lethargy, weight gain, GI irritation, insomnia, anxiety, mood changes, and psychosis. A study that examined chemotherapy in a group of patients with ovarian cancer found that short-term use of glucocorticoids as antiemetics had no negative effects on outcomes (i.e., overall survival, efficacy of chemotherapy).[69] As had previously been shown with metoclopramide, numerous studies have demonstrated that dexamethasone potentiates the antiemetic properties of 5-HT3 blocking agents.[70,71,72,73,74] If given IV, dexamethasone should be given over 10 to 15 minutes, since rapid administration may cause sensations of generalized warmth, pharyngeal tingling or burning, or acute transient perineal and/or rectal pain.[66,75,76,77] Prednisone and adrenocorticotropic hormone (ACTH) given concomitantly with other active antiemetic agents have also demonstrated efficacy against cisplatin-containing chemotherapy during the acute phase (within 24 hours after receiving chemotherapy).[78,79,80] In a double-blind randomized study of metoclopramide and dexamethasone with or without 1 mg of ACTH, patients receiving ACTH prophylaxis for cisplatin-containing chemotherapy experienced a significantly decreased incidence and severity of delayed emesis for up to 72 hours after treatment.[80] Cannabinoids Cannabinoids presumably target higher CNS structures to prevent nausea and vomiting.[81] Dronabinol (delta-9-tetrahydrocannabinol) is one of the psychoactive substances present in crude marijuana. Because of cultural and societal constraints and a low therapeutic index at clinically useful dosages, cannabinoids are often not among agents that are first selected for clinical use, but may be accepted and useful in selected patients.[82] Dronabinol is administered orally at 5 to 15 mg/m2, 1 to 3 hours before chemotherapy, then every 2 to 4 hours for up to 6 doses/day.[83,84,85] Adverse effects experienced along with the pharmacologic and psychogenic effects of cannabinoids include the following:
Dronabinol produces the following effects on the CNS at minimally effective dosages:[86,87,88,89]
Cardiovascular adverse effects typically manifest at dosages somewhat greater than those recommended for antiemetic effect and include tachycardia, vasodilation with variable effects on blood pressure, orthostatic symptoms, and decreased body temperature. With chronic administration, tolerance to cardiovascular and subjective effects may occur within days to weeks after treatment onset.[81] Benzodiazepines Benzodiazepines such as lorazepam, midazolam, and alprazolam, have become recognized as valuable adjuncts in the prevention and treatment of anxiety and anticipatory nausea and vomiting symptoms associated with chemotherapy, especially with the highly emetogenic regimens given to children.[90,91,92] Benzodiazepines have not demonstrated intrinsic antiemetic activity as single agents. Therefore, their place in antiemetic prophylaxis and treatment is adjunctive to other antiemetic agents.[93] Benzodiazepines presumably act on higher CNS structures, the brainstem, and spinal cord, and they produce anxiolytic, sedative, and anterograde amnesic effects. In addition, they markedly decrease the severity of EPRs, especially akathisia, associated with dopaminergic receptor antagonist antiemetics. Lorazepam Lorazepam may be administered orally, IM, IV, and sublingually. Dosages range from 0.5 to 3 mg (alternatively, 0.025-0.05 mg/kg, or 1.5 mg/m2, but =4 mg per dose) in adults and 0.03 to 0.05 mg/kg in children every 6 to 12 hours.[90,94,95,96] Midazolam produces mild-to-marked sedation for 1 to 4.5 hours at doses equal to 0.04 mg/kg given IV over 3 to 5 minutes.[97,98] Alprazolam has been shown to be effective when given in combination with metoclopramide and methylprednisolone.[99] The adverse effects of benzodiazepine include sedation, perceptual disturbances, disorders of micturition and/or defecation, visual disturbances, hypotension, anterograde amnesia, psychological dependence, confusion, ataxia, and depressed mental acuity with intoxication.[100] Olanzapine Olanzapine is an antipsychotic in the thienobenzodiazepine drug class that blocks multiple neurotransmitters: dopamine at D1, D2, D3, and D4 brain receptors; serotonin at 5-HT2a, 5-HT2c, 5-HT3, and 5-HT6 receptors; catecholamines at alpha-1 adrenergic receptors; acetylcholine at muscarinic receptors; and histamine at H1 receptors.[101] Common side effects are sedation and weight gain,[102,103] as well as an association with the onset of diabetes mellitus.[104] Olanzapine's activity at multiple receptors, particularly at the D2 and 5-HT3 receptors that appear to be involved in nausea and emesis, suggests that it may have significant antiemetic properties. There have been case reports on the use of olanzapine as an antiemetic.[105,106,107,108,109] These case reports prompted a phase I study in which olanzapine was used for the prevention of delayed emesis in cancer patients receiving their first cycle of chemotherapy consisting of cyclophosphamide, doxorubicin, cisplatin, and/or irinotecan.[110] The protocol was completed by 15 patients, and no grade 4 toxicities were seen. The maximum tolerated dose was 5 mg per day for 2 days prior to chemotherapy and 10 mg per day for 7 days postchemotherapy. Based on these data, olanzapine appeared to be a safe and effective agent for the prevention of delayed emesis in chemotherapy-naive cancer patients receiving cyclophosphamide, doxorubicin, cisplatin, and/or irinotecan. Using the maximum tolerated dose of olanzapine in the phase I trial, a phase II trial was performed for the prevention of chemotherapy-induced nausea and vomiting in patients receiving their first course of either highly emetogenic or moderately emetogenic chemotherapy. Olanzapine was added to granisetron and dexamethasone prechemotherapy and to dexamethasone postchemotherapy. CR (no emesis, no rescue) was 100% for the acute period (24 hours postchemotherapy), 80% for the delayed period (days 2-5 postchemotherapy), and 80% for the overall period (0-120 hours postchemotherapy) in ten patients receiving highly emetogenic chemotherapy (cisplatin, =70 mg/m2). CR was also 100% for the acute period, 85% for the delayed period, and 85% for the overall period in 20 patients receiving moderately emetogenic chemotherapy (doxorubicin, =50 mg/m2). Nausea was very well controlled in the patients receiving highly emetogenic chemotherapy, with no patient having nausea (0 on a scale of 0-10, M. D. Anderson Symptom Inventory [MDASI]) in the acute or delayed periods. Nausea was also well controlled in patients receiving moderately emetogenic chemotherapy, with no nausea in 85% of patients in the acute period and in 65% in the delayed and overall periods. There were no grade 3 or 4 toxicities. Based on these data, olanzapine appeared to be safe (sedation was the only dose-limiting toxicity) and effective in controlling acute and delayed chemotherapy-induced nausea and vomiting in patients receiving highly emetogenic and moderately emetogenic chemotherapy.[111] Management of Chemotherapy-induced Nausea and Vomiting Current guidelines [112,113] recommend that prechemotherapy management of chemotherapy-induced nausea and vomiting (CINV) be based on the emetogenic potential of the chemotherapy agent(s) selected. For patients receiving regimens with high emetogenic potential, the combination of a 5-HT3 receptor antagonist, aprepitant, and dexamethasone is recommended prechemotherapy; lorazepam may also be used. Aprepitant and dexamethasone are recommended postchemotherapy for the prevention of delayed emesis. For patients receiving moderately emetogenic chemotherapy, the combination of a 5-HT3 receptor antagonist and dexamethasone should be used prechemotherapy, with or without lorazepam. Patients receiving the combination of an anthracycline and cyclophosphamide and select patients receiving certain other agents of moderate emetic risk, such as cisplatin (<50 mg/m2) or doxorubicin, should also receive aprepitant. Postchemotherapy, a 5-HT3 receptor antagonist, dexamethasone, or both are recommended for the prevention of delayed emesis. For regimens with low emetogenic potential, dexamethasone is recommended with or without lorazepam. For regimens with minimal emetogenic risk, no prophylaxis is suggested.[112,113] Antiemetic guidelines [112,113] have included the available oral 5-HT3 receptor antagonists as optional therapy for the prevention of delayed emesis, but the level of evidence supporting this practice is low.[45] Clinicians and other health care professionals who are involved in administering chemotherapy should be aware that studies have strongly suggested that patients experience more acute and delayed chemotherapy-induced nausea and vomiting than is perceived by practitioners.[114,45,115] One study suggested that patients who are highly expectant of experiencing nausea appear to experience more postchemotherapy nausea.[116] In addition, the current and new agents have been used as prophylaxis for acute and delayed chemotherapy-induced nausea and vomiting and have not been studied for use in established chemotherapy-induced nausea and vomiting.[45,46] One study reported the effective use of intravenous palonosetron and dexamethasone for the prevention of chemotherapy-induced nausea and vomiting in patients receiving multiple-day chemotherapy.[117] Pre- and postchemotherapy recommendations by emetogenic potential are summarized in Table 3, Antiemetic Recommendations by Emetic-Risk Categories. Table 3. Antiemetic Recommendations by Emetic Risk Categoriesa
References:
Nausea, Vomiting, Constipation, and Bowel Obstruction in Advanced CancerFrequency Nausea and vomiting is a common symptom in patients with advanced cancer, occurring in approximately 21% to 68% of these patients.[1,2] The underlying pathophysiology and treatment differs somewhat from nausea related to radiation treatment or chemotherapy. Chronic nausea can significantly impair a patient's quality of life. Pathophysiology and Causes Chronic nausea in the setting of advanced cancer is often multifactorial in origin.[1,2,3] Medications, including some that are frequently prescribed in the setting of advanced cancer, such as opioids, nonsteroidal anti-inflammatory drugs, and selective serotonin reuptake inhibitor (SSRI) antidepressants may be responsible. In the case of opioids, nausea frequently resolves spontaneously a few days after initiation of treatment. In some cases, however, it may persist. Nausea resulting from the accumulation of active opioid metabolites (morphine-6-glucuronide) has been described,[4] and patients with impaired renal function may be at increased risk. Opioids invariably produce constipation if prophylactic measures are not taken (namely the use of a regular laxative regimen) and constipation is one of the most common causes of nausea in patients with advanced cancer.[5,6,7,8] Opioid-induced gastrointestinal (GI) motility problems may compound the problem of diminished GI motility that many patients experience as part of the anorexia-cachexia syndrome of advanced cancer. The autonomic dysfunction that often accompanies this syndrome results in decreased GI motility, early satiety, and chronic nausea.[9,10,11] Other causes of chronic nausea in these patients include raised intracranial pressure (from metastatic brain disease or primary brain tumors), metabolic abnormalities such as hypercalcemia, hyponatremia and uremia, dehydration, malignant bowel obstruction, gastroduodenal ulcers, and infections of the mouth, pharynx, or esophagus.[12] Nausea, like many other symptoms, may have psychological undercurrents that either exacerbate or induce chronic nausea. Assessment A comprehensive history that includes determining the frequency and effectiveness of bowel movements and laxative therapy is essential. Concurrent medications should be reviewed and the frequency and nature of nausea and vomiting should be documented. Examination should, among others, attempt to exclude bowel obstruction, fecal impaction, dehydration, and raised intracranial pressure. History and physical examination are poor at determining the extent of constipation.[5] A plain flat-plate x-ray of the abdomen can be very useful to this end.[13] Surgical x-ray views of the abdomen may be helpful if a bowel obstruction is suspected. Investigations to determine blood levels of electrolytes, calcium and renal parameters may also be helpful. Management Management centers on identifying the underlying causes, addressing these when possible, and controlling the symptoms.[1,2] A basic working knowledge of the emetic pathways and identification of possible underlying causes should guide antiemetic selection. Multiple antiemetic regimens have been proposed for the management of chronic nausea in the setting of advanced cancer. Prospective studies comparing one regimen with another are lacking. Metoclopramide or domperidone are generally recommended as first-line agents because they improve GI motility and act on the chemoreceptor trigger zone (as a result of their antidopaminergic properties).[14] Metoclopramide can be administered orally or parenterally (subcutaneously or intravenously [IV]) at doses of 10 mg, 4 times a day, or on an every-4-hour basis, depending on the severity of the nausea. Rescue doses should also be ordered on an as-needed basis to manage the episodic worsening of nausea that may occur. Extrapyramidal-related adverse effects are a potential complication of these medications, but appear to occur infrequently. Domperidone, which is currently unavailable in the United States, is associated with fewer of these adverse effects. Unfortunately, this drug is not available in a parenteral formulation. Dimenhydrinate (Dramamine) or antihistamine agents may be used if a complete bowel obstruction is suspected (in which case prokinetic agents are contraindicated) or if patients are intolerant to other antiemetic agents. Haloperidol, a potent antidopamine agent, may be considered if bowel obstruction is the underlying problem.[15] The phenothiazine drugs are sometimes used,[16] but the high incidence of adverse effects, such as somnolence and anticholinergic-related effects (orthostatic hypotension and confusion), limit their role. Chlorpromazine has modest antiemetic activity but a high incidence of sedation, postural hypotension, and anticholinergic adverse effects, while piperazine derivatives such as prochlorperazine are stronger antiemetics but cause more extrapyramidal side effects. Hyoscine butylbromide, on the other hand, can be useful for patients experiencing colic from complete bowel obstruction. A continuous parenteral infusion of metoclopramide, at doses of 60 to 120 mg/day, may be helpful for patients with intractable chronic nausea.[17] The judicious use of corticosteroids such as dexamethasone in selected patients may be useful in conjunction with a more traditional antiemetic, although one study has suggested that dexamethasone was not better than placebo in patients who were not controlled with metoclopramide.[18] The exact mechanism of action and the optimal dose of corticosteroids for this indication are not known. In contrast to radiation therapy- or chemotherapy-induced nausea, the role of 5-HT3 receptor antagonists (such as ondansetron) is not clear in the setting of chronic nausea in advanced cancer, but appears to be limited to a small number of highly selected cases, specifically those that have failed all other treatments.[19] A case series study has suggested an antiemetic effect for olanzapine (an atypical antipsychotic) in advanced cancer patients being treated with opioids who are complaining of apparent opiate-induced nausea. However, further study and comparison with standard management are required.[20] The management of constipation can be divided into general interventions and therapeutic measures.[21] The general interventions include the prevention of constipation by initiating regular laxative regimens, particularly in patients on opioid treatment, and where possible, the elimination of medical factors that may be contributing to constipation (e.g., discontinuation of nonessential constipating drugs). Prophylactic laxative regimens may consist of stool softeners such as docusate and bowel stimulants such as sennosides. Occasionally lactulose may be added. If necessary, a hyperosmolar laxative such as lactulose or polyethylene glycol may be added.[22] These regimens should be reviewed on a regular basis and their doses adjusted, depending on the regularity of bowel movements. High-fiber diets, while generally recommended, may be difficult for patients with very advanced cancer. Bulk agents such as psyllium or cellulose are unsuitable for patients with advanced cancer because the high fluid intake required with these agents is often intolerable to patients. (Refer to the PDQ summaries on Gastrointestinal Complications and Pain for further information on the management of constipation caused by opioids.) Therapeutic interventions for the routine management of constipation may be administered orally or rectally. Oral laxatives include bulk agents, osmotic agents, contact cathartics, and agents for colonic lavage. Saline laxatives, including sodium salts (sodium phosphate) and magnesium salts (magnesium citrate) may be useful to treat established constipation. Sodium phosphates are generally administered rectally as an enema, but oral solutions are also available. Magnesium citrate is generally administered orally and can be especially useful if the constipation is primarily in the proximal bowel. The contact cathartic bisacodyl, available as a suppository, may also be useful for treating established constipation. Once the constipation is cleared, the background laxative regimen (e.g., sennoside and docusate) should be reviewed with the view of optimizing it. The action of the saline and magnesium salts is not physiological and regular, ongoing administration should be avoided. Saline laxatives should be used with caution in patients with renal impairment or cardiac failure. Mineral oil enemas are used occasionally and act as both lubricants and stool softeners. They may interfere with the absorption of fat-soluble vitamins, however, and there is a risk of lipoid pneumonia in debilitated patients. The use of enemas and rectal suppositories is usually limited to the acute, short-term management of more severe episodes of constipation. Patients with neurogenic bowel problems (e.g., patients with irreversible spinal cord compression), however, often require regular, ongoing treatment with suppositories as part of their bowel care. The rectal route is contraindicated in patients with mucosal integrity/bowel-wall compromise. (Refer to the PDQ summary on Gastrointestinal Complications for further information.) There have been no adequate comparative studies between the various laxatives to make evidence-based recommendations on which laxative regimen is optimal. Patients with advanced cancer are at risk of becoming constipated and generally require a regular bowel regimen, even if they are not eating. This need is amplified when they are on opioid treatment. On occasion, patients may present with a refractory narcotic bowel syndrome despite aggressive bowel care. Methylnaltrexone, a quaternary derivative of naltrexone, is an opioid antagonist that does not cross the blood-brain barrier. Preliminary studies suggest that it may be effective when given subcutaneously in the management of opioid-associated constipation without causing opioid withdrawal.[23,24,25] Methylnaltrexone should be avoided in cases of bowel obstruction and suspected bowel obstruction. This has not been studied in children. Malignant Bowel Obstruction The initial approach to assessing and managing malignant bowel obstruction in the advanced cancer patient involves determining whether the obstruction is reversible or not, and whether the obstruction is partial or complete.[26,27,28] Suitability for surgery such as resection or intestinal bypassing should be assessed. Several medical options are available to improve the comfort of patients with inoperable bowel obstructions.[29,30] Less aggressive surgical procedures such as the insertion of a venting gastrostomy tube can provide considerable relief. The creation of ostomies, where the obstruction is complete and irreversible, may also provide relief. Nasogastric tubes may be used temporarily until the obstruction resolves, but where the obstruction is irreversible, other options such as the insertion of a gastrostomy tube should be considered. Antiemetic agents with prokinetic properties are relatively contraindicated in the presence of a complete obstruction, and alternative agents such as an antihistamine or haloperidol may be required. Clinical experience suggests that corticosteroids (e.g., dexamethasone at a starting dose of 6-10 mg subcutaneously, 3-4 times a day) may be useful for malignant bowel obstruction.[26,27] The optimal dose and duration of treatment has not been clarified. Hydration and drugs such as opioids and antiemetics should be administered via routes other than the oral route. The subcutaneous route can be very convenient and effective for both hydration and opioid administration. This route is as effective as IV administration, is less invasive, and requires less maintenance than the IV route. Octreotide, a somatostatin analog, can be useful at doses of 100 to 200 µg subcutaneously, 3 times a day, for refractory obstruction.[26,27,31] In the United States, octreotide is often administered as a continuous infusion. If the obstruction causes severe colic, hyoscine butylbromide may be considered. The use of colonic endoluminal stenting devices in selected patients is gaining increasing attention.[32,33] References:
Nonpharmacologic Management of Nausea and VomitingNonpharmacologic strategies are also used to manage nausea and vomiting. These include dietary alterations, hypnosis, acupuncture, acupressure,[1] relaxation techniques, behavioral therapy, and guided imagery. (Refer to the PDQ summary on Acupuncture for more information.) Guided imagery, hypnosis, and systematic desensitization as means to progressive muscle relaxation have been the most frequently studied treatments for anticipatory nausea and vomiting (ANV) and are the recommended treatments for this classically conditioned response. (Refer to the Treatment of ANV section of this summary for more information.) Electroacupuncture has a demonstrated benefit for acute vomiting but not for acute nausea. Acupressure appears to reduce the severity of acute nausea but has not been tested in a placebo-controlled trial. A review of the literature suggests the need for further studies of electroacupuncture in patients also receiving state-of-the-art antiemetic pharmacologic treatment, to investigate clinical usefulness.[2] References:
Radiation TherapyCorrelates Patients receiving radiation to the gastrointestinal (GI) tract or brain have the greatest potential for nausea/vomiting as a side effect. Because cells of the GI tract are dividing quickly, they are quite sensitive to radiation therapy. Radiation to the brain is believed to stimulate the brain's vomiting center or chemotherapy trigger zone. Similar to chemotherapy, radiation dose factors also play a role in determining the possible occurrence of nausea and vomiting. In general, the higher the daily fractional dose and the greater the amount of tissue that is irradiated, the higher the potential for nausea and vomiting. In addition, the larger the amount of GI tract irradiated (particularly for fields that include the small intestine and stomach), the higher the potential for nausea and vomiting. Total-body irradiation before bone marrow transplant, for example, has a high probability of inducing nausea and vomiting as acute side effects. Prevalence Nausea and vomiting from radiation may be acute and self-limiting, usually occurring 30 minutes to several hours after treatment. Patients report that symptoms improve on days that they are not being treated. There are also cumulative effects that may occur in patients receiving radiation therapy to the GI tract.[1] Treatment Complete control rates with 5-HT3 antagonists for total-body irradiation vary from 50% to 90%.[2,3,4] The role of corticosteroids in combination with 5-HT3 antagonists has not been studied. References:
Current Clinical TrialsCheck NCI's PDQ Cancer Clinical Trials Registry for U.S. supportive and palliative care trials about nausea and vomiting that are now accepting participants. The list of trials can be further narrowed by location, drug, intervention, and other criteria. General information about clinical trials is also available from the NCI Web site. Get More Information From NCICALL 1-800-4-CANCER For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. The call is free and a trained Cancer Information Specialist is available to answer your questions. CHAT ONLINE The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 9:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer. WRITE TO US For more information from the NCI, please write to this address:
SEARCH THE NCI WEB SITE The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our "Best Bets" search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results. There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment. FIND PUBLICATIONS The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615. Changes to This Summary (04 / 22 / 2009)The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above. PREVENTION OF ACUTE/DELAYED EMESIS Added text to state that one study suggested patients who are highly expectant of experiencing nausea appear to experience more postchemotherapy nausea (cited Colagiuri et al. as reference 116). Questions or Comments About This SummaryIf you have questions or comments about this summary, please send them to Cancer.gov through the Web site's Contact Form. We can respond only to email messages written in English. More InformationABOUT PDQ
ADDITIONAL PDQ SUMMARIES
IMPORTANT: This information is intended mainly for use by doctors and other health care professionals. If you have questions about this topic, you can ask your doctor, or call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). Date Last Modified: 2009-04-22
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