Ritonavir

IMPORTANT WARNING:

Taking ritonavir with certain other medications may cause serious or life-threatening side effects. Tell your doctor if you are taking any of the following medications: ergot medications such as dihydroergotamine (D.H.E. 45, Migranal), ergotamine (Ergomar, in Cafergot, in Migergot), ergonovine, and methylergonovine (Methergine); medications for irregular heartbeat such as amiodarone (Cordarone, Nexterone, Pacerone), flecainide, propafenone (Rhythmol), and quinidine (in Nuedexta); and sedatives or sleeping pills such as midazolam (Versed) and triazolam (Halcion). Your doctor will probably tell you not to take ritonavir if you are taking any of these medications.

WHY is this medicine prescribed?

Ritonavir is used along with other medications to treat human immunodeficiency virus (HIV) infection. Ritonavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although ritonavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other lifestyle changes may decrease the risk of transmitting the HIV virus to other people.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Ritonavir comes as a capsule, a tablet, and a solution (liquid) to take by mouth. It is usually taken twice a day with meals. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take ritonavir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of ritonavir and gradually increase your dose, not more often than once every 2 to 3 days. Follow these directions carefully.

Swallow ritonavir tablets whole. Do not split, chew, or crush them.

If you are taking the oral solution, use a dose measuring spoon, syringe, or cup to measure the correct amount of liquid needed for each dose. Do not use a regular household spoon. You may take the solution by itself, or you may improve the taste by mixing it with 8 ounces of chocolate milk or Ensure or Advera brand dietary supplements. If you mix the medication with one of these liquids, you must drink the mixture no longer than 1 hour after you mix it.

If your doctor tells you to stop taking ritonavir capsules and start taking the tablets instead, you may experience more side effects such as nausea, vomiting, stomach pain, and diarrhea shortly after you switch. These symptoms may improve as your body adjusts to the tablets.

Continue to take ritonavir even if you feel well. Do not stop taking ritonavir without talking to your doctor. If you miss doses, take less than the prescribed dose, or stop taking ritonavir, your condition may become more difficult to treat.

What SPECIAL PRECAUTIONS should I follow?

Before taking ritonavir,

• tell your doctor and pharmacist if you are allergic to ritonavir, any other medications, or any of the ingredients in ritonavir tablets, capsules, or solution. Ask your pharmacist for a list of the ingredients.

• tell your doctor if you are taking any of the medications in the IMPORTANT WARNING section or any of the following: alfuzosin (Uroxatral), apalutamide (Erleada), cisapride (Propulsid) (not available in U.S.), colchicine (Colcrys, Mitigare) in people with kidney or liver disease, dronedarone (Multaq), lomitapide (Juxtapid), lovastatin (Altoprev), lurasidone (Latuda), pimozide (Orap), ranolazine (Ranexa), sildenafil (only Revatio brand used for lung disease), simvastatin (Zocor, in Vytorin), St. John's wort, or voriconazole (Vfend). Your doctor will probably tell you not to take ritonavir if you are taking one or more of these medications.

• also tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven) and rivaroxaban (Xarelto); antidepressants such as amitriptyline, bupropion (Aplenzin, Forfivo XL, Wellbutrin, Zyban, others), desipramine (Norpramin), fluoxetine (Prozac), nefazodone, nortriptyline, paroxetine (Paxil), and trazodone; atovaquone (Mepron, in Malarone); bedaquiline (Sirturo); beta-blockers such as metoprolol (Lopressor, Toprol XL, in Dutoprol, in Lopressor HCT) and timolol; bosentan (Tracleer); buspirone; calcium channel blockers such as diltiazem (Cardizem, Cartia, Tiazac, others), nifedipine (Adalat, Afeditab CR, Procardia), and verapamil (Calan, Covera, Verelan, in Tarka); cholesterol-lowering medications such as atorvastatin (Lipitor, in Caduet) and rosuvastatin (Crestor); clarithromycin (Biaxin, in PrevPac); clorazepate (Gen-Xene, Tranxene); colchicine (Colcrys, Mitigare); certain medications for cancer such as abemaciclib (Verzenio), dasatinib (Sprycel), encorafenib (Braftovi), ibrutinib (Imbruvica), ivosidenib (Tibsovo), neratinib (Nerlynx), nilotinib (Tasigna), venetoclax (Venclexta), vinblastine, and vincristine; dexamethasone; diazepam (Diastat, Valium); digoxin (Lanoxin); dronabinol (Marinol); elagolix (Orilissa); estazolam; fentanyl (Duragesic, Subsys), fostamatinib (Tavalisse), certain medications for hepatitis C virus (HCV) such as boceprevir (no longer available in the U.S.; Victrelis), glecaprevir and pibrentasvir (Mavyret), and simeprevir (no longer available in U.S.; Olysio); itraconazole (Onmel, Sporanox); ketoconazole (Nizoral); lidocaine (Lidoderm; in Xylocaine with Epinephrine); other medications for HIV such as atazanavir (Reyataz, in Evotaz), darunavir (Prezista, in Prezcobix), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), maraviroc (Selzentry), saquinavir (Invirase), and tipranavir (Aptivus); medications for erectile dysfunction such as avanafil (Stendra), sildenafil (Viagra), tadalafil (Adcirca, Cialis), and vardenafil (Levitra); medications that suppress the immune system such as cyclosporine (Gengraf, Neoral, Sandimmune), sirolimus (Rapamune) and tacrolimus (Astagraf XL, Prograf); certain medications for seizures such as carbamazepine (Epitol, Equetro, Tegretol, others), clonazepam (Klonopin), divalproex (Depakote), ethosuximide (Zarontin), lamotrigine (Lamictal), and phenytoin (Dilantin, Phenytek); meperidine (Demerol); methadone (Dolophine, Methadose); methamphetamine (Desoxyn); mexiletine; perphenazine; quetiapine (Seroquel); quinine (Qualaquin); rifabutin (Mycobutin); rifampin (Rifadin, Rimactane, in Rifamate, in Rifater); risperidone; salmeterol (Serevent, in Advair); oral or inhaled steroids such as betamethasone, budesonide (Pulmicort), ciclesonide (Alvesco, Omnaris), dexamethasone, fluticasone (Flonase, Flovent, in Advair), methylprednisolone (Medrol). mometasone (in Dulera). prednisone, and triamcinolone; theophylline (Theo 24, Uniphyl, others); thioridazine; and zolpidem (Ambien, Edluar, Intermezzo, others). Many other medications may also interact with ritonavir, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

• if you are taking ritonavir oral suspension, also tell your doctor if you are taking disulfiram (Antabuse) or metronidazole (Flagyl, Nuvessa, Vandazole).

• you should know that ritonavir may decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, or injections). Talk to your doctor about using another form of birth control.

• tell your doctor if you have or have ever had a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death), diabetes, hemophilia, high cholesterol or triglycerides (fats) in the blood, or heart or liver disease, including hepatitis B or C.

• tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking ritonavir, call your doctor immediately. You should not breastfeed if you are infected with HIV or if you are taking ritonavir.

• you should be aware that your body fat may increase or move to different areas of your body, such as your upper back, neck (''buffalo hump''), breasts, and around your stomach. You may notice a loss of body fat from your face, legs, and arms.

• you should know that you may experience hyperglycemia (increases in your blood sugar) while you are taking this medication, even if you do not already have diabetes. Tell your doctor immediately if you have any of the following symptoms while you are taking ritonavir: extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness. It is very important to call your doctor as soon as you have any of these symptoms, because high blood sugar that is not treated can cause a serious condition called ketoacidosis. Ketoacidosis may become life-threatening if it is not treated at an early stage. Symptoms of ketoacidosis include dry mouth, nausea and vomiting, shortness of breath, breath that smells fruity, and decreased consciousness.

• you should know that while you are taking medications to treat HIV infection, your immune system may get stronger and begin to fight other infections that were already in your body. This may cause you to develop symptoms of those infections. If you have new or worsening symptoms after starting treatment with ritonavir, be sure to tell your doctor.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Ritonavir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• diarrhea
• gas
• heartburn
• change in ability to taste food
• headache
• numbness, burning, or tingling of the hands, feet, or area around the mouth
• muscle or joint pain
• stomach pain, nausea, and vomiting

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment:

• blistering or peeling of the skin
• rash
• hives
• swelling of the eyes, face, tongue, lips, or throat
• tightening of the throat
• difficulty breathing or swallowing
• nausea
• vomiting
• stomach pain
• excessive tiredness
• lack of energy
• loss of appetite
• pain in the upper right part of the stomach
• yellowing of the skin or eyes
• dizziness
• lightheadedness
• loss of consciousness
• irregular heartbeat

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Ritonavir may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store the tablets and solution at room temperature. Do not refrigerate the solution and do not let it get too hot or too cold. It is best to refrigerate ritonavir capsules, but you may also store them at room temperature for up to 30 days.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

It is especially important to get medical help right away if a child drinks more than the usual dose of the solution. The solution contains a large amount of alcohol that could be very harmful to a child.

Symptoms of overdose may include the following:

• numbness, burning, or tingling of the hands or feet

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to ritonavir.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.