What is the most important information I should know about trihexyphenidyl?
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
What is trihexyphenidyl?
Trihexyphenidyl is used to treat symptoms of Parkinson's disease (stiffness, tremors, spasms, poor muscle control).
Trihexyphenidyl is also used to treat and prevent Parkinson-like symptoms that are caused by using certain anti-psychotic medications.
Trihexyphenidyl may also be used for purposes not listed in this medication guide.
What should I discuss with my healthcare provider before taking trihexyphenidyl?
You should not use trihexyphenidyl if you are allergic to it, or if you have:
Tell your doctor if you have ever had:
- glaucoma;
- an enlarged prostate;
- urination problems;
- a bowel obstruction, severe constipation, or toxic megacolon;
- epilepsy or other seizure disorder;
- heart problems;
- coronary artery disease (clogged arteries);
- high blood pressure;
- alcoholism; or
- a problem with your nerves, brain, or spinal cord.
Older adults may be more sensitive to the effects of this medicine.
Tell your doctor if you are pregnant or breast-feeding.
How should I take trihexyphenidyl?
Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.
Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).
Your doctor will tell you whether you should take trihexyphenidyl before or after a meal.
Take the medicine with food if it upsets your stomach.
If trihexyphenidyl causes your mouth to feel dry, you may need to take it before meals.
You may also use mints, chewing gum, or water if you have a very dry mouth or you feel very thirsty.
The pressure inside your eyes will need to be checked while you are taking trihexyphenidyl.
You should not stop using trihexyphenidyl suddenly. Stopping suddenly may make your condition worse.
Store at room temperature away from moisture, heat, and light. Do not freeze.
What happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may include severe drowsiness, fever, dilated pupils, feeling hot, paleness in your face, dry skin and mouth, hallucinations, paranoia, agitation, seizure, or numbness in or around your mouth, nose, or throat.
What should I avoid while taking trihexyphenidyl?
Avoid becoming overheated or dehydrated during exercise and in hot weather. Trihexyphenidyl can decrease sweating and you may be more prone to heat stroke.
Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.
Avoid using cannabis, CBD, or marijuana while taking trihexyphenidyl.
Avoid drinking alcohol. It may increase your risk of side effects.
What are the possible side effects of trihexyphenidyl?
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
- blurred vision, tunnel vision, eye pain, or seeing halos around lights;
- hot and dry skin, or a lack of sweating even if you feel hot;
- rapid or jerky repetitive involuntary movement;
- severe constipation;
- painful or difficult urination;
- unusual thoughts or behavior;
- confusion, memory problems; or
-
severe nervous system reaction --very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.
Common side effects may include:
- blurred vision;
- dry mouth;
- constipation, decreased urination;
- dizziness, drowsiness, weakness;
- nausea, vomiting;
- headache; or
- feeling restless or nervous.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect trihexyphenidyl?
Using trihexyphenidyl with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.
Tell your doctor about all your other medicines, especially:
- medicine to treat depression, anxiety, mood disorders, or mental illness;
- cold or allergy medicine (Benadryl and others);
- other medicines to treat Parkinson's disease;
- medicine to treat stomach problems, motion sickness, or irritable bowel syndrome;
- medicine to treat overactive bladder; or
- bronchodilator asthma medication.
This list is not complete. Other drugs may affect trihexyphenidyl, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
Where can I get more information?
Your pharmacist can provide more information about trihexyphenidyl.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2020 Cerner Multum, Inc. Version: 6.01. Revision date: 1/28/2019.
