Trihexyphenidyl is used along with other medications to treat the symptoms of Parkinson's disease (PD; a disorder of the nervous system that causes difficulties with movement, muscle control, and balance) and to control extrapyramidal symptoms (tremor, slurred speech) caused by certain medications. Trihexyphenidyl is in a class of medications called antimuscarinics. It works by relaxing muscles and nerve impulses that control the function of muscles.
Trihexyphenidyl comes as a tablet and elixir (liquid) to take by mouth. It usually is taken with or without food three or four times a day. Take trihexyphenidyl at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take trihexyphenidyl exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Do not stop taking trihexyphenidyl suddenly without talking with your doctor, especially if you are also taking other medications. Sudden stoppage can cause symptoms of Parkinson's disease to return.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Before taking trihexyphenidyl,
Unless your doctor tells you otherwise, continue your normal diet.
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.
Trihexyphenidyl may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
Trihexyphenidyl may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.
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 ( Web Site ) or by phone (1-800-332-1088).
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
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. Web Site
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 ( Web Site) for more information if you do not have access to a take-back program.
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at Web Site. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to trihexyphenidyl.
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.
¶ This branded product is no longer on the market. Generic alternatives may be available.
AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Selected Revisions: July 15, 2018.