Trihexyphenidyl hydrochloride and Drowsiness - a phase IV clinical study of FDA data

Summary:

Drowsiness is reported as a side effect among people who take Trihexyphenidyl hydrochloride (trihexyphenidyl hydrochloride), especially for people who are male, 60+ old, have been taking the drug for < 1 month also take Amisulpride, and have Schizophrenia.

The phase IV clinical study analyzes which people have Drowsiness when taking Trihexyphenidyl hydrochloride. It is created by eHealthMe based on reports of 1,053 people who have side effects when taking Trihexyphenidyl hydrochloride from the FDA, and is updated regularly.

What is Trihexyphenidyl hydrochloride?

Trihexyphenidyl hydrochloride has active ingredients of trihexyphenidyl hydrochloride. It is often used in parkinson's disease. eHealthMe is studying from 1,118 Trihexyphenidyl hydrochloride users. Check the latest studies of Trihexyphenidyl hydrochloride.

What is Drowsiness?

Drowsiness is found to be associated with 2,865 drugs and 4,797 conditions by eHealthMe. Check the latest studies of Drowsiness.

On Jul, 07, 2026

1,053 people reported to have side effects when taking Trihexyphenidyl hydrochloride.
Among them, 33 people (3.13%) have Drowsiness.

Could Trihexyphenidyl hydrochloride cause Drowsiness?

Among these 33 people:

How long have people been on Trihexyphenidyl hydrochloride when they have Drowsiness? *

What is the gender of people who have Drowsiness when taking Trihexyphenidyl hydrochloride? *

female: 50 %
male: 50 %

What is the age of people who have Drowsiness when taking Trihexyphenidyl hydrochloride? *

What are other drugs people take besides Trihexyphenidyl hydrochloride? *

What are other side effects people have besides Drowsiness? *

Hypotension (abnormally low blood pressure): 5 people, 15.15%
Confusional State: 5 people, 15.15%
Nausea (feeling of having an urge to vomit): 4 people, 12.12%
Diarrhea: 4 people, 12.12%
Constipation: 4 people, 12.12%
Stress And Anxiety: 3 people, 9.09%
Hallucination, Visual (seeing things that aren't there): 3 people, 9.09%
Hallucinations (sensations that appear real but are created by your mind): 3 people, 9.09%
Headache (pain in head): 3 people, 9.09%
Salivary Hypersecretion (excess saliva secretion): 3 people, 9.09%

What are the existing conditions these people have? *

Schizophrenia (a mental disorder characterized by a breakdown of thought processes): 5 people, 15.15%
Epilepsy (common and diverse set of chronic neurological disorders characterized by seizures): 3 people, 9.09%
Bipolar Disorder (mood disorder): 2 people, 6.06%
Stress And Anxiety: 2 people, 6.06%
Seasonal Allergy (allergic condition due to certain season): 2 people, 6.06%
Schizophrenia, Paranoid Type (delusions and auditory hallucinations but relatively normal intellectual functioning and expression of affect): 2 people, 6.06%
Psychotic Disorder: 2 people, 6.06%
Poor Quality Sleep: 2 people, 6.06%
Circadian Rhythm Sleep Disorder (family of sleep disorders affecting, among other things, the timing of sleep): 2 people, 6.06%
Depression: 2 people, 6.06%

* Approximation only. Some reports may have incomplete information.

Do you take Trihexyphenidyl hydrochloride and have Drowsiness?

- Check whether Drowsiness is associated with a drug or a condition
- Predict drug outcomes for up to one year with AI
- Get an AI agent to monitor your drugs continuously

Related studies:

Effectiveness of, long term effects of, and alternative drugs to Trihexyphenidyl hydrochloride:

Trihexyphenidyl hydrochloride (1,118 reports)

Drowsiness treatments and more:

Drowsiness (269,040 reports)

Browse all side effects of Trihexyphenidyl hydrochloride:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Browse all the drugs that are associated with Drowsiness:

Drowsiness (2,865 drugs)

Browse all the conditions that are associated with Drowsiness:

Drowsiness (4,797 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on trihexyphenidyl hydrochloride (the active ingredients of Trihexyphenidyl hydrochloride) and Trihexyphenidyl hydrochloride (the brand name). Other drugs that have the same active ingredients (e.g. generic drugs) are not considered. Dosage of drugs is not considered in the study.

How to use the study?

DO NOT STOP MEDICATIONS without first consulting your doctor. If there are any serious or long term adverse effects discovered in the study, discuss the study with your doctor to ensure that proper medication management will be in place if applicable.

Who is eHealthMe?

With medical big data and proven AI/ML algorithms, eHealthMe provides a platform for everyone to run phase IV clinical trials. We study millions of patients and 5,000 more each day. Results of our real-world drug study have been referenced on 800+ peer-reviewed medical publications, including The Lancet, Mayo Clinic Proceedings, and Nature. Our analysis results are available to researchers, health care professionals, patients (testimonials), and software developers (open API).

WARNING, DISCLAIMER, USE FOR PUBLICATION

WARNING: Please DO NOT STOP MEDICATIONS without first consulting a physician since doing so could be hazardous to your health.

DISCLAIMER: All material available on eHealthMe.com is for informational purposes only, and is not a substitute for medical advice, diagnosis, or treatment provided by a qualified healthcare provider. All information is observation-only. Our phase IV clinical studies alone cannot establish cause-effect relationship. Different individuals may respond to medication in different ways. Every effort has been made to ensure that all information is accurate, up-to-date, and complete, but no guarantee is made to that effect. The use of the eHealthMe site and its content is at your own risk.

If you use this eHealthMe study on publication, please acknowledge it with a citation: study title, URL, accessed date.