While adverse reactions to trihexyphenidyl are uncommon, some patients who take the drug may experience mild side effects, including difficulty urinating, upset stomach, dizziness, dry mouth, blurred vision, vomiting, headache, and constipation.
Less common but more serious side effects should be reported to your doctor immediately. Contact your doctor right away if you experience any of the following:
- Fast, irregular, or pounding heartbeat
- Delusions or hallucinations
Notify your doctor if your side effects become unmanageable. There may be additional side effects of taking Trihexyphenidyl. You should speak to your doctor about the risks of taking Trihexyphenidyl before beginning a prescription.
This is not a complete list of side effects. For more information, please visit the National Institutes of Health’s DailyMed webpage.