Trihexyphenidyl and Alcohol: What You Need to Know

If you’ve been prescribed trihexyphenidyl for Parkinson’s or another condition, you might wonder whether a glass of wine or a beer is okay. The short answer: mixing alcohol with this drug can make side effects worse and put you at risk for accidents. Below we break down the main concerns and give you easy steps to stay safe.

How Alcohol Changes Trihexyphenidyl’s Effects

Trihexyphenidyl is an anticholinergic medication that blocks certain brain signals to reduce tremors and stiffness. Alcohol also messes with brain chemistry, especially the same pathways that control balance and alertness. When you combine the two, you can feel stronger drowsiness, dizziness, or blurred vision than you’d expect from either alone.

One of the biggest worries is impaired coordination. Both substances can slow reaction time, so doing anything that requires focus—driving, operating machinery, or even climbing stairs—becomes risky. Some people also notice a jump in heart rate or blood pressure fluctuations, which can be dangerous for anyone with heart problems.

Common Symptoms to Watch For

If you’ve had a drink while on trihexyphenidyl, keep an eye out for these signs:

• Excessive sleepiness or feeling “out of it.”
• Confusion, trouble remembering simple tasks.
• Headaches or a pounding feeling in your head.
• Dry mouth, flushed skin, or a rapid heartbeat.
• Difficulty focusing your eyes, which can make reading or watching TV uncomfortable.

Any of these symptoms that feel stronger than usual should prompt you to stop drinking and contact your doctor.

It’s also worth noting that alcohol can increase the risk of dehydration, which could make the dry‑mouth side effect of trihexyphenidyl worse. Staying hydrated helps, but the safest move is to limit alcohol altogether while you’re on the medication.

In rare cases, mixing these substances can lead to serious problems like severe low blood pressure, fainting, or even seizures. If you ever feel faint, lose consciousness, or have a seizure, call emergency services right away.

Bottom line: if you’re on trihexyphenidyl, treat alcohol like a red flag. A small amount might seem harmless, but the combined effect can be unpredictable. Talk with your healthcare provider about what level, if any, is safe for you. They might suggest a brief pause from drinking while your dose stabilizes.

Remember, the goal is to keep you moving comfortably without putting your safety at risk. If you’re unsure, err on the side of caution and skip the drink. Your health will thank you in the long run.