Drug Interaction Report

Trihexyphenidyl may increase the effects of phenylephrine on your blood pressure and heart rate. Before receiving these medications, you should let your doctor know if you have high blood pressure or heart disease. You may not be able to use one or both of these medications, or you may need closer monitoring by your doctor in order to use these medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Ask your doctor before using trihexyphenidyl together with ethanol (alcohol). Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking trihexyphenidyl. You should be warned not to exceed recommended dosages and to avoid activities requiring mental alertness. If your doctor prescribes these medications together, you may need a dose adjustment to safely take this combination. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Both phenylephrine and caffeine can increase blood pressure and heart rate, and combining them may enhance these effects. Talk to your doctor before using these medications, especially if you have a history of high blood pressure or heart disease. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if your condition changes or you experience increased side effects. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.