Drug Interaction Report

Using pentamidine together with protriptyline can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). Talk to your doctor if you have any questions or concerns. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these medications, whether together or alone. 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 protriptyline together with ethanol (alcohol), this can alter the effects of protriptyline and cause increased side effects. Call the doctor if you experience uneven heartbeats, extreme drowsiness, confusion, agitation, vomiting, blurred vision, sweating, muscle stiffness, feeling light-headed, and seizures. You should be warned not to exceed recommended dosages, to avoid alcohol, 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.