Drug Interaction Report

Using amantadine together with amitriptyline may increase side effects such as dry mouth, constipation, difficulty urinating, heat intolerance, confusion, and blurred vision. More severe side effects may rarely include hallucinations, seizures, irregular heart rhythm, and heat stroke. Side effects may be more likely to occur in the elderly or those with a debilitating condition. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. You should avoid or limit the use of alcohol while being treated with these medications. Also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medications affect you. 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.

Using amantadine together with perphenazine may increase side effects such as dry mouth, constipation, difficulty urinating, heat intolerance, confusion, and blurred vision. More severe side effects may rarely include hallucinations, seizures, irregular heart rhythm, and heat stroke. Side effects may be more likely to occur in the elderly or those with a debilitating condition. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. You should avoid or limit the use of alcohol while being treated with these medications. Also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medications affect you. 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.

Before taking amitriptyline, tell your doctor if you also use perphenazine. You may need dose adjustments or special tests in order to safely take both medications together. This combination should be used with caution, particularly in the elderly. You should notify your doctor promptly if you have signs of bladder problems, dry mouth, stomach pain, fever, blurred vision, confusion, dizziness, or reduced heart rate. You should avoid driving until you know how these medications will affect you. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using your medications without first talking to your doctor.

Ask your doctor before using amitriptyline together with ethanol (alcohol), this can alter the effects of amitriptyline 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.

Ask your doctor before using perphenazine together with ethanol (alcohol). This can cause uncontrollable movements, agitation, seizures, severe dizziness or fainting, coma, very deep sleep, irregular heartbeats, and high or low body temperature. Use caution when driving, operating machinery, or performing other hazardous activities, these medicaions may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities. 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.

Consumer information for this interaction is not currently available.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.