Known interactions between the following drugs: 4-Way Fast Acting, Etrafon

Amitriptyline is broken down into both active and inactive by-products by the liver--a process referred to a "drug metabolism". Perphenazine may interfere with the liver's ability to metabolize amitriptyline. As a result, blood levels of amitriptyline may become elevated and this could increase the risk for side effects. Potential side effects include drowsiness, dizziness, a dry mouth, and blurred vision. Other, more serious side effects include changes in blood pressure, seizures, and an abnormal heart rhythm. Your doctor may want to monitor you closely while these drugs are used together to make sure that you are not getting too much amitriptyline. If you are experiencing problems, it may be necessary to adjust the dose of amitriptyline. You may want to ask your healthcare provider about this potential interaction if you think you are having problems.

Catecholamines are referred to as "neurotransmitters"--chemicals produced by the body that carry messages to nerve cells located throughout the body. There are several different types of catecholamines and each has a specific effect, such as causing blood pressure to increase or making the heart beat faster. Phenylephrine mimics the effect of the catecholamines and is often used to increase blood pressure that has become dangerously low. Amitriptyline enhances the effects of certain catecholamines in the brain. When these drugs are used at the same time, you may be more likely to experience a change in blood pressure or an abnormal heart rhythm. If these drugs must be used together, your doctor may want to monitor your blood pressure and heart rate more frequently and adjust the dose of phenylephrine if needed. Phenylephrine is also an ingredient that is commonly contained in over-the-counter nasal decongestants and other products used to relieve cold and flu symptoms. To avoid potential problems, ask your doctor or pharmacist before using any over-the-counter drugs--including herbal supplements--while you are taking amitriptyline. Discuss this potential interaction with your healthcare provider at your next appointment, or sooner if you think you are having problems.