Drug Interactions between Fentanyl Transdermal System and isoniazid

Do not use alcohol or medications that contain alcohol while you are receiving treatment with fentaNYL. This may increase nervous system side effects such as drowsiness, dizziness, lightheadedness, difficulty concentrating, and impairment in thinking and judgment. In severe cases, low blood pressure, respiratory distress, fainting, coma, or even death may occur. You should also avoid consuming grapefruit and grapefruit juice, as this may increase the blood levels and effects of fentanyl. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. Do not use more than the recommended dose of fentaNYL, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.

Food can decrease the levels of isoniazid in your body. Taking isoniazid on an empty stomach (at least 30 minutes before or 2 hours after a meal) will make it easier for your body to absorb the medication. Avoid drinking alcohol while taking isoniazid because alcohol use may increase the risk of damage to your liver and your risk of experiencing a condition known as peripheral neuropathy (i.E., weakness, numbness, and pain typically in the hands and feet). Your doctor may advise you to take a vitamin B6 (pyridoxine) supplement during your treatment to help prevent peripheral neuropathy. Isoniazid may interact with foods containing histamine or tyramine (e.G., aged cheese, cured meats such as sausages and salami, fava beans, sauerkraut, soy sauce, beer, red wine, skipjack, tuna, mackerel, salmon), which can cause symptoms like headache, sweating, flushing, palpitations, dizziness, lightheadedness, or feeling faint. These foods should generally be avoided. It is important to seek immediate medical care if you experience any severe side effects or symptoms of liver damage such as fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, and/or yellowing of the skin or eyes. 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.