What is Isoniazid: Uses, Warnings & Interactions

Your doctor will tell you how much medicine to take and how often. It is very important to take this medicine on a regular schedule.

You may need to take isoniazid for several weeks or months. Keep taking it even if you have no symptoms. Your doctor will tell you when you can stop taking it.

Take on an empty stomach (1 hour before or 2 hours after a meal). May be taken with food to avoid stomach upset.

Shake the oral liquid well just before each use. Measure the dose using a marked measuring spoon or medicine cup.

Your doctor will tell you how much medicine to take and how often. It is very important to take this medicine on a regular schedule.

You may need to take isoniazid for several weeks or months. Keep taking it even if you have no symptoms. Your doctor will tell you when you can stop taking it.

Take on an empty stomach (1 hour before or 2 hours after a meal). May be taken with food to avoid stomach upset.

Shake the oral liquid well just before each use. Measure the dose using a marked measuring spoon or medicine cup.

Take the missed dose as soon as possible.

Skip the missed dose if it is almost time for your next regular dose.

You should not use two doses at the same time.

You should not use this medicine if you have ever had an allergic reaction to isoniazid or reactions such as fever, chills, or arthritis from taking this medicine. You should not use isoniazid if you have liver damage from taking it before, or if you have severe liver disease of any type.

If you are pregnant or breastfeeding, talk to your doctor before taking this medicine.

Check with your doctor before taking if you have kidney or liver disease, or if you are being treated for seizures.

Isoniazid can cause liver problems. It is very important that you see your doctor on a regular schedule and have blood tests done as ordered.

Isoniazid can affect the results of some urine sugar tests. If you have diabetes do not change your medicine or diet unless you have checked with your doctor.

If you notice tingling, numbness, or pain in your hands or feet, contact your doctor.

Fever

Do not drink alcohol while taking isoniazid.

Make sure your doctor knows if you are taking blood thinners (such as Coumadin®), birth control pills, Dilantin®, or Antabuse®.

If you take antacids (such as Mylanta®, Maalox®, or Amphojel®), wait at least 1 hour after taking them before taking your isoniazid dose.

Foods such as cheese (Swiss, Cheshire, or Gruyere) or fish (tuna or skipjack) may cause headache, flushing, pounding heartbeat, sweating, dizziness, chills, or diarrhea. If you have these symptoms, call your doctor.

If you notice tingling, numbness, or pain in your hands or feet, contact your doctor.