Isoniazid

ISONIAZID – ORAL (eye-so-NYE-uh-zid)

COMMON BRAND NAME(S): Isotamine, Niazid

WARNING: This medication has caused severe, even fatal, liver problems (e.g., hepatitis). Liver problems increase with age and with daily use of alcohol. Hepatitis can develop with use of this drug at any time during treatment. Stop using this medication and notify your doctor immediately if you develop unusual fatigue, weakness, loss of appetite, nausea, vomiting, dark urine, yellowing of the eyes or skin, or stomach or abdominal pain. Your doctor may decide to slowly restart isoniazid after these symptoms disappear and lab tests return to normal. People with active (acute) liver problems should not use this medication for preventative treatment until after the liver problems have stopped. Your doctor will monitor your liver function tests at least every month to discuss your progress.

USES: This medication is used to prevent and treat tuberculosis.

HOW TO TAKE THIS MEDICATION: This medication is best taken on an empty stomach 1 hour before or 2 hours after meals. But it may be taken with food or milk if stomach upset occurs. Take as directed. Do not stop taking this medication without your doctor’s approval. Stopping therapy early may result in ineffective treatment and the infection could recur. Vitamin B6 (pyridoxine) supplements may be prescribed in addition to this medication to prevent numbness and tingling.

SIDE EFFECTS: May cause stomach upset, heartburn, nausea or dizziness. These effects should disappear as your body adjusts to the medication. If these effects persist or become bothersome, inform your doctor. Notify your doctor if you experience:

PRECAUTIONS: Tell your doctor your medical history, especially of: kidney or liver problems, diabetes, alcohol use, previous treatment for tuberculosis, any allergies. Alcohol can reduce the effectiveness of isoniazid and increase side effects. Minimize alcohol consumption. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. Isoniazid is excreted into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Tell your doctor of all medications you may use (both prescription and nonprescription) especially of: aluminum-containing antacids, disulfiram, phenytoin, rifampin, carbamazepine. This drug may interfere with the effectiveness of birth control pills. Discuss using other methods of birth control with your doctor. Isoniazid can cause false positive results in diabetics using Clinitest to test their urine. Consult your doctor or pharmacist for recommendations. Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include nausea; vomiting; dizziness; slurring of speech; blurred vision; numbness, tingling, or burning of your arms, hands, legs, or feet; joint pain; hallucinations; and loss of consciousness.

NOTES: Periodic eye tests may be done while you are taking this medication.

MISSED DOSE: If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not ‘double-up’ the dose to catch up.

STORAGE: Store at room temperature away from moisture and sunlight. Do not store in the bathroom. Do not freeze liquid forms of this medicine.