ADAP drugs: isoniazid

isoniazid (INH, Lanizid, Nydrazid)

Drug description

Isoniazid is used as a first-line treatment for tuberculosis (TB) in combination with other drugs for the treatment of active disease. Isoniazid is also used for prevention of TB in people who have been exposed to active disease but have no symptoms.

Side effects
Peripheral neuropathy is the most common side effect. Signs and symptoms of peripheral neuropathy are numbness, tingling, or an unusual sensation such as burning or prickling on the skin. Hepatitis is the most dangerous. Hepatitis is an inflammation of the liver. Signs and symptoms of hepatitis are yellow eyes and skin, nausea, vomiting, anorexia, dark urine, unusual tiredness, or weakness. Severe reactions may occur if you eat foods containing high concentrations of tyramine such as aged cheeses, avocados, bananas, beer, caffeinated beverages, chocolate, sausages, liver, overripe fruit, red wine, smoked or pickled fish, yeasts, and yogurt.

Dosage
Isoniazid comes in tablet, syrup and injectable forms. Isoniazid must be used cautiously if you have a history of liver damage or chronic alcoholism. While safety is not established, isoniazid has been used with ethambutol to treat TB in pregnant women without harm to the fetus. Dosage is 5-10 mg/kg/day (usually 300 mg) or 15 mg/kg 2-3 times per week. Take the drug on an empty stomach, at least 1-2 hours before meals.

How long it may take to work
Resolution of symptoms indicates treatment is effective. TB drugs may have to be taken for as long as 2 years.

Managing side effects
Isoniazid must be taken with vitamin B6 to reduce the incidence of peripheral neuropathy. Take 40-50 mg of vitamin B6 per day. If GI irritation becomes a problem, drug may be administered with food, although food decreases absorption of isoniazid. Antacids may also be taken 1 hour before administration. If you are being treated by injection, you may experience discomfort at the injection site. Massage site after administration and rotate injection sites. Notify your doctor if any signs or symptoms of peripheral neuropathy or hepatitis occur. Changes in visual clarity, eye pain, or blurred vision should be reported. Avoid the foods listed above. These can cause redness or itching of the skin, hot feeling, rapid or pounding heartbeat, sweating, chills, cold clammy feeling, headache, or lightheadedness. Notify your doctor if any of these reactions occur.

This information is specific to the use of this medication for HIV-related conditions. For additional information about this drug for other conditions, refer to: www.nursespdr.com/ and www.healthanswers.com/Library/library_fset.asp

The drug descriptions on these pages are intended for informational purposes only. The Network does not promote or endorse the use of any specific treatment for any health-related condition. The medications described here can only be dispensed by a licensed health care professional. The information may have changed since these pages were updated, though every effort is made to keep these pages current. Please contact The Network at (800) 734-7104 to make sure you have the most up-to-date information

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