Nydrazid Disease Interactions

The use of isoniazid is contraindicated in patients with a history of hepatic injury due to this drug and acute liver disease of any etiology. Caution is advised when using the drug in patients with chronic liver disease or a history of alcoholism. This drug has been associated with severe and sometimes fatal hepatitis, which may occur even after many months of therapy. In a US Public Health Service Surveillance Study of 13,838 persons taking isoniazid, there were 8 deaths among 174 cases of hepatitis. Epidemiologic studies indicate an increased incidence with increasing age, alcohol use, and female gender. As a precautionary measure, routine monitoring of serum transaminases (SGOT, SGPT) and bilirubin may be considered, although a transient and harmless increase in serum transaminase reportedly occurs in 10% to 20% of patients, usually in the first 3 months of therapy. Patients should be advised to promptly discontinue isoniazid therapy and seek medical attention if they experience signs or symptoms suggestive of liver damage such as fever, rash, anorexia, nausea, vomiting, fatigue, right upper quadrant pain, dark urine, and jaundice. Reinstitution of the drug should occur only after symptoms and laboratory abnormalities resolve, with low and gradually increasing dosages.

Isoniazid commonly causes dose-related peripheral neuropathy, which results from the depletion of pyridoxine in the presence of the drug. The neuropathy is usually preceded by paraesthesia's of the feet and hands. Therapy with isoniazid should be administered cautiously in patients with pre-existing peripheral neuropathy or risk factors for developing the condition, such as malnutrition, diabetes and alcoholism. Careful monitoring is recommended on these patients. Pyridoxine (vitamin B6) at a dosage of 10 to 50 mg/day may prevent or attenuate isoniazid-related peripheral neuropathy and is recommended for these patients.

Isoniazid is substantially removed by hemodialysis and should be administered after dialysis.

Caution and close monitoring is advised when using isoniazid in patients with HIV seropositive patients. Patients with pulmonary tuberculosis and HIV infection may have problems with malabsorption. Screening of antimycobacterial drug levels, especially in patients with advanced HIV disease, may be necessary to prevent the emergence of multi-drug resistant tuberculosis.

Isoniazid may cause cerebellar syndrome in patients with chronic kidney disease. Patients with end-stage renal disease have been reported to have an increased risk of developing tuberculosis. Careful monitoring is recommended if this drug is used in patients with severe renal dysfunction. Dosage adjustments in renal impairment are generally not necessary except in slow acetylators with a creatinine clearance below 10 mL/min. Approximately 50% of Blacks and Caucasians are slow acetylators, and most Eskimos and Asians are rapid acetylators.