Ethionamide
Adverse Effect: hepatotoxicity Clinical Management: Combined pyrazinamide-ethionamide therapy should only be administered to patients found to have normal baseline liver function. Regular liver function tests should be performed during use of this combination of agents. Patients with diabetes mellitus are more likely to experience hepatotoxicity and have more difficulty with diabetic management; these patients need close monitoring. Ethionamide should be withdrawn if significant alterations in liver tests are observed.
Phenytoin
Adverse Effect: increased phenytoin serum concentrations and subsequent phenytoin toxicity (ataxia, hyperreflexia, nystagmus, tremor) Clinical Management: Caution should be used when pyrazinamide is administered to phenytoin-treated patients. Monitor for CNS adverse effects (ataxia, hyperreflexia, nystagmus, tremor) with measurement of phenytoin serum concentrations as needed.
Probenecid
Adverse Effect: increased serum uric acid levels and worsening of gout symptoms Clinical Management: Monitor serum uric acid levels and symptoms of gout; adjust probenecid dose accordingly.
Zidovudine
Adverse Effect: decreased efficacy of pyrazinamide Clinical Management: Monitor the pyrazinamide serum levels in patients receiving concurrent zidovudine therapy. Alternative antituberculosis treatment may need to be considered |