Drug Intolerance
For patients who cannot tolerate rifampin, alternative regimens include 9-12 months of isoniazid, ethambutol and pyrazinamide, with or without a fluoroquinolone (usually levofloxacin, moxifloxacin, or gatifloxacin); 18 months of isoniazid plus ethambutol has also been given. Rifabutin has been substituted for rifampin in standard regimens for some patients who could not take rifampin because of drug interactions. Patients who cannot take pyrazinamide in the initital phase of treatment should receive continuation therapy with isoniazid and rifampin for a total of 7 months.