Drug to which infection is resistant	Treatment regimen	Duration of therapy
Isoniazid (INH)	Rifampin	6 to 9 months
	Ethambutol
	Pyrazinamide
Rifampin (Rifadin)	Isoniazid	18 months
	Ethambutol
Ethambutol (Myambutol), pyrazinamide or streptomycin	Isoniazid	6 to 9 months
	Rifampin