Renal Insufficiency: The disposition of rifabutin (300 mg) was studied in 18 patients with varying degrees of renal function. Area under plasma concentration time curve (AUC) increased by about 71% in patients with severe renal insufficiency (creatinine clearance below 30 mL/min) compared to patients with creatinine clearance (Crcl) between 61-74 mL/min. In patients with mild to moderate renal insufficiency (Crcl between 30-61 mL/min), the AUC increased by about 41%.
A reduction in the dosage of rifabutin is recommended for patients with Crcl <30 mL/min.
Warnings: Severe renal impairment (creatinine clearance below 30 mL/min) requires a dosage reduction of 50%. Mild to moderate renal impairment does not require any dosage adjustment.
DOSAGE AND ADMINISTRATION: It is recommended that MYCOBUTIN Capsules be administered at a dose of 300 mg once daily. For those patients with propensity to nausea, vomiting, or other gastrointestinal upset, administration of MYCOBUTIN at doses of 150 mg twice daily taken with food may be useful. For patients with severe renal impairment (creatinine clearance less than 30 mL/min), the dose of MYCOBUTIN should be reduced by 50%.
No dosage adjustment is required for patients with mild to moderate renal impairment.