Although no clinically significant effects were noted when
clarithromycin was given with
ritonavir, the
clarithromycin became more dependent on
renal clearance and so it was suggested that there may be a significant interaction in patients with
renal failure.
The manufacturers of
ritonavir and
clarithromycin suggest that no dosage reductions should be needed in those with normal
renal function, but they recommend reductions for those with reduced
creatinine clearances. They also advise avoidance of
clarithromycin dosages exceeding 1 g daily.