Ketoconazole increases the AUC of
telithromycin 2-fold. Because
ritonavir is a more potent
enzyme inhibitor than
ketoconazole the manufacturers predict that the exposure to
telithromycin may be greater than 2-fold in the presence of
ritonavir.
The manufacturers advise caution on concurrent use. Monitor for
telithromycin adverse effects (such as diarrhoea, dizziness and headache).