Theophylline levels should be monitored in patients who are administered with clarithromycin, as increased serum theophylline levels and potential theophylline toxicity may occur during concomitant administration of the 2 drugs.
The use of clarithromycin in patients receiving warfarin may result in a potentiation of the effects of warfarin. Prothrombin time should be frequently monitored in these patients.
The effects of digoxin may be potentiated with concomitant administration of clarithromycin.
Simultaneous oral administration of clarithromycin tablets and zidovudine to HIV-infected adult patients may result in decreased steady-state zidovudine concentrations.