Background: Macrolide antibiotics inhibit the cytochrome p450 enzyme system, which metabolizes calcium-channel blockers. This may result in a clinically significant interaction, causing hypotension in patients co-prescribed these two drugs. Since these drugs are frequently used in the haemodialysis population, we studied the effect of their co-prescription on actual blood pressure.
Methods: A retrospective chart review of all haemodialysis patients was conducted to identify patients co-prescribed a macrolide and a dihydropyridine calcium-channel blocker. Blood pressure measurements before and during the macrolide co-prescription were abstracted and compared using a student's t test.
Results: We identified 154 haemodialysis patients concurrently prescribed a macrolide antibiotic and a dihydropyridine calcium-channel blocker. There was no significant difference in episodes of intra-dialytic hypotension or actual blood pressure measurements in the period before macrolide co-prescription and the period during macrolide co-prescription.
Conclusion: In contrast to hospitalized patients receiving dihydropyridine calcium-channel blockers, concurrent administration of a macrolide antibiotic for infection did not result in hypotension in haemodialysis outpatients. Further research should be undertaken before a change in clinical practice against their co-prescription is considered.