The risk of hypotension following co-prescription of macrolide antibiotics and calcium-channel blockers Full Text
Canadian Medical Association Journal, 02/24/2011
Wright AJ et al. - In older patients receiving a calcium-channel blocker, use of erythromycin or clarithromycin was associated with an increased risk of hypotension or shock requiring admission to hospital. Thus, preferential use of azithromycin should be considered when a macrolide antibiotic is required for patients already receiving a calcium-channel blocker.
Methods- The study was conducted on 7100 patients
- The study involved people aged 66 years and older who had been prescribed a calcium-channel blocker
- Those patients were also included those who had been admitted to hospital for the treatment of hypotension or shock
- Erythromycin (the strongest inhibitor of cytochrome P450 3A4) was most strongly associated with hypotension (odds ratio [OR] 5.8, 95% confidence interval [CI] 2.3–15.0), followed by clarithromycin (OR 3.7, 95% CI 2.3–6.1).
- Azithromycin, which does not inhibit cytochrome P450 3A4, was not associated with an increased risk of hypotension (OR 1.5, 95% CI 0.8–2.8)
- Authors found similar results in a stratified analysis of patients who received only dihydropyridine calcium-channel blockers.
