TABLE 4.
Potential clinically significant drug interactions involving erythromycin, clarithromycin and azithromycin
| Effect when administered with macrolide indicated | |||
|---|---|---|---|
| Interacting drug | Erythromycin | Clarithromycin | Azithromycin |
| Theophylline and related drugs | Increased serum theophylline level with possible toxicity | Increased serum theophylline level with possible toxicity | No interaction observed but caution advised |
| Carbamazepine | Increased serum carbamazepine level with possible toxicity | Increased serum carbamazepine level with possible toxicity | No interaction reported |
| Cisapride (no longer marketed in Canada) | Increased serum cisapride level with possible cardiotoxicity (QT prolongation) | Increased serum cisapride level with possible cardiotoxicity (QT prolongation) | No interaction reported |
| Cyclosporine, tacrolimus | Increased serum immunosuppressant level with possible toxicity | Increased serum immunosuppressant level with possible toxicity | No interaction reported |
| Astemizole, terfenadine (no longer marketed in Canada) | Increased serum level of antihistamine leading to possible cardiotoxicity (QT prolongation) | Increased level on antihistamine leading to possible cardiotoxicity (QT prolongation) | No interaction reported |
| Alprazolam, diazepam, midazolam, triazolam | Increased serum level of benzodiazepines that undergo oxidative metabolism with possible toxicity | No interaction reported | No interaction reported |
| Buspirone | Increased serum buspirone level with possible toxicity | No interaction observed but caution advised | No interaction reported |
| Ergot alkaloids (including bromocriptine) | Increased risk of peripheral ischemia | Increased risk of peripheral ischemia | No interaction reported |
| Lovastatin | Possible severe myopathy or rhabdomyolysis; caution advised with all 3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors | No interaction observed but caution advised | No interaction observed but caution advised |
| Rifabutin, rifampin | Possible decrease in antimicrobial effects | Possible decrease in antimicrobial effects | No interaction reported |
| Disopyramide | Increased serum disopyramide level | Increased serum disopyramide level with possible toxicity | No interaction reported |
| Digoxin | Increased serum digoxin level with possible toxicity | Increased serum digoxin level with possible toxicity | No interaction reported |
| Warfarin | Reduction in warfarin clearance leading to potentiation of anticoagulant effect | Reduction in warfarin clearance leading to potentiation of anticoagulant effect | No interaction reported |
Data from reference 96