Erimycin For Suspension Drug Interactions

1. Antifungal agent: Concomitant use of Erythromycin with these drugs that inhibit CYP3A isoenzyme (i.e., fluconazole, ketoconazole, itraconazole) increases Erythromycin plasma concentration. The result of this effect increases risk of QT prolongation (a dose-associated effect of Erythromycin) and serious ventricular arrhythmias. Should be avoid this combination.
2. Astemizole and Terfenadine: Erythromycin may interaction with astemizole and terfenadine, resulting in potentially serious adverse cardiovascular effects (prolongation of the QT interval, ventricular tachycardia, torsades de pointes). Coadministration is contraindication.
3. Calcium-channel blocking agents: Concomitant use with diltiazem or verapamil; presumably increased serum concentrations of both drugs resulting in an increased risk of QT prolongation (a dose-associated effect of Erythromycin) and serious ventricular arrhythmias or cardiotoxicity and hypotension. Should be avoid this combination.
4. Cisapride: Erythromycin inhibits cytochrome P450 enzymes that metabolize cisapride (CYP3A4) and increase plasma cisapride concentrations, which may increase the potential for serious adverse effects (e.g., life-threatening cardiac arrhythmias). Coadministration is contraindication.
5. Digoxin: Concomitant use of Erythromycin and digoxin has resulted in increased serum concentration of digoxin; toxicity may occur. Monitor digoxin levels and adjust dose as needed.
6. Carbamazepine: Concomitant use of Erythromycin and carbamazepine has resulted in increased serum concentration of carbamazepine and subsequent signs of carbamazepine toxicity (e.g. ataxia, dizziness, drowsiness, and vomiting). Should be avoid this combination.
7. Cyclosporine: Concomitant use of Erythromycin and cyclosporine has resulted in increased serum concentration of cyclosporine subsequent signs of cyclosporine toxicity (e.g. nephrotoxicity, neurotoxicity). Monitor cyclosporine levels and serum creatinine; adjust dose as needed.
8. Ergot alkaloids: Concomitant use of Erythromycin and ergotamine may induce ischemic reactions, peripheral vasospasm and dysesthesia. Coadministration is contraindication.
9. Benzodiazepines (i.e. alprazolam, diazepam, midazolam, triazolam): Coadministration may decrease the metabolism of certain benzodiazepines resulting in increased CNS depression and prolonged sedation. Use with caution.
10. Theophylline: Concomitant use of Erythromycin and theophylline may decrease clearance of theophylline, elevate serum concentrations of theophylline, and a prolong serum half-life of the bronchodilator. Monitor theophylline levels.
11. Warfarin: Concomitant use of Erythromycin and warfarin may increase the anticoagulant effect of warfarin. Bleeding has occurred. Increased anticoagulant effect may be more pronounced in geriatric patients. Monitor anticoagulant parameters and adjust the warfarin dose as needed.