ABSOROPTION REDUCED BY FOOD. ANTACIDS REDUCE RATE OF ABSORPTION & CMAX WAS REDUCED BY 24%. INCREASES ABSORPTION OF DIGOXIN AND CYCLOSPORINE. CONCURRENT USE OF MACROLIDES AND THEOPHYLLINE HAS BEEN ASSOCIATED WITH INCREASES IN THE SERUM CONCENTRATIONS OF THEOPHYLLINE. CONCURRENT USE OF MACROLIDES AND WARFARIN IN CLINICAL PRACTICE HAS BEEN ASSOCIATED WITH INCREASED ANTICOAGULANT EFFECTS. DRUGS METABOLIZED BY THE CYTOCHROME P450 SYSTEM- -ELEVATIONS OF SERUM
CARBAMAZEPINE, TERFENADINE, CYCLOSPORINE, HEXOBARBITAL, AND PHENYTOIN LEVELS.
DIGOXIN--ELEVATED DIGOXIN LEVELS. ERGOTAMINE OR DIHYDROERGOTAMINE--ACUTE ERGOT TOXICITY CHARACTERIZED BY SEVERE PERIPHERAL VASOSPASM AND DYSESTHESIA. TRIAZOLAM--DECREASE THE CLEARANCE OF TRIAZOLAM AND THUS MAY INCREASE THE PHARMACOLOGIC EFFECT OF TRIAZOLAM. MAY POTENTIATE ACTION OF CARBAMAZEPINE, CYCLOSPORIN, THEOPHYLLINE, WARFARIN, HEXABARBITAL, TRIAZOLAM(BENZODIAZEPINES) . INCREASES SERUM DIGOXIN LEVELS, REDUCES THERAPEUTIC EFFECT OF PENICILLINS, TERFENADINE AND ASTEMIZOLE. INCREASES THE RISK OF THE ADVERSE EFFECT ON THE HEART. ERGOTAMINE OR DIHYDROERGOTAMINE HAS BEEN ASSOCIATED IN SOME PATIENTS WITH ACUTE ERGOT TOXICITY CHARACTERIZED BY SEVERE PERIPHERAL VASOSPASM AND DYSESTHESIA. PATIENTS RECEIVING CONCOMITANT LOVASTATIN AND ERYTHROMYCIN SHOULD BE CAREFULLY MONITORED; CASES OF RHABDOMYOLYSIS HAVE BEEN REPORTED IN SERIOUSLY ILL PATIENTS. ERYTHROMYCIN SHOULD NOT BE GIVEN WITH OTHER DRUGS THAT PROLONG THE QT INTERVAL DUE TO THE INCREASED RISK OF PRECIPITATING VENTRICULAR ARRHYTHMIAS. THESE DRUGS ARE AMIODARONE, DISOPYRAMIDE, PROCAINAMIDE, OR QUINIDINE, PHENOTHIAZINE ANTIPSYCHOTICS, TRICYCLIC ANTIDEPRESSANTS, ANTIHISTAMINES, ASTEMIZOLE AND TERFENADINE, HALOFANTRINE, PENTAMIDINE, SULTOPRIDE, OR VINCAMINE AND DIURETICS