Erythromycin Aminophylline

Aminophylline Aminophylline should not be mixed with acidic drugs, as it becomes precipitated if the pH of the final solution falls below pH 8. Mixture with glucose may increase the pH above 10 where proteins, such as insulin and erythromycin, are unstable. Some drugs that are incompatible with aminophylline include amiodarone, benzylpenicillin potassium, cisatracurium, ceftazidime, ceftriaxone, dobutamine, tetracycline hydrochloride, verapamil hydrochloride, warfarin sodium, and vitamin B and C injection. Alcohol-free theophylline should be stored in amber-colored containers maximum care must be taken to protect it against exposure to light.92-94... 

Fatal aminophylline toxicity has been described, precipitated by the concomitant administration of erythromycin (64). 

These cases of interactions of aminophylline with macro-lide antibiotics illustrate that serious, even fatal, adverse effects can occur when possible interactions are not considered. In both cases, experienced physicians prescribed appropriate antimicrobial drugs, but omitted to consider the possibility of interactions with aminophylline, and failed to reduce the dose of aminophyUme or to measure theophylline concentrations. In the first case the development of tachycardia, hypokalemia, acidosis, vomiting, and convulsions can be explained on the basis of theophylline toxicity caused by ciprofloxacin, while in the second the anxiety, tremor, and cardiac arrests could all have resulted from an interaction of aminophylline and erythromycin. These cases add to an extensive literature that emphasizes the potential for interaction between aminophylline and drugs metabolized by CYP1A2. 

Andrews PA. Interactions with ciprofloxacin and erythromycin leading to aminophylline toxicity. Nephrol Dial Transplant I998 I3(4) I006-8. 

Clinically important, potentially hazardous interactions with aminophylline, amiodarone, antacids, antineoplastics, arsenic, bepridil, bismuth, bismuth subsalicylate, bretylium, calcium salts, cocoa, didanosine, disopyramide, duloxetine, erythromycin, iron, magnesium salts, meptazinol, methylxanthines, NSAIDs, phenothiazines, procainamide, quinidine, rasagiline, sotalol, sucralfate, tizanidine, tricyclic antidepressants, zinc... 

Clinically important, potentially hazardous interactions with aminophylline, aspirin, carbamazepine, clarithromycin, cyclosporine, daclizumab, erythromycin, itraconazole, ketoconazole, live vaccines, oral contraceptives, phenobarbital, rifampicin, rifampin, troleandomycin, warfarin... 

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