Disopyramide Antacids

The antiemetics and antivertigo drug may have additive effects when used with alcohol and other CNS depressants such as sedatives, hypnotics, antianxiety drugp, opiates, and antidepressants. There may be additive anticholinergic effects (see Chap. 25) when administered with drag s that have anticholinergic activity such as the antihistamines, antidepressants, pheno-thiazines, and disopyramide The antacids decrease absorption of the antiemetics. 

Erythromycin Drugs that may be affected by erythromycin include alfentanil, anticoagulants, benzodiazepines, buspirone, carbamazepine, cisapride, cyclosporine, digoxin, disopyramide, ergot alkaloids, felodipine, fluoroquinolones, HMG-CoA reductase inhibitors, lincosamides, methylprednisolone, penicillins, and theophyllines. Drugs that may affect erythromycin include antacids, pimozide, rifamycins, and theophyllines. 

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... 

A single 11-g dose of an aluminium phosphate antacid had no statistically significant effect on the pharmacokinetics of a single 200-mg oral dose of disopyramide in 10 patients. However the antacid appeared to reduce the absorption of disopyramide to some extent in individual subjects. The clinical importance of this interaction is uncertain, but probably small. 

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