Interaction of antacids with antiarrhythmics. V. Effect of aluminium hydroxide and magnesium oxide on the bioavailability of quinidine, procainamide and propranolol in dogs

The influence of aluminium hydroxide and magnesium oxide on the oral bioavailability of quinidine, procainamide and propranolol in the dog was investigated. The administration of aluminium hydroxide with a quinidine sulfate capsule causes a significant decrease of maximal plasma concentration (Cpmax) and a shift in tmax (time to reach Cpmax). The area under the curve is not significantly decreased. Administration of magnesium oxide together with a quinidine sulfate capsule or a sustained-release preparation of quinidine bisulfate causes a significant decrease of both Cpmax and the area under the curve. A shift of tmax was observed for the conventional preparation only. The administration of aluminium hydroxide with procainamide hydrochloride diminishes only Cpmax in a significant way. Administration of magnesium oxide together with procainamide hydrochloride has no influence on the different parameters. Administration of aluminium hydroxide or magnesium oxide with propranolol hydrochloride has a significant negative influence on both the Cpmax and the area under the curve.