Sublingual absorption of the quaternary ammonium antiarrhythmic agent, UM-272

UM-272 (N,N-dimethylpropranolol), a quaternary antiarrhythmic agent, was administered sublingually to dogs with ouabain-induced ventricular tachycardias. Both anti-arrhythmic efficacy and bioavailability were compared to oral drug. Sublingual UM-272 converted ventricular tachycardia to sinus rhythm in all 5 dogs. The area under the plasma concentration time curve at 90 min was 4-12 times greater than for oral drug, suggesting the existence of an absorption-limiting process in the intestine, and providing an alternate form of administration for quaternary drugs.