General pharmacology of 1-(2-ethoxyethyl)-2-(4-methyl-1-homopiperazinyl)benzimidazole difumarate. 2nd communication: Effects on the circulation and the other systems.

Effects of 1-(2-ethoxyethyl)-2(4-methyl-1-homopiperazinyl)benzimidazole difumarate (KB-2413) on the circulation and the other systems were compared with those of ketotifen and chlorpheniramine. 1. Among the effects on the circulation and the respiratory system, KB-2413 as well as ketotifen and chlorpheniramine transiently inhibited respiration at 3 mg/kg i.v. and slightly decreased blood pressure in dogs. KB-2413 slightly decreased heart rate in dogs, but ketotifen slightly increased it. 2. KB-2413 at 100 mg/kg p.o. slightly decreased the volume of gastric juice in rats and dose-dependently increased biliary secretion in rats in the dose range of 10-100 mg/kg i.d. On the other hand, ketotifen and chlorpheniramine decreased biliary secretion. 3. KB-2413 inhibited the spontaneous movements of various isolated smooth muscles at a high concentration of 10(-4) g/ml. 4. The autonomic system in cats and the motor nervous system in rats were not influenced by KB-2413 at 3 mg/kg i.v. 5. The blood clotting system, blood sugar level, urine volume and urinary electrolytes in rats were not affected by KB-2413 in the dose range of 10-100 mg/kg p.o. 6. KB-2413 inhibited carrageenin-induced rat paw edema at 100 mg/kg p.o. In conclusion, KB-2413 showed a less potent effect on the circulation and the other systems than ketotifen and chlorpheniramine, and no results suggested serious side effects of KB-2413.