[Pharmacological properties of lopramine]

Pharmacological properties of LOP were compared with those of imipramine(IMP). LOP had little or no effect on electroconvulsive shock and chemoconvulsions in mice, conditioned avoidance response in rats, pain threshold in mice and rats and body temperature in rabbits. LOP, unlike IMP, showed relatively weak effects on general behavior in mice, spontaneous EEG in cats and spontaneous motor activity in mice. LOP prevented oxotremorine-induced hypothermia but not tremor, while IMP antagonized both the responses in mice. In anesthetized dogs, LOP caused a respiratory stimulation and a fall in blood pressure, left ventribular pressure and left ventricular dp/dt without a noticeable effect on heart rate. LOP was less potent than IMP in the depressor and cardiodepressing effects, antispasmogenic activity and in antagonizing the depressor response to acetylcholine. LOP, like IMP, potentiated pressor response to norepinephrine and reduced that to tyramine in anesthetized dogs, but neither antidepressant produced norepinephrine potentiation in isolated guinea-pig vas deferens. Both drugs inhibited spontaneous motility of the jejunum without reducing the gastric motility in anesthetized dogs. These results indicate that, compared with IMP, LOP is characterized by weak general pharmacological activities.