Influence of Diphenhydramine on Blood Pressure Response to Epinephrine in the Dog under Adrenergic Blockade

Abstract

Conclusion Diphenhydramine was found to convert the vasodepressor effect of epinephrine and arterenol in the dog under adrenergic blockade with SY-28 to a vasopressor effect. The para-methyl substituted derivative of diphenhydramine as well as cocaine, tripelennamine, pyranisamine maleate, dtubocurarine, dibutoline and ergotamine can produce the same effect. Atropine (anticholinergic), papaverine (antispasmodic) and 2-N-propoxy-4, 6-diamino-s-triazine (antihistaminic) are ineffective. An inhibition of the vasodepressor mechanism is suggested as a possible made of action of these compounds on the reversal of the vasodepressor response and the potentiation of the vasopressor response to epinephrine and arterenol.