A Comparative Study of the Spasmolytic Activities of Octaverine, Perparine and Papaverine

Abstract

Summary A comparative study has been made of the toxicities and spasmolytic activities of papaverine and 2 synthetic analogues, octaverine and perparine. Octaverine and perparine have about one-half of the acute toxicity of papaverine, as shown by the combined LD50 figures, the minimum convulsive doses and the minimum doses required to diminish reflexes and establish lateral decubitus in mice. Octaverine is 4 times, and perparine twice, as active as papaverine in suppressing the spontaneous contractions of rat uterus. All 3 alkaloids have the same activity against barium chloride-induced spasm in isolated guinea-pig ileum. Octaverine and papaverine possess the same activity against spasm provoked by histamine or by pilocarpine; perparine has one-half of the activity of papaverine against histamine spasm and double the activity of papaverine against pilocarpine spasm. 5 Orally administerd papaverine has no action against histamine-induced bronchospasm in guinea-pigs; both octaverine and perparine possess a definite although small activity under comparable conditions.