Pharmacology of some synthetic tetrahydrocannabinols.

DMHP (1-hydroxy-3-1', 2'-dimethylheptyl-6,6,9-trimethyl 7,8,9,10-tetrahydro-6-dibenzopyran or in brief dimethyl heptyl pyran, EA 1476) is a synthetic analog of delta 9-tetrahydrocannabinol (delta 9-THC). Both DMHP and its acetate, DMHPA (EA 2233) produce varying degrees of physical and mental incapacitation. Both compounds elicit orthostatic hypotension at dose levels far below those required to produce mild mental incapacitation. Compared with delta 9-THC, DMHP has clearly more potent and prolonged hypotensive action, but much less psychological effect. The potencies of DMHP and DMHPA are more or less similar, but the acetate derivative is more stable against the degrading effects of light and air. Like DMHP, DMHPA consists of eight isomers which vary in their potency. Accordingly, depending on the proportion of the isomers, the racemic mixtures show variability in their potencies. The isomers 2 and 4 have been shown to be more potent than the other isomers.