Dihydrocodeine

DIHYDROCODEINE and dihydroisocodeine are hydrogenated derivatives of codeine and isocodeine. Eddy and Small1 investigated the toxicity and analgesic potency of the two isomers in animals. As with codeine, both drugs in mice and rabbits produced initial Central-nervous-system depression. The doses required were smaller than those for codeine. A further increase in the dosage of dihydrocodeine resulted in convulsions. Dihydroisocodeine in large dosage did not produce convulsions at all. Analgesic potency was measured in cats by the tail-pressure method. Both dihydroisocodeine and dihydrocodeine produced greater analgesia than codeine, milligram for milligram. These agents were thus candidates for clinical trial.In the . . .