Potentiation of antitussive effect of codeine by some 1-dimethoxyphenyl-3-alkylaminobutanols in guinea pigs.

Newly synthesized 1-(2',5'-dimethoxyphenyl)-1-n-butyl-3-diethylaminobutanol (compd. 4) and its analogs enhanced the antitussive effect of codeine and morphine as tested on the cough induced by mechanical stimulation of the trachea in guinea pigs. This effect was illustrated to be a potentiation on the Gaddum's diagram. The following parameters were affected little or to a small extent: 1. analgesic effect of codeine and morphine in guinea pigs and mice, 2. duration of anesthesia induced by hexobarbital in mice, 3. respiratory depression caused by codeine in guinea pigs, and 4. LD50 of codeine in guinea pigs and mice. Explorations of the mechanism of potentiating action suggested some peripheral mechanism, but the exact one remained to be elucidated.