Pharmacological studies on dl-glaucine phosphate as an antitussive

Antitussive effect, toxicity and other related pharmacological properties of dl-1,2,9,10-tetramethoxy-6a,alpha-aporphine phosphate (dl-glaucine phosphate, DL-832) were studied in comparison with those of codeine. Acute toxicity of DL-832 in mice was 2/5 to 7/10 of that of codeine for any routes of i.v., i.p., s.c. and p.o. The antitussive effect as tested by "coughing dog and cat" methods and Domenjoz's method in cats was 1/5 to 4/5 that of codeine, according to the routes administered. Safety margin in antitussive effect was similar to or less than that of codeine. Differing from codeine, levallorphan exerted no influence on the antitussive effect of DL-832. In vitro, DL-832 exerted moderate relaxant actions on normal tone and on contractions induced by histamine and acetylcholine of tracheal muscle. In vivo, it showed a moderate relaxant effect on histamine-induced bronchial constriction. The decrease in the volume of respiratory tract fluid caused by DL-832 was smaller than that by codeine. DL-832 slightly reduced the transportation rate of intratracheal foreign body, although to much lesser extent as compared to codeine. On respiration, blood pressure and heart rate, DL-832 showed depressant effects and moreover it caused changes in ECG. However, all of these effects were similar to and a little weaker than those observed with codeine. DL-832 prolonged hexobarbital sleeping time significantly. Neither analgesic nor anticonvulsant effect was observed. When given in larger doses, DL-832 inhibited intestinal transportation in vivo, although this effect was much weaker than that of codeine. DL-832 showed slight local anesthetic effect.