COMPARISON OF THE ANTITUSSIVE EFFECTS OF CODEINE PHOSPHATE 20 MG, DEXTROMETHORPHAN 30 MG AND NOSCAPINE 30 MG USING CITRIC ACID-INDUCED COUGH IN NORMAL SUBJECTS

1. Protection by codeine 20 mg, dextromethorphan 30 mg, noscapine 30 mg, and placebo against citric acid-induced cough was determined in eighteen healthy subjects. 2. Drug differences occurred at 2 1/2 h following ingestion of the drugs but not at 1 1/4 h. 3. Only codeine 20 mg had a greater antitussive action than placebo, but dextromethorphan 30 mg also did not differ from codeine 20 mg. 4. This technique may offer a useful screening test for the activity of new potential antitussive compounds in man. © 1979 Springer-Verlag.