It is about equal to codeine in depressing the cough reflex. In therapeutic dosage dextromethorphan does not inhibit ciliary activity. Promethazine is an H 1 receptor blocking agent. In addition ...

Background and aims: We have recently shown that Dextromethorphan is neuroprotective ... if administered 1 hour after injury. The low dose of 0.1μg/g body weight was as effective as the high ...