In therapeutic dosage dextromethorphan does not inhibit ciliary activity. Promethazine is an H 1 receptor blocking agent. In addition to its antihistaminic action, it provides clinically useful ...

and the three suppository treatments were comparable in terms of dose- normalized C max. [a] Phenergan 12.5-mg rectal suppository, Wyeth-Ayerst Laboratories, Radnor, PA, lot 9940524. [b] Phenergan ...