one 25-mg suppository, one 50-mg suppository, or 50 mg (10 mL) of promethazine oral syrup. Blood samples were collected before each dose and at intervals from 0.5 to 48 hours afterward.

Promethazine concentration-versus-time curves for two 12.5-mg promethazine suppositories (A), one 25-mg promethazine suppository ... oral syrup (closed circles). Dose-normalized promethazine ...

Promethazine HCl 12.5mg ... Perioperative nausea & vomiting: 25mg; may give additional doses of 12.5–25mg at 4–6hr intervals. <2yrs: see Contraindications. Motion sickness: ≥2yrs: 12.5 ...