Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus X TROZINE L A.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus X TROZINE L A.
PROMETHAZINE W/ CODEINE vs X-TROZINE L.A.
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Codeine is a prodrug converted to morphine, a mu-opioid receptor agonist, which inhibits nociceptive transmission; promethazine is a phenothiazine derivative with H1-receptor antagonism, anticholinergic, and antiemetic effects.
X-TROZINE L.A. is a piperazine derivative that acts as a centrally acting alpha-2 adrenergic agonist, reducing sympathetic outflow from the brainstem, leading to decreased peripheral vascular resistance and lowered blood pressure.
10 mL (1 mg codeine, 6.25 mg promethazine per 5 mL) orally every 4-6 hours as needed for cough. Maximum: 60 mL per day. Do not exceed 5 days.
250 mg orally once daily. May be increased to 500 mg once daily if needed.
None Documented
None Documented
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
12-15 hours; prolonged in renal impairment (up to 30 hours in CrCl <30 mL/min).
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Primarily renal (70-80% as unchanged drug), with 20-30% fecal via biliary excretion.
Category A/B
Category C
Antihistamine / Antiemetic
Antihistamine