Comparative Pharmacology
Head-to-head clinical analysis: ATARAX versus PROMETHAZINE WITH CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ATARAX versus PROMETHAZINE WITH CODEINE.
ATARAX vs PROMETHAZINE WITH CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydroxyzine is a piperazine derivative with antihistaminic (H1-receptor antagonist) and anticholinergic properties; also exhibits sedative, anxiolytic, and antiemetic effects due to suppression of activity in subcortical areas of the CNS.
Promethazine is a phenothiazine derivative that antagonizes histamine at H1 receptors, acting as a sedative and antiemetic. Codeine is an opioid agonist at mu-opioid receptors, producing analgesia and antitussive effects via central nervous system depression.
25 mg orally 3-4 times daily; maximum 100 mg per day. Also available as 50 mg intramuscular injection every 4-6 hours.
10-20 mg promethazine and 10-20 mg codeine (based on phosphate) orally every 4-6 hours as needed for cough; maximum daily codeine dose 120 mg.
None Documented
None Documented
Terminal elimination half-life is approximately 20-25 hours in healthy adults; may be prolonged in elderly, hepatic impairment, or renal insufficiency (up to 30-40 hours); steady-state achieved within 3-4 days.
Promethazine: 9-16 hours (mean 12 hours), clinically significant for sedation duration. Codeine: 2.5-4 hours (mean 3 hours), with active metabolite morphine 2-3 hours.
Primarily hepatic metabolism via CYP3A4 and CYP2D6; renal excretion of metabolites accounts for approximately 70-80% of the dose, with less than 1% excreted unchanged; fecal excretion is about 10-15%.
Promethazine: renal 70% as metabolites and unchanged drug, biliary/fecal 20-30%. Codeine: renal 90% (5-15% unchanged, rest as morphine and conjugates), fecal <10%.
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic