Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus ZUPLENZ.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE W CODEINE versus ZUPLENZ.
PROMETHAZINE W/ CODEINE vs ZUPLENZ
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.
Competitive serotonin 5-HT3 receptor antagonist; acts centrally on the chemoreceptor trigger zone and peripherally on GI vagal nerve terminals to inhibit emesis.
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.
8 mg administered intraorally as a single dose 1 hour before chemotherapy; may repeat once if vomiting occurs within 30 minutes after initial dose.
None Documented
None Documented
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Terminal elimination half-life 3.5 hours; in hepatic impairment increases to 7-9 hours
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Renal 70% unchanged, fecal 20% (including biliary metabolites), 10% metabolized
Category A/B
Category C
Antihistamine / Antiemetic
Antiemetic