Comparative Pharmacology
Head-to-head clinical analysis: AZELASTINE HYDROCHLORIDE CHILDREN S ALLERGY versus PROMETHAZINE W CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AZELASTINE HYDROCHLORIDE CHILDREN S ALLERGY versus PROMETHAZINE W CODEINE.
AZELASTINE HYDROCHLORIDE CHILDREN'S ALLERGY vs PROMETHAZINE W/ CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Azelastine hydrochloride is a phthalazinone derivative that acts as a selective histamine H1-receptor antagonist. It inhibits the release of histamine and other mediators from mast cells, reduces chemotaxis, and decreases eosinophil activation. It also suppresses leukotriene and cytokine production.
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.
Azelastine hydrochloride nasal spray: 1 spray (137 mcg) per nostril twice daily; maximum 2 sprays per nostril twice daily.
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.
None Documented
None Documented
Terminal elimination half-life is 22–25 hours in adults; steady state achieved in 3–5 days. In children (6–11 years), half-life is similar (mean 22 hours).
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Primarily renal (approximately 75%), with about 50% as unchanged drug and 25% as metabolites via CYP3A4 and CYP2D6. Fecal excretion accounts for ~20%.
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic