Comparative Pharmacology
Head-to-head clinical analysis: LORATADINE versus PROMETHAZINE HYDROCHLORIDE CODEINE PHOSPHATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LORATADINE versus PROMETHAZINE HYDROCHLORIDE CODEINE PHOSPHATE.
LORATADINE vs PROMETHAZINE HYDROCHLORIDE; CODEINE PHOSPHATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Loratadine is a long-acting tricyclic antihistamine with selective peripheral H1-receptor antagonist activity. It inhibits histamine-induced vasodilation and bronchoconstriction.
Promethazine is a phenothiazine derivative that acts as a histamine H1 receptor antagonist, antiemetic, and sedative via blockade of central and peripheral H1 receptors and antagonism of dopamine D2 receptors. Codeine is an opioid agonist that binds to mu-opioid receptors in the CNS, producing analgesia and cough suppression; it also has antitussive effects via central action.
10 mg orally once daily
Promethazine hydrochloride 6.25-25 mg / codeine phosphate 10-20 mg (based on codeine component) orally every 4-6 hours as needed. Maximum codeine dose: 60 mg per dose, 120 mg per day.
None Documented
None Documented
Clinical Note
moderateLoratadine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Loratadine is combined with Fluticasone propionate."
Clinical Note
moderateLoratadine + Teriflunomide
"The metabolism of Teriflunomide can be decreased when combined with Loratadine."
Clinical Note
moderateLoratadine + Haloperidol
"The metabolism of Haloperidol can be decreased when combined with Loratadine."
Clinical Note
moderateLoratadine + Sulfisoxazole
Loratadine: 8-14 hours (mean ~10 hours). Active metabolite descarboethoxyloratadine: 17-24 hours (mean ~20 hours). Clinically, duration supports once-daily dosing.
Promethazine: 10-19 hours (terminal); Codeine: 2.4-4 hours (terminal), prolonged in hepatic impairment. Clinical context: Dosing interval typically 4-6 hours for codeine; promethazine accumulates with repeated dosing.
Approximately 40% excreted in urine as metabolites (primarily descarboethoxyloratadine) and 40% in feces as metabolites; <1% excreted unchanged.
Promethazine: Renal (70-80% as metabolites, <1% unchanged); Codeine: Renal (70-90% as metabolites, 5-15% unchanged). Biliary/feces: Minor (<10% total).
Category A/B
Category A/B
Antihistamine
Antihistamine / Antiemetic
"The metabolism of Sulfisoxazole can be decreased when combined with Loratadine."