Comparative Pharmacology
Head-to-head clinical analysis: CLARITIN D versus PROMETHAZINE DM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CLARITIN D versus PROMETHAZINE DM.
CLARITIN-D vs PROMETHAZINE DM
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 antagonism. Pseudoephedrine is a sympathomimetic amine that acts as a decongestant by stimulating alpha-adrenergic receptors in the respiratory tract mucosa, causing vasoconstriction.
Promethazine is a phenothiazine derivative that acts as a histamine H1 receptor antagonist, antiemetic via blockade of dopamine D2 receptors in the chemoreceptor trigger zone, and sedative via central anticholinergic effects. Dextromethorphan is an NMDA receptor antagonist and sigma-1 receptor agonist, suppressing cough by central action on the cough center.
One tablet (5 mg loratadine/120 mg pseudoephedrine sulfate) orally every 12 hours; do not exceed 2 tablets in 24 hours.
2 teaspoonfuls (10 mL) orally every 4-6 hours, not to exceed 8 teaspoonfuls (40 mL) per 24 hours.
None Documented
None Documented
Loratadine: 8-14 h (mean 11 h); desloratadine: 17-24 h (mean 21 h). Pseudoephedrine: 4-8 h (mean 6 h), prolonged in alkaline urine.
16-19 hours (terminal); note: effect may last longer due to active metabolites and tissue binding
Loratadine: 40% renal (metabolites), ~40% fecal; desloratadine: 33% renal, 66% fecal. Pseudoephedrine: 70-90% renal unchanged, 1-2% biliary.
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal (20-30%)
Category C
Category A/B
Antihistamine/Decongestant Combination
Antihistamine / Antiemetic