Comparative Pharmacology
Head-to-head clinical analysis: HYDRAMINE versus PHENYLEPHRINE HYDROCHLORIDE AND PROMETHAZINE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRAMINE versus PHENYLEPHRINE HYDROCHLORIDE AND PROMETHAZINE HYDROCHLORIDE.
HYDRAMINE vs PHENYLEPHRINE HYDROCHLORIDE AND PROMETHAZINE HYDROCHLORIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antagonist of histamine H1 receptors, preventing histamine-mediated responses such as vasodilation, bronchoconstriction, and increased capillary permeability.
Phenylephrine is a selective alpha-1 adrenergic receptor agonist causing vasoconstriction; promethazine is a phenothiazine derivative that blocks histamine H1 receptors and has anticholinergic, antiemetic, and sedative effects.
50-100 mg IV/IM every 4-6 hours, maximum 400 mg per day. Also available as 50 mg oral tablets.
IV: 0.1-0.5 mg phenylephrine and 12.5-25 mg promethazine as a single dose.
None Documented
None Documented
Terminal elimination half-life 5.7 hours, range 4.2-7.7 hours; prolonged in hepatic impairment (up to 15 hours in cirrhosis)
Clinical Note
moderateDiphenhydramine + Deferasirox
"The serum concentration of Deferasirox can be increased when it is combined with Diphenhydramine."
Clinical Note
moderateDiphenhydramine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Fluticasone propionate."
Clinical Note
moderateDiphenhydramine + Tenofovir disoproxil
"The metabolism of Tenofovir disoproxil can be decreased when combined with Diphenhydramine."
Clinical Note
moderatePhenylephrine: 2-3 hours (terminal). Promethazine: 10-14 hours (terminal in adults; prolonged in elderly and hepatic impairment).
Primarily renal (95%) as metabolites; <5% unchanged; 5% fecal
Phenylephrine: renal (80% as unchanged drug and sulfate conjugates). Promethazine: renal (70-80% as metabolites and unchanged drug), fecal (20-30%).
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic
Diphenhydramine + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Diphenhydramine."