Comparative Pharmacology
Head-to-head clinical analysis: HYDROXYZINE versus PROMETHAZINE VC PLAIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDROXYZINE versus PROMETHAZINE VC PLAIN.
HYDROXYZINE vs PROMETHAZINE VC PLAIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydroxyzine is a first-generation antihistamine that acts as a competitive antagonist at histamine H1 receptors in the gastrointestinal tract, blood vessels, and respiratory tract. It also exhibits sedative, anxiolytic, and antiemetic properties, possibly through central nervous system depression and anticholinergic effects.
Promethazine is a phenothiazine derivative with antihistaminic (H1 receptor antagonist), sedative, antiemetic, and anticholinergic effects. Phenylephrine is a sympathomimetic amine acting primarily on alpha-1 adrenergic receptors, causing vasoconstriction.
25-100 mg orally 3-4 times daily; 50-100 mg IM every 4-6 hours as needed. Maximum oral dose: 600 mg/day in divided doses.
Adults: 1 tablet (promethazine 6.25 mg, phenylephrine 10 mg) orally every 4-6 hours as needed, not to exceed 4 tablets in 24 hours.
None Documented
None Documented
Clinical Note
moderateHydroxyzine + Venlafaxine
"The risk or severity of adverse effects can be increased when Hydroxyzine is combined with Venlafaxine."
Clinical Note
moderateHydroxyzine + Nefazodone
"The risk or severity of adverse effects can be increased when Hydroxyzine is combined with Nefazodone."
Clinical Note
moderateHydroxyzine + Mifepristone
"Hydroxyzine may increase the QTc-prolonging activities of Mifepristone."
Clinical Note
moderateHydroxyzine + Fesoterodine
Terminal elimination half-life: 14-25 hours (mean ~20 h). In elderly or hepatic impairment, may be prolonged; antihistamine effect persists beyond half-life due to active metabolite.
Terminal elimination half-life is approximately 9–16 hours (mean ~12 hours) in adults; may be prolonged in hepatic impairment or elderly patients.
Renal: approximately 70% as metabolites, less than 1% unchanged. Fecal/biliary: minor. Cetirizine (active metabolite) also renally eliminated.
Primarily renal as inactive metabolites; approximately 70-80% excreted in urine, with about 20-30% in feces via biliary secretion. Less than 1% excreted unchanged.
Category A/B
Category A/B
Antihistamine
Antihistamine / Antiemetic
"The serum concentration of the active metabolites of Fesoterodine can be increased when Fesoterodine is used in combination with Hydroxyzine."