Comparative Pharmacology
Head-to-head clinical analysis: HYDROXYZINE versus ISOCLOR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDROXYZINE versus ISOCLOR.
HYDROXYZINE vs ISOCLOR
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.
Chlorpheniramine is an antihistamine (H1-receptor antagonist) that blocks the action of histamine, reducing allergy symptoms. Pseudoephedrine is a sympathomimetic amine that acts as a decongestant by stimulating alpha-adrenergic receptors, causing vasoconstriction in the nasal mucosa.
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.
Oral: 1 tablet (chlorpheniramine 4 mg / pseudoephedrine 60 mg) every 4-6 hours, not to exceed 4 tablets per 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.
Approximately 2-4 hours in patients with normal renal function; prolonged to 8-12 hours in renal impairment (CrCl <30 mL/min).
Renal: approximately 70% as metabolites, less than 1% unchanged. Fecal/biliary: minor. Cetirizine (active metabolite) also renally eliminated.
Primarily renal; approximately 60-70% of a dose excreted unchanged in urine within 24 hours. Biliary/fecal excretion accounts for <10%.
Category A/B
Category C
Antihistamine
Antihistamine/Decongestant Combination
"The serum concentration of the active metabolites of Fesoterodine can be increased when Fesoterodine is used in combination with Hydroxyzine."