Comparative Pharmacology
Head-to-head clinical analysis: FAYOSIM versus HYDROXYZINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FAYOSIM versus HYDROXYZINE.
FAYOSIM vs HYDROXYZINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
FAYOSIM (plecanatide) is a guanylate cyclase-C (GC-C) agonist. It binds to GC-C receptors on the luminal surface of intestinal epithelial cells, activating the receptor and increasing intracellular cyclic guanosine monophosphate (cGMP) levels. Elevated cGMP stimulates chloride and bicarbonate secretion into the intestinal lumen, enhancing fluid secretion and accelerating gastrointestinal transit, thereby promoting bowel movements.
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.
10 mg orally once daily
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.
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
12-16 hours in healthy adults; prolonged to 20-30 hours in moderate renal impairment (CrCl <50 mL/min) requiring dose adjustment.
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.
Primarily renal elimination, 80% unchanged drug in urine; 15% biliary/fecal; 5% metabolized.
Renal: approximately 70% as metabolites, less than 1% unchanged. Fecal/biliary: minor. Cetirizine (active metabolite) also renally eliminated.
Category C
Category A/B
Antihistamine
Antihistamine
"The serum concentration of the active metabolites of Fesoterodine can be increased when Fesoterodine is used in combination with Hydroxyzine."