• Molecular NameHydroxyzine
  • SynonymHidroxizina [INN-Spanish]; Hydroksyzyny [Polish]; Hydroxine; Hydroxizine; Hydroxizinum; Hydroxycine; Hydroxyzin; Hydroxyzine Base; Hydroxyzine Hcl; Hydroxyzine Pamoate; Hydroxyzinum [INN-Latin]; Hydroxyzyne; Idrossizina [Dcit]
  • Weight374.912
  • Drugbank_IDDB00557
  • ACS_NO68-88-2
  • Show 2D model
  • LogP (experiment)3.5
  • LogP (predicted, AB/LogP v2.0)3.27
  • pka2.1, 7.1
  • LogD (pH=7, predicted)2.94
  • Solubility (experiment)N/A
  • LogS (predicted, ACD/Labs)(ph=7)-1.79
  • LogSw (predicted, AB/LogsW2.0)0.62
  • Sw (mg/ml) (predicted, ACD/Labs)4.07
  • No.of HBond Donors1
  • No.of HBond Acceptors4
  • No.of Rotatable Bonds8
  • TPSA35.94
  • StatusFDA approved
  • AdministrationOral, intramuscular injection
  • PharmacologyA first-generation antihistamine of the piperazine class that is an H1 receptor antagonist.
  • Absorption_valueN/A
  • Absorption (description)Rapidly absorbed from the gastrointestinal tract
  • Caco_2N/A
  • Bioavailability80.0
  • Protein binding93.0
  • Volume of distribution (VD)16 L/kg (adult) and 19 L/kg (children)
  • Blood/Plasma Partitioning ratio (D_blood)N/A
  • MetabollsmHydroxyzine is metabolized to an active metabolite, cetirizine. Plasma concentrations of cetirizine exceed those of parent drug
  • Half life20 h (adult) and 7.1 (children)
  • ExcretionUrine, Feces
  • Urinary ExcretionN/A
  • Clerance9.8 ml/min/kg (adult) and 32 ml/min/kg (children)
  • ToxicityA plasma concentration of 102.7 mg/L was reported 8.5 h after the ingestion of about 500 mg of hydroxyzine by a 13-month-old child; the child recovered within 72 h. [B. E. Magera,Pediatrics,1981, 67, 280–283.]
  • LD50 (rat)LD50=950 mg/kg
  • LD50 (mouse)N/A