4614 Promethazine A phenothiazine derivative with histamine H1-blocking, antimuscarinic, and sedative properties. It is used as an antiallergic, in pruritus, for motion sickness and sedation, and also in animals. [PubChem] 60-87-7 4927 C17H20N2S White powder. 60 °C 190-192 °C at 3.00E+00 mm Hg 15.6 mg/L (at 24 °C) On average, 88% of a promethazine dose is absorbed after oral administration; however, the absolute bioavailability is only 25% because of first-pass clearance. Like other H1-antagonists, promethazine competes with free histamine for binding at H1-receptor sites in the GI tract, uterus, large blood vessels, and bronchial muscle. The relief of nausea appears to be related to central anticholinergic actions and may implicate activity on the medullary chemoreceptor trigger zone. Hepatic Route of Elimination: Promethazine hydrochloride is metabolized in the liver, with the sulfoxides of promethazine and N-desmethylpromethazine being the predominant metabolites appearing in the urine. Half Life: 16-19 hours IV, Mouse: LD₅₀=55mg/kg No indication of carcinogenicity to humans (not listed by IARC). For the treatment of allergic disorders, and nausea/vomiting. Symptoms of overdose include mild depression of the central nervous system and cardiovascular system to profound hypotension, respiratory depression, unconsciousness, and sudden death. Other reported reactions include hyperreflexia, hypertonia, ataxia, athetosis, and extensor-plantar reflexes (Babinski reflex). 2014-08-30T21:04:24Z 2026-03-31T19:07:59Z Promethazine C07404 8461 DB01069 true CC(CN1C2=CC=CC=C2SC2=CC=CC=C12)N(C)C C17H20N2S InChI=1S/C17H20N2S/c1-13(18(2)3)12-19-14-8-4-6-10-16(14)20-17-11-7-5-9-15(17)19/h4-11,13H,12H2,1-3H3 PWWVAXIEGOYWEE-UHFFFAOYSA-N 284.419 284.13471934 Exogenous Solid 4.81 CHEMBL643 4758 <p><a href="http://www.drugsyn.org/Promethazine.htm">DrugSyn.org</a></p> CHEM003520 DTXSID7023518 NS00010423 dimethyl[1-(10H-phenothiazin-10-yl)propan-2-yl]amine