Propiomazine

Propiomazine

Clinical data
Routes of administration	Intramuscular, intravenous
ATC code	N05CM06 (WHO)
Pharmacokinetic data
Protein binding	81%
Identifiers
IUPAC name 1-[10-(2-dimethylaminopropyl)-10H-phenothiazin-2-yl]propan-1-one
CAS Number	362-29-8
PubChem CID	4940
DrugBank	APRD00339
ChemSpider	4771 Y
UNII	242Z0PM79Y
ChEMBL	ChEMBL1201210
CompTox Dashboard (EPA)	DTXSID1023520
ECHA InfoCard	100.006.043
Chemical and physical data
Formula	C20H24N2OS
Molar mass	340.483 g/mol g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C(c2cc1N(c3c(Sc1cc2)cccc3)CC(N(C)C)C)CC
InChI InChI=1S/C20H24N2OS/c1-5-18(23)15-10-11-20-17(12-15)22(13-14(2)21(3)4)16-8-6-7-9-19(16)24-20/h6-12,14H,5,13H2,1-4H3 Y Key:UVOIBTBFPOZKGP-UHFFFAOYSA-N Y
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Propiomazine (Largon, Propavan, Indorm, Serentin, Indorm, Dorevane, Dorevan) is an antihistamine blocking H1 receptors. It is used to treat insomnia, and to produce sleepiness or drowsiness and to relieve anxiety before or during surgery or other procedures and in combination with analgetics also during labor. Propiomazine is a phenothiazine, but is not used as a neuroleptic because it does not block dopamine receptors well.

Mechanism of action

Propiomazine is an antagonist at types 1, 2, and 4 dopamine receptors, serotonin (5-HT) receptor types 2A and 2C, muscarinic receptors 1 through 5, alpha(1)-receptors, and histamine H1-receptors. Propiomazine's antipsychotic effect is due to antagonism at dopamine and serotonin type 2 receptors, with greater activity at serotonin 5-HT2 receptors than at dopamine type-2 receptors. This may explain the lack of extrapyramidal effects. Propiomazine does not appear to block dopamine within the tubero-infundibular tract, explaining the lower incidence of hyperprolactinemia than with typical antipsychotic agents or risperidone.

Side effects

Rare, serious side effects include convulsions (seizures); difficult or unusually fast breathing; fast or irregular heartbeat or pulse; fever (high); high or low blood pressure; loss of bladder control; muscle stiffness (severe); unusual increase in sweating; unusually pale skin; and unusual tiredness or weakness.

Drowsiness is a usual side effect, and propiomazine was blamed on Kerry Katona's October 2008 interview on This Morning where she was accused of being under the influence of drink or drugs, as she appeared slurred and drowsy.