Chlorphenamine

Chlorphenamine
Clinical data
Trade names	Chlor-Trimeton; Piriton; Chlor-Tripolon; Allergex
AHFS/Drugs.com	Monograph
MedlinePlus	a682543
Pregnancy; category	AU: A;
Routes of; administration	Oral, intravenous, intramuscular, subcutaneous
ATC code	R06AB04 (WHO) ;
Legal status
Legal status	AU: S3 (Pharmacist only); UK: P (Pharmacy medicines); US: OTC; CN: OTC;
Pharmacokinetic data
Bioavailability	25 to 50%
Protein binding	72%
Metabolism	Liver (CYP2D6)
Elimination half-life	13.9–43.4 hours
Excretion	Kidney
Identifiers
	IUPAC name 3-(4-Chlorophenyl)-N,N-dimethyl-3-(pyridin-2-yl)-propan-1-amine;
CAS Number	132-22-9 ;
PubChem CID	2725;
IUPHAR/BPS	1210;
DrugBank	DB01114 ;
ChemSpider	2624 ;
UNII	3U6IO1965U;
KEGG	D07398 ;
ChEBI	CHEBI:52010 ;
ChEMBL	ChEMBL505 ;
CompTox Dashboard (EPA)	DTXSID0022804 ;
ECHA InfoCard	100.004.596
Chemical and physical data
Formula	C16H19ClN2
Molar mass	274.79 g·mol−1
3D model (JSmol)	Interactive image;
Solubility in water	0.55 g/100 mL, liquid mg/mL (20 °C)
	SMILES Clc1ccc(cc1)C(c2ncccc2)CCN(C)C;
	InChI InChI=1S/C16H19ClN2/c1-19(2)12-10-15(16-5-3-4-11-18-16)13-6-8-14(17)9-7-13/h3-9,11,15H,10,12H2,1-2H3 ; Key:SOYKEARSMXGVTM-UHFFFAOYSA-N ;
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Chlorphenamine (CP, CPM), also known as chlorpheniramine, is an antihistamine used to treat the symptoms of allergic conditions such as allergic rhinitis (hay fever). It is taken orally (by mouth). The medication takes effect within two hours and lasts for about 4–6 hours. It is a first-generation antihistamine and works by blocking the histamine H₁ receptor.

Common side effects include sleepiness, restlessness, and weakness. Other side effects may include dry mouth and wheeziness.

Chlorpheniramine was patented in 1948 and came into medical use in 1949. It is available as a generic medication and over the counter.

In 2022, it was the 291st most commonly prescribed medication in the United States, with more than 400,000 prescriptions.