Propoxy

Dextropropoxyphene

Clinical data
Trade names	Darvon
AHFS/Drugs.com	Monograph
MedlinePlus	a682325
License data	US FDA: Propoxyphene
Pregnancy category	AU: C
Routes of administration	oral, IV, rectal
ATC code	N02AC04 (WHO)
Legal status
Legal status	AU: S8 (Controlled) CA: Schedule I DE: Anlage II (Authorized trade only, not prescriptible) UK: Class C US: Schedule II and Schedule IV (when in dosage form)
Pharmacokinetic data
Bioavailability	40%
Protein binding	78%
Metabolism	Liver-mediated, CYP3A4-mediated N-demethylation (major), aromatic hydroxylation (minor) and ester hydrolysis (minor)
Biological half-life	6–12 hours; 30–36 hours (active metabolite, nordextropropoxyphene)
Excretion	Urine (major), breastmilk (minor)
Identifiers
IUPAC name (1S,2R)-1-benzyl-3-(dimethylamino)-2-methyl-1-phenylpropyl propionate
CAS Number	469-62-5 Y
PubChem CID	10100
IUPHAR/BPS	7593
DrugBank	DB00647 N
ChemSpider	9696 Y
UNII	S2F83W92TK
KEGG	D07809 Y
ChEBI	CHEBI:51173 Y
ChEMBL	CHEMBL1213351 Y
ECHA InfoCard	100.006.747
Chemical and physical data
Formula	C22H29NO2
Molar mass	339.471 g/mol
3D model (JSmol)	Interactive image
Melting point	75 °C (167 °F)
SMILES O=C(CC)O[C@@](CC1=CC=CC=C1)([C@@H](CN(C)C)C)C2=CC=CC=C2
InChI InChI=1S/C22H29NO2/c1-5-21(24)25-22(18(2)17-23(3)4,20-14-10-7-11-15-20)16-19-12-8-6-9-13-19/h6-15,18H,5,16-17H2,1-4H3/t18-,22+/m1/s1 Y Key:XLMALTXPSGQGBX-GCJKJVERSA-N Y
NY (what is this?)

Dextropropoxyphene is an analgesic in the opioid category, patented in 1955 and manufactured by Eli Lilly and Company. It is an optical isomer of levopropoxyphene. It is intended to treat mild pain and also has antitussive (cough suppressant) and local anaesthetic effects. The drug has been taken off the market in Europe and the US due to concerns of fatal overdoses and heart arrhythmias. Its onset of analgesia (pain relief) is said to be 20–30 minutes and peak effects are seen about 1.5–2 hours after oral administration.

Dextropropoxyphene is sometimes combined with acetaminophen. Trade names include Darvocet-N and Di-Gesic, Darvon with APAP (for dextropropoxyphene and paracetamol). The British approved name (i.e. the generic name of the active ingredient) of the paracetamol/dextropropoxyphene preparation is "co-proxamol" (sold under a variety of brand names); however, it has been withdrawn since 2007, and is no longer available to new patients, with exceptions. The paracetamol combination(s) are known as Capadex or Di-Gesic in Australia, Lentogesic in South Africa, and Di-Antalvic in France (unlike co-proxamol, which is an approved name, these are all brand names).

Dextropropoxyphene is known under several synonyms, including:

Dextropropoxyphene, like codeine, is a weak opioid, known to cause dependency among recreational users. Codeine is more commonly used; however, as codeine is, in essence, a prodrug that requires in vivo metabolism for efficacy, it is ineffective for some individuals with the "poor metabolizer" genotype of the liver enzyme CYP2D6. In people with this low-function isoform, dextropropoxyphene is particularly useful, as its metabolism does not require CYP2D6. It is also used for patients with digestive complaints, as it is less liable to worsen their symptoms.