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Systematic (IUPAC) name
CAS number 357-56-2
ATC code N02AC01
PubChem 92943
Chemical data
Formula C25H32N2O2 
Mol. mass 392.534
Pharmacokinetic data
Bioavailability  ?
Metabolism  ?
Half life  ?
Excretion  ?
Therapeutic considerations
Pregnancy cat.


Legal status

Schedule I(US)

Routes  ?

Dextromoramide (Palfium®, Palphium®, Jetrium®, Dimorlin®) is the right-handed isomer of the moramide molecule. The left handed molecule is called levomoramide, and a mixture of the two is called racemoramide. Its full chemical name is (+)-1-(3-Methyl-4-morpholino-2,2-diphenylbutyryl)pyrrolidine, and its molecular formula: C25H32N2O2, with an atomic weight of ~392.5. It is one of a group of molecules known as substituted α,α-Diphenyl-γ-Amino-Butyramides.

It is a powerful opioid analgesic, and as such is subject to drug prohibition regimes, both internationally through UN treaties, and by the criminal law of individual states.

It was discovered and patented in 1956 by Dr Paul Janssen at Janssen Pharmaceutica, who also discovered fentanyl, another important synthetic opioid, widely used to treat pain and in combination with other drugs as an anaesthetic. It has the proprietary name Palfium, though as of mid 2004 the drug was discontinued in the UK due to limited supplies of precursor chemicals.

As is the case with so many drug discoveries, dextromoramide was discovered by accident during research into almost identical compounds, namely α,α-Diphenyl-γ-Dialkyamino-Butyramides, which show no analgesic activity, but are extremely active physiologically as inhibitors of gastric secretions in man.

In many countries dextromoramide is unused, for example the USA, where it is considered a Schedule 1 drug, alongside cannabis and LSD, as having no medicinal uses. It is still rarely used in Australia, but prescription is avoided due to its abuse potential and so use of Palfium is now mainly limited to terminal care.

The typical dose is 5mg four hourly for cancer pain - the drug has a short half life comparable with pethidine. Dextromoramide is also used as a short-acting analgesic for minor surgical procedures. In this case it is administered sublingually and reaches a therapeutic concentration after around 12 minutes.

Dextromoramide was much favoured by drug abusers in Australia in the 1970s. A single case report and a review of the subject appears in the Australian Journal of Pharmacy 1980;61:641-644


  • Den Otter G, Pain control with dextromoramide (pyrrolamidolum, R 875, palfium), Ned Tijdschr Geneeskd. 1958 Aug 23;102(34):1637-41.
  • Lasagna L, De Kornfeld T, Safar P, A clinical trial of dextromoramide, (R 875, SKF D-5137), J Chronic Dis. 1958 Dec;8(6):689-93.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dextromoramide". A list of authors is available in Wikipedia.
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