What is "propiram"

n. (context pharmaceutical drug English) A particular narcotic painkiller.

Propiram (Algeril, Dirame, Bay 4503) is a partial mu opioid receptor agonist and weak mu antagonist analgesic from the ampromide family of drugs. It was invented in 1963 in the United Kingdom by Bayer but was not widely marketed, although it saw some limited clinical use, especially in dentistry. A report in the reference Drug Facts & Comparisons, 56th (2002) Edition reports that research about the drug has increased in the past few years, having reached the (albeit restricted) Stage III clinical trial process in the United States and Canada. Propiram is currently a Schedule I/Narcotic controlled substance in the United States with an ACSCN of 9649 and a zero annual aggregate manufacturing quota as of 2014. It has been almost exclusively used as the fumarate salt, which has a free base conversion ratio of 0.70.

Propiram exhibits weak opioid antagonist activity on the mu receptor—quite a bit weaker than its agonist effects—and the effect on kappa and delta opioid, sigma receptors, or the NMDA system are not well understood. Other drugs of the partial mu-opioid agonist/antagonist type include meptazinol, buprenorphine, butorphanol, phenazocine, nalbuphine, pentazocine, dezocine and its relatives.

With about 10 per cent of the analgesic potency of morphine with 50 mg being equivalent to more than 60 mg of codeine or 50 mg of pentazocine in many patients, propiram is an effective analgesic comparable to other drugs such as these as well as pethidine, with a normal dose of around 50–100 mg and a duration of action of 3 to 6 hours. It is more potent and effective than codeine, and longer lasting and with a faster onset of action compared to pethidine. Side effects include sedation, dizziness, nausea and vomiting. Propiram has been available in oral, rectal, and injectable formulations, with bioavailability above 97 per cent after oral administration. Many related compounds are known, although only propiram was ever commercialised.