Dihydromorphine is a semi-synthetic opioid structurally related to and derived from morphine. The 7,8-double bond in morphine is reduced to a single bond to get dihydromorphine. Dihydromorphine is a moderately strong analgesic and is used clinically in the treatment of pain and also is an active metabolite of the analgesic opioid drug dihydrocodeine. Dihydromorphine occurs in trace quantities in assays of opium on occasion, as does dihydrocodeine, dihydrothebaine, tetrahydrothebaine, etc. The process for manufacturing dihydromorphine from morphine for pharmaceutical use was developed in Germany in the late 19th century, with the synthesis being published in 1900 and the drug introduced clinically as Paramorfan shortly thereafter. A high-yield synthesis from tetrahydrothebaine was later developed.
Anileridine is a synthetic analgesic drug and is a member of the piperidine class of analgesic agents developed by Merck & Co. in the 1950s. It differs from pethidine (meperidine) in that the N-methyl group of meperidine is replaced by an N-aminophenethyl group, which increases its analgesic activity.
Levomethorphan (LVM) (INN, BAN) is an opioid analgesic of the morphinan family that has never been marketed. It is the L-stereoisomer of racemethorphan (methorphan). The effects of the two isomers of racemethorphan are quite different, with dextromethorphan (DXM) being an antitussive at low doses and a dissociative hallucinogen at much higher doses. Levomethorphan is about five times stronger than morphine.
Properidine is an opioid, an analgesic, and the isopropyl analog of pethidine. Properidine is under international control and is listed in the United States under the Controlled Substances Act (1970) as a Schedule I substance. It is a narcotic, with an Administrative Controlled Substances Code Number (ACSCN) of 9644 and a 2 gramme annual aggregate manufacturing quota as of 2014. The salt in use is hydrochloride, with a free base conversion ratio of 0.88.
Metopon is an opioid analogue that is a methylated derivative of hydromorphone which was invented in 1929 as an analgesic.
Phenadoxone is an opioid analgesic of the open chain class invented in Germany by Hoechst in 1947. It is one of a handful of useful synthetic analgesics which were used in the United States for various lengths of time in the 20 or so years after the end of the Second World War but which were withdrawn from the market for various or no known reason and which now are mostly in Schedule I of the United States' Controlled Substances Act of 1970, or in Schedule II but not produced or marketed in the US. Others on this list are ketobemidone (Ketogin), dextromoramide, phenazocine, dipipanone, piminodine (Alvodine), propiram (Algeril), anileridine (Leritine) and alphaprodine (Nisentil).
Hydroxypethidine (Bemidone) is an opioid analgesic that is an analogue of the more commonly used pethidine (meperidine). Hydroxypethidine is slightly more potent than meperidine as an analgesic, 1.5x meperidine in potency, and it also has NMDA antagonist properties like its close relative ketobemidone.
Normethadone, also known as desmethylmethadone or phenyldimazone, is a synthetic opioid analgesic and antitussive agent. Normethadone is listed under the Single Convention on Narcotic Drugs 1961 and is a Schedule I Narcotic controlled substance in the United States, with a DEA ACSCN of 9635 and an annual manufacturing quota of 2 grams. It has an effective span of action for about 14 days, and is 12 to 20 times stronger than morphine. The salts in use are the hydrobromide, hydrochloride (0.890), methyliodide (0.675), oxalate (0.766), picrate (0.563), and the 2,6-ditertbutylnapthalindisulphonate (0.480).
Metazocine is an opioid analgesic related to pentazocine. While metazocine has significant analgesic effects, mediated through a mixed agonist–antagonist action at the mu opioid receptor, its clinical use is limited by dysphoric and hallucinogenic effects which are most likely caused by activity at kappa opioid receptors and/or sigma receptors.
Allylprodine is an opioid analgesic that is an analog of prodine. It was discovered by Hoffman-La Roche in 1957 during research into the related drug pethidine. Derivatives were tested to prove the theory that phenolic and non-phenolic opioids bind at different sites of the opiate receptor.
Trimeperidine (Promedol) is an opioid analgesic that is an analogue of prodine. It was developed in the early 1950s in the USSR during research into the related drug pethidine.
Phenazocine is an opioid analgesic drug, which is related to pentazocine and has a similar profile of effects.
Phenampromide is an opioid analgesic from the ampromide family of drugs, related to other drugs such as propiram and diampromide. It was invented in the 1960s by American Cyanamid Co. Although never given a general release, it was trialled and 50 mg codeine ≈ 60 mg phenampromide. Tests on the 2 isomers showed that all of the analgesic effects were caused by the (S) isomer. Introduction of a phenyl group to the 4-position of the piperidine-ring produces a drug 60-fold more potent than morphine. The most potent reported derivative is 4-hydroxy-4-phenyl phenapromide which displays analgesic activity some x150 greater than morphine.
Benzethidine is a 4-phenylpiperidine derivative that is related to the clinically used opioid analgesic drug pethidine.
Furethidine is a 4-phenylpiperidine derivative that is related to the clinically used opioid analgesic drug pethidine (meperidine), but with around 25x higher potency. According to another source, Furethidine is 500/30 = 16.7 x the potency of pethidine.
Pethidine intermediate A is a 4-phenylpiperidine derivative that is a precursor to the opioid analgesic drug pethidine (meperidine). It is not known to have any analgesic activity in its own right, however other derivatives of pethidine with a 4-cyano group in place of the carboxylate ethyl ester have been found to be active, so pethidine intermediate A might also show opioid effects. It is scheduled by UN Single Convention on Narcotic Drugs. It is a Schedule II Narcotic controlled substance in the United States and has an ACSCN of 9232. The 2014 annual manufacturing quota was 6 grammes.
Normorphine is an opiate analogue, the N-demethylated derivative of morphine, that was first described in the 1950s when a large group of N-substituted morphine analogues were characterized for activity. The compound has relatively little opioid activity in its own right, but is a useful intermediate which can be used to produce both opioid antagonists such as nalorphine, and also potent opioid agonists such as N-phenethylnormorphine. with its formation from morphine catalyzed by the liver enzymes CYP3A4 and CYP2C8.
Methyldesorphine is an opioid analgesic. First synthesized in Germany in 1940 and patented in the US in 1952, it has a high potential for abuse as with any potent opioid agonist, and is sometimes found along with desomorphine as a component of the home-made opioid mixture known as "Krokodil" used in Russia and the neighboring former Soviet republics. It is approximately 15 times more potent than morphine as an analgesic but if the 6-7 bond is saturated, the β isomer is some 50 times more potent than morphine.
Racemoramide, or simply moramide, is an opioid analgesic and a racemic mixture of the substances dextromoramide and levomoramide, two enantiomers of a chiral molecule.
Noracymethadol (INN) is a synthetic opioid analgesic related to methadone that was never marketed. In a clinical trial of postpartum patients it was reported to produce analgesia comparable to that of morphine but with less nausea, dizziness, and drowsiness. Other side effects included salivation, ataxia, and respiratory depression that was reversible by naloxone. Similarly to many of its analogues, noracymethadol is a Schedule I controlled substance in the United States with an ACSCN of 9633 and 2013 annual manufacturing quota of 12 grammes. and is also controlled internationally under the United Nations Single Convention on Narcotic Drugs of 1961. The salts known are the gluconate and hydrochloride (0.903).
