Butorphanol is a morphinan-type synthetic agonist–antagonist opioid analgesic developed by Bristol-Myers. Butorphanol is most closely structurally related to levorphanol. Butorphanol is available as the tartrate salt in injectable, tablet, and intranasal spray formulations. The tablet form is only used in dogs, cats and horses due to low bioavailability in humans.
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.
Methorphan comes in two isomeric forms, each with differing pharmacology and effects:
Thebacon, or dihydrocodeinone enol acetate, is a semisynthetic opioid that is similar to hydrocodone and is most commonly synthesised from thebaine. Thebacon was invented in Germany in 1924, four years after the first synthesis of hydrocodone. Thebacon is a derivative of acetyldihydrocodeine, where only the 6–7 double bond is saturated. Thebacon is marketed as its hydrochloride salt under the trade name Acedicon, and as its bitartrate under Diacodin and other trade names. The hydrochloride salt has a free base conversion ratio of 0.846. Other salts used in research and other settings include thebacon's phosphate, hydrobromide, citrate, hydroiodide, and sulfate.
Metopon is an opioid analogue that is a methylated derivative of hydromorphone which was invented in 1929 as an analgesic.
Benzylmorphine (Peronine) is a semi-synthetic opioid narcotic introduced to the international market in 1896 and that of the United States very shortly thereafter. It is much like codeine, containing a benzyl group attached to the morphine molecule just as the methyl group creates codeine and the ethyl group creates ethylmorphine or dionine. It is about 90% as strong as codeine by weight.
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.
Dimethylthiambutene (N,N-Dimethyl-1-methyl-3,3-di-2-thienylallylamine, DMTB, trade names Ohton, Aminobutene, Dimethibutin, Kobaton, Takaton, Dimethibutin) is an opioid analgesic drug, most often used in veterinary medicine in Japan and to a lesser extent in other countries in the region and around the world. It is the most prominent and widely used of the thiambutenes, a series of open-chain opioids structurally related to methadone which are also called the thienyl derivative opioids which also includes diethylthiambutene and ethylmethylthiambutene, as well as the non-opioid cough suppressant tipepidine.
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.
Meprodine is an opioid analgesic that is an analogue of pethidine (meperidine). It is closely related to the drug prodine, the only difference being that meprodine has an ethyl group rather than a methyl at the 3-position of the piperidine ring.
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 research found that 60 mg of phenampromide is equivalent to about 50 mg of codeine. Tests on its two enantiomers 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.
Proheptazine is an opioid analgesic related to pethidine. It was invented in the 1960s.
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 four-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.
Alphamethadol (INN), or α-methadol, also known as alfametadol, is a synthetic opioid analgesic. It is an isomer of dimepheptanol (methadol), the other being betamethadol (β-methadol). Alphamethadol is composed of two isomers itself, L-α-methadol, and D-α-methadol. Both of alphamethadol's isomers bind to and activate the μ-opioid receptor and are active as opioid analgesics, similarly to those of alphacetylmethadol (α-acetylmethadol).
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.
Racemorphan, or morphanol, is the racemic mixture of the two stereoisomers of 17-methylmorphinan-3-ol, each with differing pharmacology and effects:
Isomethadone (INN, BAN; trade name Liden; also known as isoamidone) is a synthetic opioid analgesic and antitussive related to methadone that was used formerly as a pharmaceutical drug but is now no longer marketed. Isomethadone was used as both an analgesic and antitussive. It binds to and activates both the μ- and δ-opioid receptors, with the (S)-isomer being the more potent of the two enantiomers. Isomethadone is a Schedule II controlled substance in the United States, with an ACSCN of 9226 and a 2014 aggregate manufacturing quota of 5 g. The salts in use are the hydrobromide (HBr, free base conversion ratio 0.793), hydrochloride (HCl, 0.894), and HCl monohydrate (0.850). Isomethadone is also regulated internationally as a Schedule I controlled substance under the United Nations Single Convention on Narcotic Drugs of 1961.
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