Etonitazene is a potent and selective mu-opioid agonist. It was developed in CIBA. Administration of etonitazene may induce respiratory depression, and therefor etonitazene is not used in humans. Etonitazene is explicitly listed as an illegal drug under UN convention and is illegal throughout the world.

ORG-28611 (SCH-900,111) is a potent cannabinoid receptor full agonist, developed by Organon International for treatment pain. In preclinical studies, Org 28611 exhibited high affinity for both CB1 and CB2 cannabinoid receptors, as determined by radioligand competition binding assays and rapidly metabolized by mouse and human hepatic microsomes and showed higher total levels in the brain compared to plasma. In clinical trials, Org 28611 does not provide enough sedation for outpatient surgical procedures, does not induce anterograde amnesia and causes undesirable subjective effects at higher doses. However, bolus doses up to 3 μ/kg (with maximum initial plasma concentrations of 24 ng/mL) or mean plasma levels up to 4 ng/mL are well tolerated and make it worthwhile to further explore the analgesic or antiemetic properties.

Levomethorphan ( L-stereoisomer of racemethorphan) is an opioid analgesic of the morphinan family that has never been marketed. Levomethorphan is a methylated prodrug of levorphanol, that undergoes hepatic demethylation, converting it to the active form. Levomethorphan (via it’s active form levorphanol)functions as a potent agonist of all three of the opioid receptors, μ, κ (κ1 and κ3 but notably not κ2), and δ, as an NMDA receptor antagonist, and as a serotonin-norepinephrine reuptake inhibitor. Via activation of the KOR, levomethorphan can produce dysphoria and psychotomimetic effects such as dissociation and hallucinations. Levomethorphan is listed under the Single Convention on Narcotic Drugs 1961 and is regulated like morphine in most countries. In the United States it is a Schedule II Narcotic controlled substance.

Famprofazone, a nonsteroidal anti-inflammatory agent, is found in a multi-ingredient medication (Gewodin) used for pain relief. It is available over-the-counter in Taiwan. Famprofazone transforms to methamphetamine (MA) and amphetamine (AM) following administration, which is responsible for the side effects of the drug. For example, famprofazone user might be interpreted as an illicit MA abuser in Taiwan because the user's urine tested positive for MA.

Normorphine is an opiate analog, specifically the N-demethylated derivative of morphine. It was first described in the 1953 as part of an effort to characterize N-substituted morphine analogs. Normorphine has relatively little opioid activity, but it is a useful intermediate for the production of more potent morphine analogs. It is also a major metabolite of morphine.

T-62 ((2-amino-4,5,6,7-tetrahydro-1-benzothien-3-yl)(4-chlorophenyl)methanone) is a small-molecule allosteric potentiator of agonist function at the adenosine A1 receptor, developed by Edward Leung for the treatment of various pain states in a mammal and human subjects.

Tetrodotoxin (TTX) is a potent marine neurotoxin that blocks voltage-gated sodium channels (VGSCs). VGSCs play a critical role in neuronal function under both physiological and pathological conditions. TTX has been extensively used to functionally characterize VGSCs, which can be classified as TTX-sensitive or TTX-resistant channels according to their sensitivity to this toxin. Wex Pharmaceuticals is investigating tetrodotoxin for the treatment of chronic and breakthrough pain. The toxin is currently undergoing Phase III clinical trials in Canada as a systemic analgesic for inadequately controlled pain due to advanced cancer, especially where the pain has neuropathic features. In addition, TTX is in Phase II clinical trials to study its ability in moderate to severe neuropathic pain caused by chemotherapy.

Licofelone (ML 3000) is a pyrrolizine derivative originally discovered by Merckle GmbH and developed by EuroAllaince with a unique pharmacological profile, which comprises optimal gastrointestinal tolerability and high analgesic and anti-inflammatory activity. These effects are due to balanced and selective inhibition of both cyclo-oxygenase and 5-lipoxygenase. Inhibition of 5-lipoxygenase may reduce the gastrointestinal toxicity associated with other non steroidal anti-inflammatory drugs, which only inhibit cyclooxygenase. Licofelone also has antipyretic and antiaggregatory properties. Clinical and preclinical trials were also undertaken for osteoarthritis, rheumatoid arthritis, asthma, pain and inflammation. However, development for these indications appear to have been discontinued.

Pincainide is a new beta-amino anilide with local anesthetic properties. It has been shown to be 3 times more potent than lidocaine as a local anaesthetic on desheathed frog sciatic nerve. It was found to be effective against arrhythmias induced in guinea-pigs by ouabain infusion or by administration of adrenaline and chloroform. Pincainide not only inhibited the influx of Ca 2+ and increased 45Ca efflux, thus reducing the contractile responses induced in rat aorta by noradrenaline and high K +, but it also inhibited other effects related to the noradrenaline-induced release of intracellular Ca 2+ stores. Further studies, however, must be performed in experimental models of arrhythmias before the effectiveness of pincainide as an antiarrhythmic drug can be established.

Dexivacaine is a local anesthetic drug that has minimal and non-significant side effects.