Racemic phenibut (beta-phenyl-gamma-aminobutyric acid or 4-amino-3-phenylbutyric acid) is a neuropsychotropic drug that was discovered and introduced into clinical practice in Russia in the 1960s. In pharmacological tests of locomotor activity, antidepressant and pain effects, S-phenibut was inactive. In contrast, R-phenibut turned out to be two times more potent than racemic phenibut in most of the tests. Racemic phenibut and R-phenibut demonstrated an affinity for GABAB receptors, in contrast, S-phenibut was not able to bind receptors. Pharmacological activity of racemic phenibut relies on R-phenibut and this correlates to the binding affinity of enantiomers of phenibut to the GABAB receptor. Both S- and R-phenibut bind to the α2-δ subunit of voltage-dependent calcium channels and exert gabapentin-like anti-nociceptive effects. In addition S-isomer was found to be a substrate of gamma-aminobutyric acid aminotransferase, however, the R-isomer is a competitive inhibitor.

Napelline is a diterpenoid alkaloid, from plants of the Aconitum genus, Ranunculaceae. It is a potent antiarrhythmic of class I with weak hypotensive and N-cholinoblocking effects. Napelline has analgesic and anti-inflammatory activity. Napelline has a stronger antiarrhythmic activity than Quinidine or Procaïnamide. 10(-4) - 10(-5) M block inward Na+ currents

Pamoic acid, also called embonic acid, is a naphthoic acid derivative, used as a counter ion of a drug compound to increase the solubility of the drug in water. Pamoic acid has agonist activity for the orphan G protein-coupled receptor GPR35 by which it activates ERK and beta-arrestin2, and causes antinociceptive activity. Although (like other drug salts) it has been considered an inactive compound by the FDA.

Gelsemine is the principal alkaloid in Gelsemium sempervirens Ait. A single intrathecal injection of gelsemine produced potent and specific antinociception in formalin-induced tonic pain, bone cancer-induced mechanical allodynia, and spinal nerve ligation-induced painful neuropathy. Gelsemine exhibits potent and specific antinociception in chronic pain by acting at spinal α3 glycine receptors. Gelsemine is an effective agent for treatment of both neuropathic pain and sleep disturbance in PSNL mice; anterior cingulate cortex might play a role in the hypnotic effects of gelsemine.

JTC 801 was developed by Japan Tobacco as a novel opioid receptor-like1 (ORL(1)) receptor antagonist. It was found, that JTC-801 completely antagonized the suppression of nociceptin on the forskolin-induced accumulation of cyclic AMP using ORL(1) receptor expressing HeLa cells in vitro. JTC 801 produced analgesic effects and was studied in phase II of a clinical trial for the treatment of neuropathic, cancer and postoperative pain. Nevertheless, that studies were discontinued.

Chelerythrine is a kind of benzo[c] phenanthridine alkaloids, which is widely found in plant of Fumariaceae, Papaveraceae, Ranunculaceae and Rutaceae families. Chelerythrine is a potent and specific inhibitor of protein kinase C. In addition chelerythrine inhibits pro-survival protein Bcl(XL) thereby inducing apoptosis. It exerts antitumor properties.

DBO-83 is a 3,8-diazabicyclo[3.2.1]octane derivative with antinociceptive properties. DBO-83 exhibits high affinity for the α4β2 subtype and is a full agonist at α4β2 and ganglionic receptors but lacks appreciable activity at neuromuscular receptors. DBO-83 exhibits antinociceptive activity in both rat and mouse models of acute and persistent pain. In addition DBO-83 modulates memory functions in rodents.

Beta-erythroidine is an organic heterotetracyclic indole alkaloid isolated from the seeds and other parts of Erythrina species. A drug used to produce muscle relaxation (excepting neuromuscular blocking agents). Its primary clinical and therapeutic use is the treatment of muscle spasm and immobility associated with strains, sprains, and injuries of the back and, to a lesser degree, injuries to the neck. Also used for the treatment of a variety of clinical conditions that have in common only the presence of skeletal muscle hyperactivity, for example, the muscle spasms that can occur in multiple sclerosis. Beta-erythroidine is a neuronal nicotinic acetylcholine receptor antagonist. The beta-erythroidine and its more potent derivative (2,7-dihydro) have been used as muscular relaxants in numerous clinical applications. This activity is attributed to a antagonistic action of the dihydro-beta-erythroidine with the nicotinic receptors of acetyl choline.

Beta-erythroidine is an organic heterotetracyclic indole alkaloid isolated from the seeds and other parts of Erythrina species. A drug used to produce muscle relaxation (excepting neuromuscular blocking agents). Its primary clinical and therapeutic use is the treatment of muscle spasm and immobility associated with strains, sprains, and injuries of the back and, to a lesser degree, injuries to the neck. Also used for the treatment of a variety of clinical conditions that have in common only the presence of skeletal muscle hyperactivity, for example, the muscle spasms that can occur in multiple sclerosis. Beta-erythroidine is a neuronal nicotinic acetylcholine receptor antagonist. The beta-erythroidine and its more potent derivative (2,7-dihydro) have been used as muscular relaxants in numerous clinical applications. This activity is attributed to a antagonistic action of the dihydro-beta-erythroidine with the nicotinic receptors of acetyl choline.

Beta-erythroidine is an organic heterotetracyclic indole alkaloid isolated from the seeds and other parts of Erythrina species. A drug used to produce muscle relaxation (excepting neuromuscular blocking agents). Its primary clinical and therapeutic use is the treatment of muscle spasm and immobility associated with strains, sprains, and injuries of the back and, to a lesser degree, injuries to the neck. Also used for the treatment of a variety of clinical conditions that have in common only the presence of skeletal muscle hyperactivity, for example, the muscle spasms that can occur in multiple sclerosis. Beta-erythroidine is a neuronal nicotinic acetylcholine receptor antagonist. The beta-erythroidine and its more potent derivative (2,7-dihydro) have been used as muscular relaxants in numerous clinical applications. This activity is attributed to a antagonistic action of the dihydro-beta-erythroidine with the nicotinic receptors of acetyl choline.