Dimethyltubocurarine (metocurine) is a non-depolarizing muscle relaxant. It binds to muscle acetylcholine receptor by bridging the to alpha and non-alpha subunits from the ligand binding site. Dimethyltubocurarine was used as an anesthesia adjunct to induce skeletal muscle relaxation and to reduce the intensity of muscle contractions in convulsive therapy.

Alcuronium (diallylnortoxiferine) is a semi-synthetic substance prepared from C-toxiferine I a bis-quaternary alkaloid obtained from Strychnos toxifera. Alcuronium is a neuromuscular blocking (NMB) agent, alternatively referred to as a skeletal muscle relaxant. Alcuronium is used for endotracheal intubation and to produce muscle relaxation in general anesthesia during surgical procedures. The pharmacological action of alcuronium is readily reversed by neostigmine, and it produced little histamine release. The major disadvantage of alcuronium is that it elicits a vagolytic effect produced by a selective atropine-like blockade of cardiac muscarinic receptors.

Thiocolchicoside is a muscle relaxant that has been authorised by national procedures in several EU Member States for use by mouth or injection into the muscles in the treatment of painful muscular disorders. Thiocolchicoside is marketed under the brand name Muscoril among others. Thiocolchicoside (TCC) is used clinically for its muscle relaxant, anti-inflammatory, and analgesic properties, and it has been shown to interact with gamma-aminobutyric acid (GABA) type A receptors (GABAARs) and strychnine-sensitive glycine receptors in the rat central nervous system.

Gallamine is a synthetic non-depolarizing neuromuscular blocking agent. It has been used to produce relaxation of skeletal muscle during surgery.

Febarbamate is a derivative of barbituric acid and carbamate, used for the treatment of generalized anxiety and alcohol withdrawal syndrome. The drug was marketed in Europe in the 1980s as a single agent or in combination with difebarbamate and phenobarbital, but it was later withdrawn from the market because of the potential risk of liver damage.

Pridinol mesilate is a centrally acting muscle relaxant that is used in the symptomatic treatment of muscle spasm. It is also used as the hydrochloride salt for its antimuscarinic activity in the management of parkinsonism.

Tolperisone is a centrally acting muscle relaxant first synthesized in 1956 and used in clinical practice since the 1960’s. Tolperisone is an aryl alkyl β-aminoketone with an asymmetric carbon atom α to the carbonyl group. The dextrorotatory enantiomer was reported less effective, however, no detailed analyses of the enantiomers are available. The precise mechanism of action of tolperisone is not fully known. The most prominent effect of tolperisone is its inhibitory action on pathways of spinal reflexes. It suppresses the mono and polysynaptic reflex transmission by both pre-synaptic and post-synaptic mechanisms.

Fazadinium (used as a bromide salt) is a muscle relaxant, which was applied in anesthesia under the name Fazadon. The current marketing status is unknown and the drug is supposed to be discontinued.

Eperisone is an antispasmodic drug approved in Japan for the treatment of of diseases characterized by muscle stiffness and pain. It is believed that eperisone exerts its effect through inhibition of sodium channels. The drug is still being marketed in Asia under the name Myonal (Square Pharmaceuticals).

Tetrazepam was the most widely prescribed muscle relaxant in Germany. After a series of studies, which have shown, that tetrazepam caused cutaneous adverse effects and toxic epidermal necrolysis, the drug was withdrawn from the market.