A centrally acting skeletal muscle relaxant whose mechanism of action is not completely understood but may be related to its sedative actions. Carisoprodol is indicated for the relief of discomfort associated with acute, painful musculoskeletal conditions in adults. Most common adverse reactions (incidence > 2%) are drowsiness, dizziness, and headache. Carisoprodol might be mixtured with Aspirin and Codeine Phosphate. Studies indicating increased risk of abuse or addiction led to withdrawal of the drug from the market in Norway and other EU countries in 2008.

Methocarbamol is a central muscle relaxant for skeletal muscles, used to treat spasms. It is structurally related to guaifenesin. Methocarbamol's exact mechanism of causing skeletal muscle relaxation is unknown. It is thought to work centrally, perhaps by general depressant effects. It has no direct relaxant effects on striated muscle, nerve fibers, or the motor endplate. It will not directly relax contracted skeletal muscles. The drug has a secondary sedative effect. Methocarbamol is used for use as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions. Under the trade name Robaxin, Methocarbamol is marketed by Actient Pharmaceuticals in the United States and Pfizer in Canada.

Styramate is a nonsedative skeletal muscle relaxant drug, developed by the Armour Pharmaceutical Company in 1952. The drug induces relaxation of skeletal musculus by interruption of nerve transmission in the spinal cord and brain stem rather than by exerting a blocking effect at the junction between the motor nerves and the muscles. In mouse studies styramate was found to exert a selective antagonism to hindleg extensor tonic spasm, induced by maximal electroshock, pentylenetetrazol, and strychnine sulfate. In the clinic, the drug was used in patients with neurologic and neuromuscular disorders, secondary muscular spasms. Styramate is marketed in South Africa under tradename Sinaxamol.

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in Europe in the 1980s as a single agent or in combination with difebarbamate and phenobarbital, but it was later withdrawn from the market because of the potential risk of liver damage.

Phenprobamate (3-phenylpropylcarbamate, Gamaquil, Isotonil) is a centrally acting muscle relaxant with mild sedative and anticonvulsant effects. Muscle relaxants can enhance and prolong the effect of narcotic drugs and enable to obtain same effect with a smaller amount of alcohol or illicit substance. Almost all of the centrally acting muscle relaxants have varying sedative effects on which their abuse potential mainly depends. Overdose is similar to barbiturates. Its mechanism of action is probably similar to meprobamate. Phenprobamate was previously used in humans as an anxiolytic, and is still sometimes used in general anesthesia and for treating muscle cramps and spasticity. Phenprobamate is still used in some European countries, but it has generally been replaced by newer drugs. Phenprobamate is metabolized by oxidative degradation of the carbamate group and ortho-hydroxylation of the benzene ring, and is eliminated in urine by the kidneys. Doses range from 400 to 800 mg, up to 3 times a day.