A muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeutic groups: neuromuscular blockers and spasmolytics. Neuromuscular blockers act by interfering with transmission at the neuromuscular end plate and have no central nervous system (CNS) activity. They are often used during surgical procedures and in intensive care and emergency medicine to cause temporary paralysis. Spasmolytics, also known as "centrally acting" muscle relaxant, are used to alleviate musculoskeletal pain and spasms and to reduce spasticity in a variety of neurological conditions. While both neuromuscular blockers and spasmolytics are often grouped together as muscle relaxant, the term is commonly used to refer to spasmolytics only.
Methocarbamol, sold under the brand name Robaxin among others, is a medication used for short-term musculoskeletal pain. It may be used together with rest, physical therapy, and pain medication. It is less preferred in low back pain. It has limited use for rheumatoid arthritis and cerebral palsy. Effects generally begin within half an hour. It is taken by mouth or injection into a vein.
Quazepam, sold under brand name Doral among others, is a relatively long-acting benzodiazepine derivative drug developed by the Schering Corporation in the 1970s. Quazepam is used for the treatment of insomnia including sleep induction and sleep maintenance. Quazepam induces impairment of motor function and has relatively selective hypnotic and anticonvulsant properties with considerably less overdose potential than other benzodiazepines. Quazepam is an effective hypnotic which induces and maintains sleep without disruption of the sleep architecture.
Medazepam is a drug that is a benzodiazepine derivative. It possesses anxiolytic, anticonvulsant, sedative, and skeletal muscle relaxant properties. It is known by the following brand names: Azepamid, Nobrium, Tranquirax, Rudotel, Raporan, Ansilan and Mezapam. Medazepam is a long-acting benzodiazepine drug. The half-life of medazepam is 36–200 hours.
Prazepam is a benzodiazepine derivative drug developed by Warner-Lambert in the 1960s. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. Prazepam is a prodrug for desmethyldiazepam which is responsible for the therapeutic effects of prazepam.
Pinazepam is a benzodiazepine drug. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties.
Camazepam is a benzodiazepine psychoactive drug, marketed under the brand names Albego, Limpidon and Paxor. It is the dimethyl carbamate ester of temazepam, a metabolite of diazepam. While it possesses anxiolytic, anticonvulsant, skeletal muscle relaxant and hypnotic properties it differs from other benzodiazepines in that its anxiolytic properties are particularly prominent but has comparatively limited anticonvulsant, hypnotic and skeletal muscle relaxant properties.
Fludiazepam, marketed under the brand name Erispan (エリスパン) is a potent benzodiazepine and 2ʹ-fluoro derivative of diazepam, originally developed by Hoffman-La Roche in the 1960s. It is marketed in Japan and Taiwan. It exerts its pharmacological properties via enhancement of GABAergic inhibition. Fludiazepam has 4 times more binding affinity for benzodiazepine receptors than diazepam. It possesses anxiolytic, anticonvulsant, sedative, hypnotic and skeletal muscle relaxant properties. Fludiazepam has been used recreationally.
Clotiazepam is a thienodiazepine drug which is a benzodiazepine analog. The clotiazepam molecule differs from benzodiazepines in that the benzene ring has been replaced by a thiophene ring. It possesses anxiolytic, skeletal muscle relaxant, anticonvulsant, sedative properties. Stage 2 NREM sleep is significantly increased by clotiazepam.
Tetrazepam is a benzodiazepine derivative with anticonvulsant, anxiolytic, muscle relaxant and slightly hypnotic properties. It was formerly used mainly in Austria, France, Belgium, Germany and Spain to treat muscle spasm, anxiety disorders such as panic attacks, or more rarely to treat depression, premenstrual syndrome or agoraphobia. Tetrazepam has relatively little sedative effect at low doses while still producing useful muscle relaxation and anxiety relief. The Co-ordination Group for Mutual Recognition and Decentralised Procedures-Human endorsed the Pharmacovigilance Risk Assessment Committee (PRAC) recommendation to suspend the marketing authorisations of tetrazepam-containing medicines across the European Union (EU) in April 2013. The European Commission has confirmed the suspension of the marketing authorisations for Tetrazepam in Europe because of cutaneous toxicity, effective from the 1 August 2013.
Cyprazepam is a drug which is a sedative-hypnotic benzodiazepine derivative. It has anxiolytic properties, and presumably also has hypnotic, skeletal muscle relaxant, anticonvulsant and amnestic properties.
Flutazolam is a drug which is a benzodiazepine derivative. It was invented in Japan, and this is the main country in which it has been used medically. It has sedative, muscle relaxant, anticonvulsant, and anxiolytic effects similar to those produced by other benzodiazepine derivatives, and though it is around the same potency as diazepam, it produces a more marked sedation and impaired coordination. It is indicated for the treatment of insomnia. Its major active metabolite is n-desalkylflurazepam, also known as norflurazepam, which is also a principal metabolite of flurazepam. While flutazolam has a very short half-life of only 3.5 hours, n-desalkylflurazepam has a long half-life of between 47–100 hours.
Metaclazepam is a drug which is a benzodiazepine derivative. It is a relatively selective anxiolytic with less sedative or muscle relaxant properties than other benzodiazepines such as diazepam or bromazepam. It has an active metabolite N-desmethylmetaclazepam, which is the main metabolite of metaclazepam. There is no significant difference in metabolism between younger and older individuals.
Girisopam is a drug which is a 2,3-benzodiazepine derivative, related to tofisopam and zometapine. It has selective anxiolytic action with no sedative, anticonvulsant or muscle relaxant effects.
Y-23684 is an anxiolytic drug with a novel chemical structure, which is used in scientific research. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.
Clazolam (SAH-1123), also referred to as isoquinazepon, is a drug which is a fused benzodiazepine and tetrahydroisoquinoline derivative. It was developed in the 1960s but was never marketed. It possesses anxiolytic effects and is also claimed to have antidepressant properties.
Diclazepam (Ro5-3448), also known as chlorodiazepam and 2'-chloro-diazepam, is a benzodiazepine and functional analog of diazepam. It was first synthesized by Leo Sternbach and his team at Hoffman-La Roche in 1960. It is not currently approved for use as a medication, but rather sold as an unscheduled substance. Efficacy and safety have not been tested in humans.
Flubromazolam (JYI-73) is a triazolobenzodiazepine (TBZD), which are benzodiazepine (BZD) derivatives. Flubromazolam is reputed to be highly potent, and concerns have been raised that clonazolam and flubromazolam in particular may pose comparatively higher risks than other designer benzodiazepines, due to their ability to produce strong sedation and amnesia at oral doses of as little as 0.5 mg. Life-threatening adverse reactions have been observed at doses of only 3 mg of flubromazolam.
Ro20-8065 (8-Chloronorflurazepam) is a benzodiazepine derivative with anticonvulsant and muscle relaxant effects, which has been sold as a designer drug.
Ro07-5220 (6'-Chlorodiclazepam) is a benzodiazepine derivative with sedative, anxiolytic, anticonvulsant and muscle relaxant effects, which has been sold as a designer drug.
