an agent that reduces tension in voluntary muscles. Drugs such as baclofen, dantrolene, and diazepam are used to relieve skeletal muscular spasms in various spastic conditions, parkinsonism, and tetanus. The drugs used to relax voluntary muscles during the administration of anaesthetics in surgical operations act by blocking the transmission of impulses at neuromuscular junctions. Nondepolarizing muscle relaxants, e.g. atracurium besilate, gallamine, and pancuronium, bind to receptor sites normally occupied by acetylcholine; depolarizing muscle relaxants, e.g. suxamethonium, mimic the action of acetylcholine but depolarization is prolonged.
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an agent that specifically aids in reducing muscle tension, as those acting at the polysynaptic neurons of motor nerves (e.g., meprobamate) or at the neuromuscular junction (curare and related compounds); see also neuromuscular blocking agent, under agent.Medical dictionary. 2011.