Pharmacodynamics of Chlorzoxazone

Chlorzoxazone is a muscle relaxant. It acts by blocking nerve impulses or pain sensations that are sent to brain. Typically, it is used together with rest and physical therapy to treat skeletal muscle conditions such as pain or injury. Chlorzoxazone, 5-chloro-2-benzoxazolione, is synthesized by a heterocyclization reaction of 2-amino-4-chlorophenol with phosgene. Skeletal muscle relaxants have conventionally been classified into one group; however, they are actually a heterogeneous group of medications commonly used to treat two different types of underlying conditions – spasticity from upper motor neuron syndromes and muscular pain or spasms from peripheral musculoskeletal conditions. Medications classified as skeletal muscle relaxants are baclofen, carisoprodol, chlorzoxazone, cyclobenzaprine, dantrolene, metaxalone, methocarbamol, orphenadrine, and tizanidine. These drugs may impair mental and/or physical abilities required for driving vehicles. 

Properties

Chlorzoxazone is a white to off-white solid. It is soluble in organic solvents such as ethanol, methanol, and dimethyl sulfoxide (DMSO).

Uses

Chlorzoxazone is used as a centrally acting skeletal muscle relaxant and as an analgesic. It is also a strong oxidizing agent.

Pharmacodynamics

Chlorzoxazone is a centrally-acting agent for painful musculoskeletal conditions. Data available from animal experiments as well as human study indicate that chlorzoxazone acts primarily at the level of the spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex a.c. involved in producing and maintaining skeletal muscle spasm of varied etiology. The clinical result is a reduction of the skeletal muscle spasm with relief of pain and increased mobility of the involved muscles.