Drugs used for Muscle Spasm

Acute Muscle contusion-sprain

(physical therapy; cold packs; alternate with heat)



These drugs have different sites of action

Dantrolene: acts directly on skeletal muscle to prevent the release calcium from the sarcoplasmic reticulum and thus prevent contraction; it is fairly specific for skeletal muscle

Diazepam: variety of pharmacological features, can act on specific receptors to inhibit the reflex mediated through the spinal cord that mediates motor impulses to the skeletal muscles.

Baclofen: acts on a specific GABA receptor as an agonist.


These drugs basically act on specific receptors in the spinal cord, but that doesn’t necessarily mean that they affect the motor neurons. These drugs DO NOT affect nerve conduction, contrasted with local anesthetics. In fact, in severe spasm associated with pain a local injection of local anesthetic will relieve the spasm and the pain. Of course you consider that as a last option.


There are of course other agents. The motor cortex sends signals down through the spinal cord to the alpha motor neuron; theoretically you could have drugs active at the motor cortex pyramidal system.

Category: Pharmacology Notes