Description

Thiocolchicoside is a semi-synthetic muscle relaxant derived from colchicoside, a naturally occurring glycoside found in the Gloriosa superba (Superba lily). It is a centrally acting agent used to treat painful muscle contractures and spasms. It is available in various formulations, including oral tablets, capsules, and topical creams, as well as an injectable form for more severe cases.

Indication

Thiocolchicoside is indicated for the symptomatic treatment of painful muscle spasms and contractures, particularly those associated with various orthopedic, traumatic, and rheumatological conditions. Its main indications include:

• Torticollis (Wry Neck): To relieve the painful muscle spasms in the neck.

• Back Pain: Used to treat muscle spasms associated with conditions like lumbago, sciatica, and chronic back pain.

• Traumatology and Orthopedics: To relieve muscle spasms following traumatic injuries or orthopedic surgical procedures.

• Rheumatology: To manage muscle spasms that are a component of rheumatic diseases.

Mechanism of Action

The mechanism of action of Thiocolchicoside is primarily centered on its action in the central nervous system, particularly at the spinal cord and supraspinal levels. It does not act at the neuromuscular junction like some other muscle relaxants.

1. GABA Agonism: Thiocolchicoside acts as a selective GABA (gamma-aminobutyric acid) receptor agonist, specifically at the GABAA​ receptors. GABA is the primary inhibitory neurotransmitter in the central nervous system. By mimicking the action of GABA, thiocolchicoside increases the inhibitory tone on motor neurons in the spinal cord. This results in a reduction of muscle contractions and spasticity.

2. Glycine Receptor Agonism: Thiocolchicoside also has a direct inhibitory effect on the central nervous system by acting as a glycine receptor agonist. Glycine is another important inhibitory neurotransmitter in the spinal cord and brainstem. Its agonistic action further contributes to the reduction of muscle tone and spasms.
3. No Curare-like Effect: It is important to note that thiocolchicoside does not have a curare-like effect, meaning it does not cause paralysis of the skeletal muscles. Its action is to reduce muscle tone and contractures by modulating the central nervous system’s control over muscle movement.

4. Anti-inflammatory and Analgesic Effects (Secondary): While its primary mechanism is muscle relaxation, thiocolchicoside also has some anti-inflammatory and analgesic properties, which can help to reduce pain associated with muscle spasms.