Thiocolchicoside

Thiocolchicoside is a muscle relaxant with anti-inflammatory and analgesic effects. Thiocolchicoside is a semisynthetic derivative of colchicine, a natural anti-inflammatory substance extracted from the flower seeds of the autumn crocus (Colchicum autumnale). The substance is used to treat orthopedic, traumatic, and rheumatologic conditions. It is also used as an adjuvant in the treatment of painful muscle contractions and acute spinal disorders in adults and adolescents 16 years of age and older.

Due to its pronounced and sometimes serious side effects, the EMA (European medicines agency) recommends thiocolchicoside only as an adjuvant in acute muscle spasms and advises against longer-term treatment.

Pharmacodynamics

Thiocolchicoside is a synthetic sulfur derivative of colchicine. It selectively binds to so-called GABA_A receptors and therefore mimics the action of the naturally occurring neurotransmitter gamma-aminobutyric acid (GABA) in the body. GABA-ergic neurons are involved in processes such as muscle relaxation, anxiety relief, sedation and anesthesia. GABA may also regulate heart rate and blood pressure.

Pharmacokinetics

Thiocolchicoside is rapidly absorbed after oral administration. Oral bioavailability is approximately 25%. It is metabolized in the liver and excreted in the form of its three major metabolites either in feces (~79%) or urine (20%). The plasma half-life is approximately 7 hours.

Side effects

Side effects of thiocolchicoside may include nausea, allergic reactions, and vasovagal syncope. Liver damage, pancreatitis, seizures, hematopoietic disorders, severe skin disorders, rhabdomyolysis, and reproductive disorders have been reported in rare cases.

Contraindications

It has a strong convulsion-inducing effect and should not be administered to individuals prone to seizures. This includes, for example, people suffering from epilepsy.

Thiocolchicoside is teratogenic in experimental animals and also damages chromosomes. There are insufficient data in humans to clearly indicate a teratogenic effect. However, use in pregnancy is not recommended due to lack of safety.