Thiocolchicoside 4 mg + Etoricoxib 60 mg

Any other selective COX-2 inhibitor ("coxib"), Etoricoxib selectively inhibits isoform 2 of the enzyme cyclooxygenase (COX-2). It has approximately 106-fold selectivity for COX-2 inhibition over COX-1. This reduces the generation of prostaglandins (PGs) from arachidonic acid. Among the different functions exerted by PGs, their role in the inflammation cascade should be highlighted.

Selective COX-2 inhibitors show less activity on COX-1 compared to traditional non-steroidal anti-inflammatory drugs (NSAID). This reduced activity is the cause of reduced gastrointestinal side effects, as demonstrated in several large clinical trials performed with different coxibs.

Thiocolchicoside, is a synthetic sulfur derivative of colchicoside, a naturally occurring glucoside contained in the Colchicum autumnale plant. Thiocolchicoside has a selective and potent affinity for g-aminobutyric acid A (GABA-A) receptors and acts on muscular contractures by activating the GABA inhibitory pathways thereby behaving as a potent muscle relaxant 18. Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the human cortex 11. GABAergic neurons are involved in myorelaxation, anxiolytic treatment, sedation, and anesthetics. GABA can also modulate heart rate and blood pressure.

It also has an affinity for the inhibitory glycine receptors (i.e., have glycomimetic and GABA mimetic activity), therefore acts as a muscle relaxant. Glycine is an inhibitory neurotransmitter and acts as an allosteric regulator of NMDA (N-methyl-D-aspartate) receptors. It is involved in the processing of motor and sensory data, thereby regulating movement, vision, and audition. Inhibitory neurotransmitter in spinal cord, allosteric regulator of NMDA receptors 19,12.

In one study, thiocolchicoside inhibited the function of recombinant human strychnine-sensitive glycine receptors composed of the alpha1 subunit with a potency (median inhibitory concentration of 47 microM) lower than that apparent with recombinant GABA(A) receptors. The drug also inhibited the function of human nicotinic acetylcholine receptors made of the alpha4 and beta2 subunits, however, this effect was partial and moreover only apparent at high concentrations. Thiocolchicoside demonstrated no effect on the function of 5-HT(3A) serotonin receptors 1