Nicoboxil

In particular, nicoboxil is considered a rubefacient. However, the specific mechanism of action by which rubefacients like nicoboxil elicit pharmacologic effects has not yet been formally elucidated. Nevertheless, it is generally proposed that rubefacients cause irritation of the skin when applied topically, and are believed to alleviate pain in muscles, joints, tendons, and other musculoskeletal pains in the extremities by counter-irritation. This specific term, 'counter-irritant', derives from the fact that rubefacients can cause a reddening of the skin by causing the blood vessels of the skin to dilate, which gives a soothing feeling of warmth. In essence, the term largely refers to the notion that irritation of the sensory nerve endings alters or offsets pain in the underlying muscle or joints that are innervated by the same nerves.

In fact, the vasodilation effect of rubefacients like nicoboxil has been considered the result of nerve conduction mechanisms as early as the late 1950s when certain studies demonstrated that the concomitant application of xylocaine could counteract or prevent the vasolidator response to rubefacients in 50% of such related experiments.