Benzethonium chloride

From Memory Alpha, the free Star Trek reference

Benzethonium chloride was a painkiller used in hospitals on Risa.

In 2151, following a rock climbing accident, Ensign Travis Mayweather was given bezethonium chloride at a Risan hospital. He turned out to be highly allergic to it, and suffered from swelling that threatened to constrict his airway. (ENT: "Two Days and Two Nights")

Benzethonium chloride is, in actuality, an antiseptic solution commonly found in handwash.