I'm prettty sure that stills were not invented for over a thousand years. I can't think of any drugs they had that would have been worth using. Maybe Bulgarian anaesthesia,
a knock on noggin with a mallet. The Delphic oracle is said to have inhaled gases with aome anaesthetic properties, but
no way that could have helped Marius.

P.S. I found a site claiming Aristotle knew about distilling.Still don't think it could have helped our hero.
"The process of distillation is old enough to have been mentioned by Aristotle—who lived from 384 to 322 B.C.—but Pliny the Elder (A.D. 23–79), a Roman, first described a still. At its most basic, a still consists of a retort, in which the liquid to be distilled is heated; a coil, called a condenser, at the top of the still, to cool and condense the vapor; and a receiver, a vessel that collects the distillate. Over the years, various elaborate industrial stills have been created, but they all consist essentially of the same three parts. "