I'm not sure I'd class that as "abuse". I guess it depends of the extent of the damage to his hands. Lots of guys shot up their hands. Max Baer, Muhammad Ali, many many more. Maybe most of them sometime or another. Did Jeff fight the second fight ?
I beleive Jeffries was anxious to fulfill his contract ,as it was a big chance for him to display his wares,he was not seeking any advantage ,in fact he should be commended for trying to continue although injured. He received an unfair panning in the press ,the day after the affair . Your old mate John L used to imbibe between rounds, sometimes Brandy ,sometimes Champagne. In one fight he was given gin and water ,and duly vomited, a wag said "John is bringing up the water." He must have been well pissed by the time he finished off Kilrain.
The second fight was not alowed to go ahead by the fight doctor. It is true that Jeffries was not seeking advantage, but using cocaine would have got him DQd today.
I think its more rampant than anyone thinks. When I was involved with the amatuers in the early 90's I cant tell you how many showed up to fight stoned on weed. Incredible really.
Lew Jenkins admitted to entering the ring so drunk on numerous occasions that he'd nearly be falling over. Then he'd drink more in his corner.
Early in his career Paul Banke entered the ring drunk and was knocked out early. I think Zack Padilla was high on coke during several of his earlier fights.
I doubt it qualifies what you are looking for as far as substance abuse goes during a fight, but Yaqui Lopez's co-trainer Hank Pericle claims that there was a rule prohibiting smelling salts in their second fight with Saad Muhammad and while he followed that rule he found out that Saad's camp did not. He blamed their usage of it, combined with his following the rule as the reason why Matt got his 2nd wind and Yaqui did not. On the Miricle Matt Franklin/Saad Muhammad front...there are reports that when he was cut in his first fight with Conteh, the ointment that was used to stop his cut got on his gloves and ultimately into the eyes Conteh. The WBC suspended his cutman Adolph Ritaccio for a year and mandated an immediate rematch. I don't think thats what you were looking for, but I was doing some reading on Franklin/Muhammad and came across both of those reports.