Green’s Dictionary of Slang

1. amphetamines.

1966		J. Mills Panic in Needle Park (1971) 41: He was on amphetamines, stimulants, and had been shooting bombitas, small glass ampules of a drug called Desoxyn.
1971		E.E. Landy Underground Dict. (1972) 38: bombita. Methedrine.
1980		(con. 1940s–60s) H. Huncke ‘Joseph Martinez’ in Eve. Sun Turned Crimson (1998) 219: What’s that rash on your face? You take bombitas?
1981		D.E. Miller Bk of Jargon 337: bombita, bombido: Desoxyn or other amphetamines.
2001		ONDCP Street Terms 4: Bombita (Spanish) — [...] amphetamine.
2009		J. Stahl Pain Killers 286: He say it was crank. But I don’t know . . . it ain’t like normal bombita.

2. a mix of heroin and cocaine.

1969		R.R. Lingeman Drugs from A to Z (1970) 49: (2) by extension, perhaps any amphetamine in solution. Addicts often inject amphetamines in conjunction with their heroin injection to enhance the rush.
2001		ONDCP Street Terms 4: Bombita (Spanish) — Heroin.

3. a depressant.

2001

ONDCP Street Terms 4: Bombita (Spanish) — [...] depressants.