Sodium bicarb (judicious doses)
Cessation of offending drug
Normal saline
Anecdotal evidence to support Riboflavin (50mg/day), and/or thiamine (100mg BID) 
Stop all anti-retrovirals until lactate normalization
Consider antioixidant supplementation to reduce oxidative stress and hyperlactemia
HAART-induced lactic acidosis
Sepsis
Metformin-associated lactic acidosis
Ischemia
Infectious mononucleosis
HIV neurologic complications
Cerebral edema in DKA
Toxoplasmosis