Effects of 3,4-methylenedioxypyrovalerone (MDPV) pre-exposure on the aversive effects of MDPV, cocaine and lithium chloride: Implications for abuse vulnerability

- 3,4-Methylenedioxypyrovalerone (MDPV), cocaine and emetic lithium chloride (LiCl) induced significant and comparable taste avoidance.
- MDPV history attenuated taste avoidance induced by MDPV and cocaine.
- MDPV history had no effect on LiCl-induced taste avoidance.
- Such attenuation may increase the abuse potential of MDPV and related drugs.

BackgroundDrug use is thought to be a balance of the rewarding and aversive effects of drugs. Understanding how various factors impact these properties and their relative balance may provide insight into their abuse potential. In this context, the present study attempted to evaluate the effects of drug history on the aversive effects of 3,4-methylenedioxypyrovalerone (MDPV), one of a variety of synthetic cathinones (collectively known as “bath salts”).MethodsDifferent groups of male Sprague-Dawley rats were exposed to either vehicle or MDPV (1.8 mg/kg) once every fourth day for five total injections prior to taste avoidance conditioning in which a novel saccharin solution was repeatedly paired with either vehicle, MDPV (1.8 mg/kg), the related psychostimulant cocaine (18 mg/kg) or the emetic lithium chloride (LiCl) (13.65 mg/kg).ResultsIn animals pre-exposed to vehicle, all three drugs induced significant and comparable taste avoidance relative to animals injected with vehicle during conditioning. MDPV pre-exposure attenuated the avoidance induced by both MDPV and cocaine (greater attenuation for MDPV than cocaine), but had no effect on that induced by LiCl.ConclusionsThese findings suggest that a history of MDPV use may reduce or attenuate MDPV and cocaine's (but not LiCl's) aversive effects. The implications for such changes in MDPV's aversive effects to its potential use and abuse were discussed.