LY379268, an mGluR2/3 agonist, reduced breakpoints for cocaine by 40%.
Phenmetrazine, a dopamine releaser, reduced breakpoints for cocaine by about 25% maximum.
The combination of the two drugs showed a supra-additive effect in reducing breakpoints for cocaine by as much as 70%.
Neither LY379268 nor phenmetrazine, showed any nonspecific locomotor effects.