I found this description of the book, in English:
The jungle has it's own truth: Lyric, Violent, Erotic, Primeval
To the warrior-priests of the Venezuelan forest people, the drug is a sacred substance: part pain, part pleasure. Skullflush is a psychic whiplash, an exhilarating gateway to an advanced consciousness beyond time and species. For millennia, the primative tribe has kept it's secret safe from civilation. Until a ruthless drug lord skips with a stolen six-kilo stash - intending to peddle his prize in the nightclubs of Florida.
Tampa's thrill seekers are eager to sample the pale green powder. But generations of urbanized decadence have left them jaded, shallow, and weak... too weak to handle the drug's mystic high. The ancient rain-forest chemistry warps bone, muscle, and sinew in their city soft bodies, setting free the fierce power of man's basic nature.
Hope that helps :)