Free-base cocaine smoking.

Six healthy male, paid subjects smoked 50 mg of free-base cocaine in a specially designed glass pipe under a rigidly controlled smoking protocol. The method of heating the pipe and the temperature that produced the most efficient and consistent vaporization of the drug had been determined experimentally. The psychological and cardiovascular effects of smoking free-base cocaine were recorded. Approximately 26% of th original material was recovered from the pipe after smoking. Simulated smoking experiments in vitro indicated that only 44% of the material not trapped in the pipe was cocaine and that over 90% of this cocaine was delivered during the first four puffs (i.e., during the first 2 min of simulated smoking). These findings indicate that of the original 50 mg of cocaine free base placed in the pipe's bowl, only 32% could have been inhaled (16.3 +/- 0.6 mg). The cocaine free base inhaled induced psychological and cardiovascular effects similar to, or slightly more intense and pleasurable than, the effects of 20 mg of cocaine HCl (18 mg of cocaine base) taken intravenously by the same subjects and also induced a slightly more intense craving for another dose.