Pharmacological effects of methamphetamine and other stimulants via inhalation exposure

The effects of methamphetamine-HCl, methcathinone-HCl, cocaine and ephedrin e on locomotor stimulation were compared between inhalation exposure and i. v. injection in mice. Methamphetamine-HCl was readily volatilized upon heat ing at 300 degrees C in a glass pipe with only trace amounts of amphetamine being produced. The ED50 dose (9.4 and 6.5 mu mol/kg for inhalation exposu re and i.v. injections, respectively) and biodisposition of methamphetamine -HCl were similar for both routes of administration. Methcathinone-HCl and cocaine were readily volatilized. Their dose response profiles also appeare d similar for both routes of administration. Ephedrine did not appear to be easily volatilized and was only effective in stimulating locomotor activit y after i.v. administration. These findings indicate that inhalation exposu re to methamphetamine-HCl, cocaine and methcathinone possess similar pharma cological characteristics as the i.v. route of administration. In particula r, this model may have implications in predicting the pharmacological activ ity of various stimulants via the inhalation route of administration. (C) 1 999 Elsevier Science Ireland Ltd. All rights reserved.