Modest oral doses of MDMA increase heart rate, blood pressure, and myocardial oxygen consumption in a magnitude similar to dobutamine, 20 to 40 microg/kg per minute. In contrast to dobutamine, MDMA has no measurable inotropic effects.
Sublingual buprenorphine is a promising new treatment for opiate dependence, but its opioid agonist effects pose a risk for parenteral abuse. A formulation combining buprenorphine with the opiate antagonist naloxone could discourage such abuse. The effects of three intravenous (IV) buprenorphine and naloxone combinations on agonist effects and withdrawal signs and symptoms were examined in 12 opiate-dependent subjects. Following stabilization on a daily dose of 60 mg morphine intramuscularly, subjects were challenged with IV doses of buprenorphine alone (2 mg) or in combination with naloxone in ratios of 2:1, 4:1, and 8:1 (1, 0.5, or 0.25 mg naloxone), morphine alone (15 mg) or placebo. Buprenorphine alone did not precipitate withdrawal and had agonist effects similar to morphine. A naloxone dose-dependent increase in opiate withdrawal signs and symptoms and a decrease in opioid agonist effects occurred after all drug combinations. Buprenorphine with naloxone in ratios of 2:1 and 4:1 produced moderate to high increases in global opiate withdrawal, bad drug effect, and sickness. These dose ratios also decreased the pleasurable effects and estimated street value of buprenorphine, thereby suggesting a low abuse liability. The dose ratio of 8:1 produced only mild withdrawal symptoms. Dose combinations at 2:1 and 4:1 ratios may be useful in treating opiate dependence.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.