“We have found that cocaine’s effects on the cardiovascular system can be reversed by the use of a drug called dexmedetomidine, which is currently approved by the FDA for anesthetic purposes in operating rooms or intensive care units,” said Dr Wanpen Vongpatanasin, associate professor of internal medicine and senior author of the study.
Researchers used dexmedetomidine to test whether cocaine’s effect on the cardiovascular system could be muted. They found that the drug was effective in reversing the actions of cocaine on heart rate, blood pressure and vascular resistance in the skin by interfering with the ability of cocaine to increase nerve activity.
“Typically, patients with cocaine overdoses in the emergency room are treated with nitroglycerin, sedatives such as Valium, and some blood-pressure medications such as calcium channel blockers and some beta blockers,” Dr Vongpatanasin said. “However, the standard treatments don’t alleviate all of the adverse effects of cocaine on the heart, blood pressure and central nervous system.”
The study examined results from 22 healthy adults who reported to have never used cocaine. The investigators administered a small, medically approved dose of cocaine nose drops to the study participants, which doubled their sympathetic nerve activity, part of the body’s ‘automatic’ response system that becomes more active during times of stress. Participants experienced increases in several cardiovascular parameters, including heart rate, blood pressure and resistance to blood flow in the skin.
Microelectrodes, similar to acupuncture needles, were used to record sympathetic nerve activity following doses of intranasal cocaine.
Research subjects who were treated with dexmedetomidine had a decrease in sympathetic nerve activity as well as in all three cardiovascular parameters, which returned to baseline levels measured before administration of cocaine. Dexmedetomidine proved to be more effective than intravenous saline, which was used as a placebo in another group of study participants.
Further research is needed, the study authors said, to determine whether the treatment would be effective for acute cocaine overdose in the emergency room and to gauge whether it would be effective in reversing cocaine-induced constriction of the coronary vessels to the same degree it does in skin vessels.