Blood Pressure Drug May Ease Severe Cocaine Withdrawal
"We can block some of those symptoms to make it easier for patients to resist cravings," Kampman says.
Kampman acknowledges that the results need to be repeated in much larger trials. But if Inderal proves to be successful, it could provide a new tool to treat the most difficult patients.
"What we would hope to do is identify the 40% of patients who have the most severe withdrawal symptoms and treat them with the drug," Kampman says. "
The work with Inderal follows similar studies Kampman has done in cocaine-addicted patients using another agent known as Symmetrel. That drug is commonly used in treating influenza and has also been found useful in treating Parkinson's disease.
In a study published in the Journal of Drug and Alcohol Dependence in 1996, Symmetrel was found to have no effect on cocaine addiction. But when Kampman and fellow researchers took a second look at the drug, they found a result similar to what they found with Inderal: The patients with the most severe withdrawal symptoms had in fact benefited from Symmetrel.
Those later results were published in the December 2000 edition of the American Journal of Psychiatry.
Kampman explains that when people use cocaine, levels of a chemical called dopamine are increased in an area of the brain researchers call "the pleasure center." The effect creates a sense of euphoria -- the high that users seek.
"If you use enough cocaine then abruptly stop, the levels of dopamine decrease significantly, causing severe withdrawal," he says.
Symmetrel is believed to work by elevating levels of dopamine. By treating patients with the drug, Kampman says, the dopamine "crash" can be cushioned and symptoms of withdrawal made less painful.
In future studies, Kampman and colleagues hope to try both medications in patients who have the most severe withdrawal symptoms. Because Inderal and Symmetrel appear to have similar effects but work through different mechanisms, Kampman hopes that two drugs, used in combination, may be better than one.
"Severity of withdrawal symptoms often disrupts treatment even in patients who are motivated to stop using cocaine," says psychiatrist Bert Pepper, MD, who reviewed the report on Inderal for WebMD. "It is very clear that in cocaine dependence we are dealing with a physical addiction that is much more powerful than motivation."