Stimulant Summit: Promising signs, but no guarantees, for a medication development

As concerns about stimulant dependence re-emerge in the consciousness of addiction professionals, murmurs about the absence of approved medication treatments grow into a collective roar. A University of Kentucky research leader speaking on day one of the National Cocaine. Meth & Stimulant Summit offered several personal examples to illustrate why the path to medication discovery likely will remain littered with roadblocks.

Craig R. Rush, PhD, a professor in the university's Department of Behavioral Science, cited preliminary research that, while showing promise for various drug combinations for cocaine use, has failed to win support from funders of what would be more conclusive randomized trials.

“I wish I could generate more enthusiasm at [the National Institute on Drug Abuse] for these drug combinations, but they have made it crystal clear that they need to see a regulatory pathway [to approval],” Rush said. The problem lies largely in drug companies' reluctance to have a drug that is already approved for another disorder become associated with addiction treatment as well.

Rush, who is vice chair for research in psychiatry at the university, sees significant potential in drug combinations already used to treat conditions with similar neurobiological underpinnings to cocaine adidction, such as obesity. He has been involved in small studies of combinations of bupropion and naltrexone (marketed as Contrave for obesity) and topiramate and phentermine (sold as Qsymia), but in both cases proposals for Phase II studies were not funded.

“There are lots of advantages to repurposing available drugs,” said Rush, with appetite suppressants a promising category.

Given the gravity of the growing stimulant problem, “I don't feel like we've got a dozen years to be identifying a novel molecule.” Besides, interest in the pharmaceutical industry over new drug development for cocaine dependence has been sparse.

Clamoring for options

Rush told a breakout session audience at the Institute for the Advancement of Behavioral Healthcare's inaugural Stimulant Summit conference near Fort Lauderdale, Fla., that at a recent grand rounds he attended in West Virginia, there was a chorus of, “We need something for meth.” His short answer: “We're working on it. It takes time.”

He expressed no surprise that cocaine and/or methamphetamine overdose numbers are now rising significantly in many parts of the country. “Drug use and abuse is cyclical,” he said. While the opioid crisis clearly merits the attention it has received, “We have to pay attention to these other drugs of abuse as well,” Rush said.

Moreover, use of any individual drug does not tend to occur in isolation, he said. “In my 30 years of work, I would say I have never seen 'pure' cocaine abuse. They all drink, they all smoke tobacco cigarettes, and they use other drugs,” he said.

A physician in the session audience asked Rush a question about off-label use of drugs for cocaine addiction treatment, and confirmed the seriousness of the concern about methamphetamine in his community. The doctor said that in his area of northwest Pennsylvania, there is now a crystal meth crisis “that is way above our opioid use.”