Kevin Hill, MD, MHS

TB Drug Could Aid Smoking Cessation

Kevin Hill, MD, MHS is investigating whether an antibiotic already approved by the U.S. Food and Drug Administration for the treatment of tuberculosis will help people quit smoking. Preliminary evidence suggests that the drug, D-cycloserine (DCS), may be able to help smokers make better use of their counseling sessions by enhancing their ability to learn how to avoid smoking.

“If we find this drug is effective in helping people to quit smoking, the translation into practice would be relatively quick, since this is a drug that is already readily available.”
There is a great need for more effective treatments for smoking cessation, Dr. Hill says. “Success rates for currently available treatments are, at best, around 35 percent at six months.” he notes. “If we could take the best available treatments, such as nicotine replacement therapy (NRT) and cognitive behavioral therapy (CBT), and magnify their effects, it would have a tremendous impact upon millions of smokers who want to quit. If we could boost success rates by an additional 15 percent, for example, that would mean half of smokers would experience some type of success in quitting smoking, and then we’d have a lot more people willing to get into treatment.”

CBT is a type of talk therapy that is used to treat nicotine dependence, as well as a number of other conditions including panic disorder and general anxiety disorder. In CBT for smoking, patients work with their therapist on how to handle high-risk smoking situations so that gradually they will become desensitized to the feelings of craving that occur whenever they are exposed to smoking cues. DCS enhances this process, called extinction learning, by working on receptors in the brain called NMDA receptors, which are associated with learning. “DCS works on these receptors by dampening the reaction, making you more likely to be able to dissociate a cue, such as seeing a cigarette, with a response of wanting to smoke,” Dr. Hill says.

He is thrilled to have received an American Lung Association grant. “We’ve been trying to secure funding for this research for several years, and now that we have it, we are pushing full speed ahead with the study. If we find this drug is effective in helping people to quit smoking, the translation into practice would be relatively quick, since this is a drug that is already readily available.”

Dr. Hill will also study the effects of DCS on learning and memory, through neuropsychological tests. “If the drug is enhancing the extinction learning process, we can use neuropsychological testing to see why it is working,” he says. “That information may help us determine if particular patients are more responsive than others to this treatment.”