Sandra Comer, Ph.D.
Dr. Sandra Comer is an Associate Professor of Clinical Neurobiology in the
Department of Psychiatry at the College of Physicians and Surgeons of
Columbia University, and a Research Scientist at the New York State
Psychiatric Institute. Dr. Comer received her undergraduate degree at
Vanderbilt University (1987), and completed her graduate training at the
University of Michigan, where she received her Ph.D. (1992) studying the
effects of opioid drugs in animal models of analgesia and subjective effects
in the laboratory of Dr. James H. Woods. Following graduate school, Dr.
Comer completed a two year post-doctoral fellowship at the University of
Minnesota, Minneapolis. There she received training in preclinical animal
models of cocaine self-administration in rodents and non-human primates in
the laboratory of Dr. Marilyn Carroll. In 1993, Dr. Comer began working at
the Division of Substance Abuse at Columbia University. Here she received
training in human preclinical studies under the mentorship of Dr. Marian
Fischman and Dr. Richard Foltin. Since coming to Columbia, Dr. Comer has
focussed on the development and testing of novel approaches to the treatment
of opioid dependence, and the influence of sex differences and hormonal
influences on responses to pain and opioid medications.

E-Mail: sdc10@columbia.edu

Current Research Activities
1. Opioid Pharmacotherapy: A primary focus of the Division of Substance Abuse is to investigate potential treatment medications for opioid dependence using a preclinical human laboratory model. The basic tenet of this model is that in order to determine the potential utility of a medication for opioid dependence, the effect of the medication on drug-taking must be studied directly. Dr. Comer has investigated the effects of selective opioid receptor antagonists (naltrexone) and partial agonists (buprenorphine) on a range of opioid effects (self-administration, subjective ratings, physiological measures). She and her colleagues have shown that a depot formulation of naltrexone produces a dose-dependent antagonism of heroin’s effects for up to a month. More recently, Dr. Comer and colleagues have been investigating the effects of memantine, an antagonist at N-methyl-D-aspartate receptors, which may prove to be an effective treatment for opioid dependence by decreasing both craving for heroin and the euphoric effects produced by heroin. In addition, the effectiveness of buprenorphine and the buprenorphine/naloxone combination in reducing heroin’s effects have been investigated. Another line of research has examined the conditions under which buprenorphine itself may be reinforcing. In these studies, individuals were given the opportunity to self-administer buprenorphine alone and buprenorphine in combination with naloxone. The reinforcing effects of buprenorphine were also compared to those of the full opioid agonist, methadone. These studies were all conducted in opioid dependent individuals with the aim of understanding and developing new medications for the treatment of opioid dependence.

2. Sex Differences and Hormonal Influences on Pain Responsivity: Dr. Comer and colleagues have developed a laboratory model to investigate the responses to experimentally-induced painful stimuli in men, normally-menstruating women, and women maintained on monophasic oral contraceptives. Previous studies have demonstrated that some opioid medications may be more effective and longer lasting in women, compared to men, but this effect has yet to be fully characterized in humans. Specifically, the effects of morphine, the prototypic agonist at the mu subtype of opioid receptor, and butorphanol, a mixed action opioid with effects at the kappa subtype of opioid receptor, are being studied. Dr. Comer was recently awarded another grant to extend this line of research by investigating the conditions under which prescription opioid medications may be abused. Self-administration of oxycodone and codeine will be compared in drug abusers and non-drug abusers under conditions of experimentally-induced pain or no pain. This research will potentially shed light on the populations of individuals who may abuse prescription opioids, and the conditions under which prescription opioids may be abused.

Training Opportunities
Dr. Comer has mentored graduate students completing thesis projects, and contributes to the training of postdoctoral research funded through Dr. Herbert Kleber’s Postdoctoral Fellowship.

Selected Peer-reviewed Publications
Comer, S.D., Collins, E.D., Fischman, M.W.: Buprenorphine sublingual tablets: Effects on IV heroin self-administration by humans. Psychopharmacology 154: 28-37, 2001.

Comer, S.D., Collins, E.D., Kleber, H.D., Nuwayser, E.S., Kerrigan J.H., and Fischman, M.W.: Depot naltrexone: Long-lasting antagonism of the effects of heroin in humans. Psychopharmacology 159: 351-360, 2002.

Comer, S.D. and Collins, E.D.: Self-administration of intravenous buprenorphine and the buprenorphine/naloxone combination by recently detoxified heroin abusers. J. Pharmacol. Exp. Ther. 301(1): 266-276, 2002.