Increased homocysteine levels associated with sex and stress in the learned helplessness model of depression

Elevated levels of homocysteine (Hey) have been associated with major depressive (MD) illness. As human females show a higher predisposition towards depression, this study examined how Hey levels in rats are affected by sex and estrous cycle in the learned helplessness (LH) model of depression. Male and female rats in either estrus or diestrus were subjected to LH, with intervals of 4 days between the two stress tests and between tests and sacrifice, in order to accommodate the female estrous cycle. No differences were found in LH behavior between males and females at either estrous phase. Control Hcy levels were significantly lower in females than in males (-36%, P<.001), with no further differences between estrous and diestrus phases in females. Stress exposure increased plasma Hcy by approximately 26% in females, both in estrus and diestrus, but not in males. However, when behavioral responses to stress were considered, no association was found between increased Hcy levels and propensity to develop helpless behavior. Therefore, while male rats have higher basal Hcy levels than females, females appear to be more vulnerable than males to stress-induced elevations in Hey, although this did not correlate with behavioral responses to stress. Neither was this vulnerability influenced by estrous phase. These results imply that both stress and sex should be considered as risk factors for increased plasma Hey. (C) 2003 Elsevier Inc. All rights reserved.Ctr Addict & Mental Hlth, Neuroimaging Res Sect, Toronto, ON M5T 1R8, CanadaUniv Toronto, Dept Pharmacol, Toronto, ON, CanadaUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pediat, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, São Paulo, BrazilWeb of Scienc

A multicenter, primary care-based, open-label study to identify behaviors related to prescription opioid misuse, abuse, and diversion in opioid-experienced patients with chronic moderate-to-severe pain

Beatrice Setnik,1 Carl L Roland,1 Kenneth W Sommerville,1,2 Glenn C Pixton,1 Robert Berke,3,4 Anne Calkins,5 Veeraindar Goli1,2 1Pfizer Inc, 2Duke University Medical Center, Durham, NC, 3Family Health Medical Services PLLC, Mayville, NY, 4Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, NY, 5New York Spine &amp; Wellness Center, Syracuse, NY, USA Objective: To compare the investigator assessment of patient risk for prescription opioid misuse, abuse, and diversion with patient self-reports of these activities in a population with chronic pain. Methods: As a secondary objective of an open-label, multicenter, primary care-based clinical study to evaluate the success of converting opioid-experienced patients with chronic pain to morphine sulfate with sequestered naltrexone hydrochloride, risk for misuse, abuse, and diversion was assessed using two nonvalidated questionnaires: one was completed by the investigator and another by the patient (Self-Reported Misuse, Abuse, and Diversion [SR-MAD]). In addition, the validated Current Opioid Misuse Measure (COMM) test and urine drug test were used. Results: Of the 684 patients assessed by the investigators, 537 returned the self-assessment, SR-MAD. Most patients were assigned by the investigator as low risk for misuse (84.2%), abuse (89.3%), and diversion (94.3%). Of the patients who returned SR-MAD, 60% indicated having taken more opioids than prescribed and 10.9% reported chewing or crushing their opioids in the past. Of the patients who completed COMM, 40.6% were deemed as having aberrant behaviors. COMM results correlated with the risk levels from the investigator assessment. One-third of patients (33.8%) had at least one abnormal urine drug test result. Conclusion: More research is needed to better understand the gap between the investigator assessment of potential risk for misuse, abuse, and diversion and the actual extent of these behaviors among patients with chronic pain. Keywords: opioid, abuse, misuse, diversion, chronic pai

A multicenter, primary-care-based, open-label study to assess the success of converting opioid-experienced patients with chronic moderate-to-severe pain to morphine sulfate and naltrexone hydrochloride extended-release capsules using a standardized conversion guide

Beatrice Setnik,1 Carl L Roland,1 Kenneth W Sommerville,1,2 Glenn C Pixton,1 Robert Berke,3,4 Anne Calkins,5 Veeraindar Goli1,2 1Pfizer Inc, 2Duke University Medical Center, Durham, NC, USA; 3Family Health Medical Services PLLC, Mayville, 4Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, 5New York Spine &amp; Wellness Center, Syracuse, NY, USA Objective: To evaluate the conversion of opioid-experienced patients with chronic moderate-to-severe pain to extended-release morphine sulfate with sequestered naltrexone hydrochloride (MSN) using a standardized conversion guide. Methods: This open-label, single-arm study was conducted in 157 primary care centers in the United States. A total of 684 opioid-experienced adults with chronic moderate-to-severe pain were converted to oral administration of MSN from transdermal fentanyl and oral formulations of hydrocodone, hydromorphone, methadone, oxycodone, oxymorphone, and other morphine products using a standardized conversion guide. The primary endpoint was the percentage of patients achieving a stable MSN dose within a 6-week titration phase. Secondary endpoints included duration of time to stable dose, number of titration steps, safety and efficacy measures, and investigator assessment of conversion guide utility. Results: Of the 684 patients, 51.3% were converted to a stable dose of MSN (95% confidence interval: 47.5%, 55.1%). The mean (standard deviation) number of days to stable dose was 20 (8.94), and number of titration steps to stable dose was 2.4 (1.37). The majority of adverse events were mild/moderate and consistent with opioid therapy. Mean pain scores at stable dose decreased from baseline. Investigators were generally satisfied with the conversion guide and, in 94% of cases, reported they would use it again. Conclusion: Conversion to MSN treatment using the standardized MSN conversion guide was an attainable goal in approximately half of the population of opioid-experienced patients with chronic moderate-to-severe pain. Investigators found the guide to be a useful tool to assist conversion of opioid-experienced patients to MSN. Keywords: opioid conversion, rotation, morphine, primary care, safety, equianalgesi