Jette N, Patten S, Williams J, Becker W, Wiebe S.

Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.

Background.- Migraine is common, with an estimated lifetime prevalence of 7-17%. Population-based studies have reported an association between various psychiatric conditions and migraine. This is a population-based study exploring the association between migraine and psychiatric disorders in a large cohort and assessing various health-related outcomes. Objective.- (1) Determine the prevalence of various psychiatric conditions in association with migraine; (2) describe the patterns of association of these comorbidities with a variety of health-related outcomes. Methods.- Data from the 2002 Canadian Community Health Survey were used. This is a national health survey which included administration of the World Mental Health Composite International Diagnostic Interview to a sample of 36,984 subjects. Health-related outcomes included 2-week disability, restriction of activities, quality-of-life, and mental health care utilization. Results.- The prevalence of physician-diagnosed migraine (n = 36,984) was 15.2% for females and 6.1% for males. Migraine was most common in those between ages 25 and 44 years and in those of lower income. Migraine was associated with major depressive disorder, bipolar disorder, panic disorder, and social phobia, all occurring more than twice as often in those with migraines compared with those without. Migraine was not associated with drug, alcohol, or substance dependence. The higher prevalence of psychiatric disorders in migraineurs was not related to sociodemographic variables. Psychiatric disorders were less common in those over 65 years, in those who were in a relationship, and in those of higher income whether migraine was present or not. Health-related outcomes were worst in those with both migraines and a psychiatric disorder and intermediate in those with either condition alone. Conclusion.- Migraine is associated with major depressive disorder, bipolar disorder, panic disorder, and social phobia. Migraine in association with various mental health disorders results in poorer health-related outcomes compared with migraine or a psychiatric condition alone. Understanding the psychiatric correlates of migraine is important in order to adequately manage this patient population and to guide public health policies regarding health services utilization and health-care costs.

PMID: 18070059 [PubMed – as supplied by publisher]

Hamann S, Sloan P.

Department of Anesthesiology, University of Kentucky Medical Center, Lexington, USA.

BACKGROUND: Years’ worth of observations suggest that morphine has both inhibitory and excitatory actions, and that selective blockade of excitatory effects by low doses of opioid antagonists (e.g., naltrexone) may paradoxically enhance morphine analgesia. The purpose of this pilot study was to evaluate and compare the analgesic efficacy and safety of two different low doses of oral naltrexone given in addition to chronic intrathecal morphine infusions in patients with chronic nonmalignant pain (CNMP). METHODS: After institutional review board approval, 15 patients with CNMP receiving continuous intrathecal morphine were admitted into a prospective, randomized, double-blind, placebo-controlled, seven-day pilot study. Patients were randomized into three treatment groups based on oral naltrexone dose: 100 microg (Group A, n = 3), 10 microg (Group B, n = 7), or placebo (Group C, n = 5). All patients continued with their constant intrathecal morphine infusion, and in addition they received one capsule of study medication every 12 hours for seven days. Other analgesics or coanalgesics were kept at a constant dose level throughout the study. Patients rated pain scores (visual analogue score [VAS]; 0 = no pain, 10 = worst pain imaginable) and side effects three times daily throughout the study period. Efficacy measures included pain intensity difference (PID) scores, constructed so that positive scores indicate a reduction in pain intensity and negative scores indicate a worsening of pain. RESULTS: Fifteen patients (six male, nine female) with a mean (SD) age of 55 (10) years and weight of 81 (21) kg completed the study. The mean (SD) baseline VAS pain intensity rating was similar in all three groups (6.8 [1.5]). Baseline pain VAS score minus the lowest daily pain VAS score yielded the peak PID score. The peak PID score from Day 1 was statistically (p < 0.05) highest (median PID score: 5.9) in Group A compared with Group C. There was a trend in PID scores across Days 2 through 7, with median PID scores higher (i.e., greater pain relief p = 0.07) in Group A. In the daily global pain assessments, the pain scores across Days 2 through 7 approached significance (least pain) in Group A compared to Group C (p = 0.07) or B (p = 0.08). Side effects were common (93 percent of patients), minor (headache, nausea, sedation, dry mouth), and similar across treatment groups. No serious adverse events were observed, and no evidence of opioid withdrawal was seen. CONCLUSIONS: 1) Patients with chronic pain who received oral naltrexone 100 microg BID in addition to their chronic intrathecal morphine infusions demonstrated the greatest improvement (p = 0.07) in their daily pain scores. Because of the small sample size, the results did not reach traditional levels of significance. 2) Side effects were common, minor, and similar across treatment groups. 3) No serious adverse events were recorded. 4) No evidence of opioid antagonist toxicity or opioid withdrawal was observed.

Publication Types:

• Research Support, Non-U.S. Gov’t

PMID: 18027539 [PubMed – in process]

Machelska H, Stein C.

Klinik für Anaesthesiologie und operative Intensivmedizin, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200, Berlin, Germany. halina.machelska@charite.de

In peripheral inflamed tissue interactions between leukocyte-derived opioid peptides and opioid receptors on sensory neurons lead to potent, clinically relevant inhibition of pain. Opioid receptors are present on peripheral terminals of sensory neurons and are upregulated in inflammation. Their endogenous ligands, opioid peptides, are synthesized in circulating immune cells, which migrate to injured tissues directed by chemokines and adhesion molecules. Under stressful stimuli or in response to releasing agents (e.g., corticotropin-releasing factor, cytokines, catecholamines) leukocytes can secrete opioids. These peptides activate peripheral opioid receptors and produce analgesia by inhibiting the excitability of sensory nerves and/or the release of excitatory neuropeptides. These effects occur without central opioid side effects such as depression of breathing, clouding of consciousness, or addiction. Future research should elucidate the selective targeting of opioid peptide-containing immune cells to sites of painful tissue injury and the augmentation of opioid peptide and receptor synthesis.

Publication Types:

• Research Support, Non-U.S. Gov’t
• Review

PMID: 18040794 [PubMed – in process]