Opioids
Clinical Interpretation of Urine Drug Tests: What Clinicians Need to Know About Urine Drug Screens
Urine drug testing is frequently used in clinical, employment, educational, and legal settings and misinterpretation of test results can result in significant adverse consequences for the individual who is being tested. Advances in drug testing technology combined with a rise in the number of novel misused substances present challenges to clinicians to appropriately interpret urine drug test results. Authors searched PubMed and Google Scholar to identify published literature written in English between 1946 and 2016, using urine drug test, screen, false-positive, false-negative, abuse, and individual drugs of abuse as key words.Future Directions in Pain Management: Integrating Anatomically Selective Delivery Techniques With Novel Molecularly Selective Agents
Treatment for chronic, locoregional pain ranks among the most prevalent unmet medical needs. The failure of systemic analgesic drugs, such as opioids, is often due to their off-target toxicity, development of tolerance, and abuse potential. Interventional pain procedures provide target specificity but lack pharmacologically selective agents with long-term efficacy. Gene therapy vectors are a new tool for the development of molecularly selective pain therapies, which have already been proved to provide durable analgesia in preclinical models.Fibromyalgia and Related Conditions
Fibromyalgia is the currently preferred term for widespread musculoskeletal pain, typically accompanied by other symptoms such as fatigue, memory problems, and sleep and mood disturbances, for which no alternative cause can be identified. Earlier there was some doubt about whether there was an “organic basis” for these related conditions, but today there is irrefutable evidence from brain imaging and other techniques that this condition has strong biological underpinnings, even though psychological, social, and behavioral factors clearly play prominent roles in some patients.Neuropathic Pain: Principles of Diagnosis and Treatment
Neuropathic pain is caused by disease or injury of the nervous system and includes various chronic conditions that, together, affect up to 8% of the population. A substantial body of neuropathic pain research points to several important contributory mechanisms including aberrant ectopic activity in nociceptive nerves, peripheral and central sensitization, impaired inhibitory modulation, and pathological activation of microglia. Clinical evaluation of neuropathic pain requires a thorough history and physical examination to identify characteristic signs and symptoms.Development of Peripheral Opioid Antagonists: New Insights Into Opioid Effects
The recent approval by the US Food and Drug Administration of 2 medications—methylnaltrexone and alvimopan—introduces a new class of therapeutic entities to clinicians. These peripherally acting μ-opioid receptor antagonists selectively reverse opioid actions mediated by receptors outside the central nervous system, while preserving centrally mediated analgesia. Methylnaltrexone, administered subcutaneously, has been approved in the United States, Europe, and Canada. In the United States, it is indicated for the treatment of opioid-induced constipation in patients with advanced illness (eg, cancer, AIDS) who are receiving palliative care, when response to laxative therapy has not been sufficient.
