Pain
-
Some expert guidelines recommend time-scheduled opioid dosing over pain-contingent dosing for patients receiving chronic opioid therapy (COT). The premise is that time-scheduled dosing results in more stable opioid blood levels and better pain relief, fewer adverse effects, less reinforcement of pain behaviors, and lower addiction risk. We report results of a survey of 1781 patients receiving COT for chronic noncancer pain, in which 967 reported time-scheduled opioid dosing only and 325 reported pain-contingent opioid dosing only. ⋯ Controlled comparative effectiveness research is needed to assess benefits and risks of time-scheduled opioid dosing relative to pain-contingent opioid dosing among COT patients in ambulatory care. Patients with time-scheduled dosing received higher opioid dosage than patients with pain-contingent dosing. Time-scheduled dosing was associated with greater opioid control concerns than pain-contingent dosing.
-
It has been proposed that goal pursuit plays a role in the development of chronic pain disorders. On the basis of (affective) motivational theories, it was hypothesized that both long-term achievement goals and short-term hedonic goals would be related to increased levels of pain and disability, particularly in patients with high negative affect. Participants with musculoskeletal pain complaints (N=299) completed a battery of questionnaires including a novel goal pursuit questionnaire (GPQ) measuring the extent to which participants preferred hedonic goals (mood-management or pain-avoidance goals) over achievement goals in various situations. ⋯ These findings provide support for the validity of an affective-motivational approach to chronic pain, suggesting that the experience of pain and the interference of pain on daily life activities depends on goal pursuit and negative affect. Interventions aimed at improving disability in chronic pain should address both patient's goal pursuit and negative affect. An affective-motivational approach to chronic pain indicates that achievement and pain-avoidance goals are associated with pain severity and disability, particularly in patients with high negative affect.
-
Chronic pain is a common reason for medical visits, but prevalence estimates vary between studies and have rarely included drug treatment data. This study aimed to examine characteristics of chronic pain and its relation to demographic and health factors, and factors associated with treatment of pain with opioid analgesics. A chronic pain module was added to the 2007 Kansas Behavioral Risk Factor Surveillance System (response rate = 61%). ⋯ S. A. Overall, 45.7% of people who take prescription drugs for chronic pain reported taking opioid analgesics.
-
Opioid receptors are major actors in pain control and are broadly distributed throughout the nervous system. A major challenge in pain research is the identification of key opioid receptor populations within nociceptive pathways, which control physiological and pathological pain. In particular, the respective contribution of peripheral vs. central receptors remains unclear, and it has not been addressed by genetic approaches. ⋯ Delta receptors in these neurons tonically inhibit mechanical hypersensitivity in both inflammatory and neuropathic pain, and they are essential to mediate delta opioid analgesia under conditions of persistent pain. This delta receptor population represents a feasible therapeutic target to alleviate chronic pain while avoiding adverse central effects. The conditional knockout of delta-opioid receptor in primary afferent Na(V)1.8 neurons augmented mechanical allodynia in persistent pain models and abolished delta opioid analgesia in these models.
-
The development of new strategies for the treatment of acute pain requires the identification of novel nonopioid receptor targets. This study explored whether δ-subunit-containing GABA(A)Rs (δGABA(A)Rs) in neurons of the spinal cord dorsal horn generate a tonic inhibitory conductance in vitro and whether δGABA(A)R activity regulates acute nociception. Whole-cell recordings revealed that δGABA(A)Rs generate a tonic inhibitory conductance in cultured spinal neurons and lamina II neurons in spinal cord slices. ⋯ Surprisingly, THIP reduced the enhanced phase 2 response in Gabrd(-/-) mice. Together, these results suggest that δGABA(A)Rs in spinal neurons play a major physiological and pharmacological role in the regulation of acute nociception and central sensitization. Spinal δ-subunit-containing GABA(A) receptors were identified with electrophysiological methods and behavioral models as novel targets for the treatment of acute pain.