European journal of pain : EJP
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Chronic neuropathic pain arising from peripheral nerve damage is a severe clinical issue where there is a major unmet medical need. We previously demonstrated that both neurotensin (NT) receptor subtypes 1 (NTS1) and 2 (NTS2) are involved in mediating the naloxone-insensitive antinociceptive effects of neurotensin in different analgesic tests including hotplate, tail-flick, and tonic pain. However, the role of these receptors in neuropathic pain management has been poorly investigated. ⋯ Intrathecal administration of the NTS1-selective agonist, PD149163 (30-90 μg/kg) also produced potent anti-allodynic and anti-hyperalgesic effects in nerve-injured rats. Likewise, heat hyperalgesia and tactile allodynia produced by CCI of the sciatic nerve were fully reversed by the NTS1 agonist, NT69L (5-25 μg/kg). Altogether, these results support the idea that the NTS1 receptor subtype is involved in pain modulation, and the potential use of NTS1 agonists for the treatment of painful neuropathies.
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We investigated the prevalence and intensity of pain, factors associated with having pain, and analgesic medications employed in a population consisting predominantly of Black African and female human immunodeficiency virus (HIV)-positive individuals attending outpatient clinics in a rural (n = 125; 79% female; 100% Black African) and a metropolitan (n = 396; 75% female; 94% Black African) area of South Africa. Pain intensity, interference and treatment were assessed using the Wisconsin Brief Pain Questionnaire. Seventy-two percent of rural participants and 56% of metropolitan participants had pain at the time of the interview, and this pain was moderate to severe in intensity in 60% of rural participants and 59% of metropolitan participants. ⋯ Pharmacological management of pain was poor, with 29% of rural participants and 55% of metropolitan participants with pain not receiving any treatment. Of those receiving treatment, no participants were receiving strong opioids, and only 3% of metropolitan participants were receiving a weak opioid. Thus, HIV-related pain is common and is poorly treated in both the rural and metropolitan setting in South Africa.
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Randomized Controlled Trial
What do plasma beta-endorphin levels reveal about endogenous opioid analgesic function?
Plasma levels of beta-endorphin (BE), an endogenous opioid analgesic, are often reported as they relate to acute and chronic pain outcomes. However, little is known about what resting plasma BE levels might reveal about functioning of the endogenous opioid antinociceptive system. This study directly examined associations between resting plasma BE and subsequent endogenous opioid analgesic responses to acute pain in 39 healthy controls and 37 individuals with chronic low back pain (LBP). ⋯ For the ISC task, these links were significantly more prominent in LBP participants (BE × Participant Type Interactions, p's < 0.05). Results suggest that elevated resting plasma BE may be a potential biomarker for reduced endogenous opioid analgesic capacity, particularly among individuals with chronic pain. Potential clinical implications are discussed.
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Randomized Controlled Trial
Coping when pain is a potential threat: the efficacy of acceptance versus cognitive distraction.
This experiment investigated the impact of brief training in acceptance versus distraction-based pain management on experimental pain tolerance in conditions of lower and higher potential threats. One hundred fifty-one pain-free Chinese adults (93 women, 58 men) randomly assigned to acceptance, distraction or pain education control conditions engaged in a cold pressor test (CPT) after reading validated orienting information designed to prime either the safety of the CPT (lower threat) or symptoms and damaging effects of exposure to extreme cold (higher threat). ⋯ Supplementary analyses identified catastrophizing as a partial mediator of training group differences in pain tolerance. In summary, findings suggested acceptance-based coping is superior to distraction as a means of managing experimental pain, particularly when pain sensations are viewed as comparatively low in potential threat.