Pain
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Randomized Controlled Trial Comparative Study Clinical Trial
Analgesic efficacy and safety of tramadol enantiomers in comparison with the racemate: a randomised, double-blind study with gynaecological patients using intravenous patient-controlled analgesia.
The opioid analgesic tramadol is a racemate and consists of 50% (+)- and 50% (-)-enantiomer. This study investigated analgesic efficacy and safety of both enantiomers after intravenous (i.v.) injection in comparison with the racemate. Ninety-eight patients recovering from major gynaecological surgery under opioid-free halothane anaesthesia were treated in a randomised, double-blind study with (+)-tramadol, (-)-tramadol or the racemate. ⋯ Assessment of laboratory screening, adverse events, vital signs and blood gas monitoring showed no serious drug-related events. Nausea and vomiting were the most frequently reported non-serious side effects and were most often seen with (+)-tramadol. Taking into account both efficacy and safety aspects, the racemate seems to be superior to either enantiomer alone.
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Clinical Trial
A pharmacokinetic approach to resolving spinal and systemic contributions to epidural alfentanil analgesia and side-effects.
A pilot study was conducted in 7 normal volunteers to demonstrate the feasibility of employing pharmacokinetic tailoring to achieve matching plasma opioid concentration-time curves after epidural (e.p.) and intravenous (i.v.) alfentanil administration. Each subject participated in 1 pretest and 2 test sessions. Our pain model was cutaneous electrical stimulation of the finger and toe, adjusted to produce a baseline pain report of 5 (strong pain on a 0-5 scale). ⋯ Onset of pain relief was rapid, and duration was approximately 1.5 h with e.p. and 1 h with i.v. alfentanil. There were no differences in pupil size, ETCO2, or subjective side effects between e.p. versus i.v. administration. We conclude that systemic redistribution from the epidural space appears to account for most, but not all, of the analgesia.
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Supraspinally mediated antinociception has been clearly established for agonists acting via both micro- and delta-opioid receptors. The present experiments were undertaken to further characterize the role of supraspinal opioid delta receptors in the mediation of antinociception in rats and to examine the possible role of putative delta1- and delta2-opioid receptors in the antinociceptive effect. Cannulae directed at the right lateral ventricle, the periaqueductal gray (PAG), or the medullary reticular formation (MRF) were implanted in adult male, Sprague-Dawley rats for the microinjection of [D-Ala2,Glu4]deltorphin (delta2 agonist), [D-Pen2,D-Pen5]enkephalin (DPDPE, delta1 agonist), [D-Ser2,Leu5,Thr6]enkephalin (DSLET, mixed delta/micro agonist) or morphine (reference micro-opioid). ⋯ Morphine anticociception was not antagonized by either DALCE or Cys-DELT. These data demonstrate that supraspinal delta-opioid receptors can be activated to elicit antinociception in the rat and that opioid delta2 receptors predominate in this effect. Further, these effects may occur predominately via inhibition of supraspinally organized behavior without activation of descending systems such as those mediating the TF response in the rat.
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Randomized Controlled Trial Comparative Study Clinical Trial
Intrathecal steroids to reduce pain after lumbar disc surgery: a double-blind, placebo-controlled prospective study.
This double-blind, placebo-controlled prospective study investigated whether corticosteroids (beta-methasone) influence residual radicular pain after lumbar disc surgery. The study population consisted of 26 patients undergoing surgery for a herniated lumbar disc at our University Neurosurgical Department. Thirteen patients received beta-methasone intrathecally prior to wound closure, and 13 patients received normal saline. ⋯ At follow-up after 6 months, residual radicular pain was rated equally by both groups (4 mm in the treatment vs. 5 mm in the placebo group, P > 0.5). Intrathecal application of steroids provides short-lasting, significant pain reduction after lumbar disc surgery. Benefits of intrathecal steroids are probably outweighed by the risks associated with violation of the dural barrier.
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Clinical Trial Controlled Clinical Trial
Effects of regional intravenous guanethidine in patients with neuralgia in the hand; a follow-up study over a decade.
A study on the effect of regional intravenous (i.v.) guanethidine blockade (RGB) was done over a 10 years period in patients with post-traumatic neuralgia. Seven patients, investigated with quantitative sensory testing (QST) before and after RGB between 1979 and 1982, were reinvestigated in the period 1990-1992. In addition to the RGB, 6 patients were subjected to a placebo procedure with tourniquet inflation and i.v. injection of saline at follow-up. ⋯ RGB, whereas others consistently had no such effect. None obtained long-lasting pain relief from placebo. This supports the notion that different pathophysiological mechanisms are involved in post-traumatic neuralgia.