The analgesia produced by combinations of low-dose naloxone with pentazocine or morphine was studied in 105 patients with moderately severe postoperative pain after standardized surgery for removal of impacted third molars. Pain intensity was quantified using a visual-analogue scale. To eliminate the release of endogenous opioids produced by the placebo component of open drug administration, al...

Studies comparing morphine tolerance in males and females are rare, and all studies to date have utilized the rat. To generalize from findings with rats morphine tolerance was investigated in male and female mice using the tail-withdrawal test. Three and 7 days of systemic morphine injections produced significant but unequal rightward shifts in the morphine dose-response curve such that females...

BACKGROUND I.V. morphine titration (MT) allows adjustment of the dose needed for pain relief in the post-anaesthesia care unit (PACU). However, MT has limitations such as a delay to achieve pain relief. We thus assessed the effect of a fixed intraoperative loading dose of morphine administered before titration. METHODS One hundred patients who were undergoing major orthopaedic surgery were in...

BACKGROUND Peripheral tissue injury causes a migration of opioid peptide-containing immune cells to the inflamed site. The subsequent release and action of these peptides on opioid receptors localized on peripheral sensory nerve terminals causes endogenous analgesia. The spinal application of opioid drugs blocks the transmission of nociceptive information from peripheral injury. This study inve...

Desglycinamide(9)-lysine vasopressin facilitates development of resistance to the analgesic action of morphine in mice if morphine is administered before the peptide. Desglycinamide(9)-lysine vasopressin is not a morphine antagonist, and does not appear to cause either hyperalgesia or alteration of the response to the technique used for evaluating analgesia.

BACKGROUND Previous studies have demonstrated that the addition of intrathecal fentanyl to a spinal anesthetic for cesarean delivery improves intraoperative analgesia. However, intrathecal fentanyl may induce acute tolerance to opioids. The objective of this study was to investigate whether the addition of intrathecal fentanyl to spinal anesthesia with intrathecal morphine increases postoperati...

UNLABELLED In this prospective, randomized, and double-blinded clinical trial, we evaluated the efficacy of preincisional administration of epidural ketamine with morphine compared with epidural morphine alone for postoperative pain relief after major upper-abdominal surgery. We studied 50 ASA I and II patients undergoing major upper-abdominal procedures. These patients were randomly allocated ...

BACKGROUND Perioperative thoracic epidural analgesia reduces stress response and pain scores and may improve outcome after cardiac surgery. This prospective, randomized trial was designed to compare the effectiveness of patient-controlled thoracic epidural analgesia with patient-controlled analgesia with intravenous morphine on postoperative hospital length of stay and patients' perception of t...

The analgesic effects of the rat in response to electroacupuncture (EA) or low-dose morphine (3 mg/kg) show marked individual variations. In the midbrain periaqueductal gray (PAG) of the rat, the content of the neuropeptide cholecystokinin octapeptide (CCK-8) was found to be significantly higher in the low responder (LR) rats as compared to that in the high responders (HR). Since PAG has been s...

BACKGROUND The PROSPECT (Procedure-Specific Postoperative Pain Management) Group recommended a single injection femoral nerve block in 2008 as a guideline for analgesia after total knee arthroplasty. Other authors have recommended the addition of sciatic and obturator nerve blocks. The lateral femoral cutaneous nerve is also involved in pain syndrome following total knee arthroplasty. We hypoth...