Opioids remain the most effective analgesics despite their potential adverse effects such as tolerance and addiction. Mechanisms underlying these opiate-mediated processes remain the subject of much debate. Here we describe opioid-induced behaviors of Lmx1b conditional knockout mice (Lmx1bf/f/p), which lack central serotonergic neurons, and we report that opioid analgesia is differentially depe...

BACKGROUND Morphine has been commonly used for postoperative pain control. We measured plasma concentrations of morphine and compared the efficacy and safety of continuous epidural analgesia (CEA) using morphine-bupivacaine with intravenous patient controlled analgesia (IV-PCA) with morphine for 48 hrs after the end of the operation. METHODS Nineteen patients undergoing Mile's operation were ...

BACKGROUND Intrathecal (IT) morphine provides excellent post-operative analgesia, but causes multiple side effects including nausea and vomiting (PONV), pruritus and respiratory depression, particularly at higher doses. The lowest effective dose of spinal morphine in patients undergoing total knee arthroplasty is not known. METHODS We evaluated the analgesic efficacy and side effect profile o...

This was a prospective randomised, controlled, single-blind study done to determine the effect of intrathecal morphine 0.1 mg as compared with intrathecal fentanyl 25 microg in terms of analgesia and duration for postoperative pain relief after Caesarean section. Sixty ASA I or II parturients were randomised into two groups. Group 1 (n=33) received 1.8 ml of 0.5% hyperbaric bupivacaine combined...

BACKGROUND Efficient pain management is one of the most important components of care in the field of emergency medicine. OBJECTIVES This study was conducted to compare intravenous paracetamol and intravenous morphine sulfate for acute pain reduction in patients with limb trauma. PATIENTS AND METHODS In a randomized double-blinded clinical trial, all patients (aged 18 years and older) with a...

The interactions between the cannabinoid and opioid systems for pain modulation are reciprocal. However, the role and the importance of the cannabinoid system in the antinociceptive effects of opioids remain uncertain. We studied these interactions with the goal of highlighting the involvement of the cannabinoid system in morphine-induced analgesia. In both phases of the formalin test, intra pa...

INTRODUCTION Opioid analgesia can be explored with quantitative sensory testing, but most investigations have used models of phasic pain, and such brief stimuli may be limited in the ability to faithfully simulate natural and clinical painful experiences. Therefore, identification of appropriate experimental pain models is critical for our understanding of opioid effects with the potential to i...

BACKGROUND The analgesic potency of opioids is reduced in neuropathic pain. However, the molecular mechanism is not well understood. RESULTS The present study demonstrated that increased methylation of the Mu opioid receptor (MOR) gene proximal promoter (PP) in dorsal root ganglion (DRG) plays a crucial role in the decreased morphine analgesia. Subcutaneous (s.c.), intrathecal (i.t.) and intr...

Thirty-eight ASA I-III patients undergoing lower abdominal operations were randomly allocated to receive either morphine (group M, patient-controlled analgesia bolus = 1 mg of morphine) or tramadol (group T, patient-controlled analgesia bolus = 10 mg of tramadol) for post-operative patient-controlled analgesia (PCA) after receiving morphine intraoperatively. There were no between-group differen...

BACKGROUND AND PURPOSE Pain after total knee arthroplasty (TKA) is usually severe, and epidural analgesia or femoral nerve block has been considered to be an effective pain treatment. Recently, local infiltration analgesia (LIA) has become increasingly popular but the outcome of this method regarding the analgesic effect has not been fully evaluated. We compared local infiltration analgesia and...