BACKGROUND Ultiva® is commonly administered intravenously for analgesia during general anaesthesia and its main constituent remifentanil is an ultra-short-acting μ-opioid receptor agonist. Ultiva® is not approved for epidural or intrathecal use in clinical practice. Previous studies have reported that Ultiva® provokes opioid-induced hyperalgesia by interacting with spinal dorsal horn neurons. U...

BACKGROUND Thoracotomy induces severe postoperative pain and impairment of pulmonary function, and therefore regional analgesia has been intensively studied in this procedure. Thoracic epidural analgesia is commonly considered the "gold standard" in this setting; however, evaluation of the evidence is needed to assess the comparative benefits of alternative techniques, guide clinical practice a...

We have previously demonstrated that both endomorphin-1 and endomorphin-2 produce their antinociception by the stimulation of mu-opioid receptors. However, the antinociception induced by endomorphin-2 contains an additional component, which is mediated by the release of dynorphin A (1-17) acting on kappa-opioid receptors. These studies were done to determine whether the antinociception induced ...

Opioid agonists such as morphine have been found to exert excitatory and inhibitory receptor-mediated effects at low and high doses, respectively. Ultra-low doses of opioid antagonists (naloxone and naltrexone), which selectively inhibit the excitatory effects, have been reported to augment systemic morphine analgesia and inhibit the development of tolerance/physical dependence. This study inve...

OBJECTIVES Intrathecal morphine is used in the postoperative management of pain after caesarean section (CS), but might not be optimal for intraoperative analgesia. We hypothesized that intrathecal fentanyl could supplement intraoperative analgesia when added to a local anesthetic and morphine without affecting management of postoperative pain. METHODS This prospective, randomized, double-bli...

OBJECTIVES In a companion article, we synthesized current clinical and preclinical data to formulate hypotheses about the etiology of drug administration catheter-tip inflammatory masses. In this article, we communicate our recommendations for the detection, treatment, mitigation, and prevention of such masses. METHODS We reviewed published and unpublished case reports and our own experiences...

BACKGROUND Ziconotide is a new analgesic agent administered intrathecally. It is challenging to use and can induce several and sometimes serious adverse events. A low initial dosage followed by slow titration may reduce serious adverse events. OBJECTIVE To determine whether a low starting dosage of ziconotide, followed by slow titration, decreases the incidence of major adverse events associa...

A lanthionine enkephalin derivative, Tyr-c[D-ValL-Gly-Phe-DAlaL ]-OH (DVL DAL LanEnk), where ValL and AlaL denote the lanthionine amino acid ends linked via a monosulfide bridge to form the lanthionine structure, was synthesized. It was found to possess selectivity for and potency at the versus opioid receptor as defined by binding studies and by its respective activity on the mouse vas deferen...

The generation of potent opioid analgesics that lack the side effects of traditional opioids may be possible by targeting truncated splice variants of the μ-opioid receptor. μ-Opioids act through GPCRs that are generated from the Oprm1 gene, which undergoes extensive alternative splicing. The most abundant set of Oprm1 variants encode classical full-length 7 transmembrane domain (7TM) μ-opioid ...