Tolerance to the analgesic effect of an opioid is a pharmacological phenomenon that occurs after its prolonged administration. Activation of the NMDA receptor (NMDAR) has been implicated in the cellular mechanisms of opioid tolerance. However, activation of NMDARs can lead to neurotoxicity under many circumstances. Here we demonstrate that spinal neuronal apoptosis was induced in rats made tole...

Ten brains from leukaemic patients given intrathecal methotrexate and 10 from leukaemic patients without intrathecal therapy have been examined. Three of the methodtrexate treated patients appear to have died from their therapy. The histological changes consisted of destruction of oligodendrocytes, sometimes complete over large areas, and sometimes relatively slight. All the patients who surviv...

The role of the endogenous opioid system in modulation of urinary bladder activity by spinal nerve (SN) stimulation was studied in anesthetized female rats, using the rat model of isovolumetric bladder contraction. SN stimulation at a fixed frequency of 10 Hz attenuated bladder contraction frequency; the magnitude of the inhibition was directly proportional to the current intensity. Neither the...

Painful diabetic neuropathy is poorly controlled by analgesics and requires high doses of opioids, triggering side effects and reducing patient quality of life. This study investigated whether enhanced Rab7-mediated lysosomal targeting of peripheral sensory neuron μ-opioid receptors (MORs) is responsible for diminished opioid responsiveness in rats with streptozotocin-induced diabetes. In diabe...

BACKGROUND The use of opioids for noncancer pain is widespread, and more than 16,000 die of opioid-related causes in the United States annually. The patients at greatest risk of death are those receiving high doses of opioids. Whether sex influences the risk of dose escalation or opioid-related mortality is unknown. METHODS AND FINDINGS We conducted a cohort study using healthcare records of ...

BACKGROUND Increases in prescriptions of opioid medications for chronic pain have been accompanied by increases in opioid overdoses, abuse, and other harms and uncertainty about long-term effectiveness. PURPOSE To evaluate evidence on the effectiveness and harms of long-term (>3 months) opioid therapy for chronic pain in adults. DATA SOURCES MEDLINE, the Cochrane Central Register of Control...

When isoniazid is used for the chemotherapy of tuberculous meningitis the need for intrathecal therapy is controversial. A Scottish Joint Committee (1957) concluded from a comparative trial, including both adults and children, that intrathecal streptomycin is not now an essential part of the treatment. But, in fact, all the patients reported did receive intrathecal streptomycin for at least one...

Given the increase of opioid dependence and opioid-related morbidity and mortality, improving treatment options for individuals with opioid dependence warrants increased attention. This article provides a concise review of work in this area. Remission from opioid dependence can be very difficult to sustain, particularly in the absence of opioid replacement or opioid antagonist therapy. For thos...

BACKGROUND A subset of the population receiving opioids for the treatment of acute and chronic clinical pain develops a paradoxical increase in pain sensitivity known as opioid-induced hyperalgesia. Given that opioid analgesics are one of few treatments available against clinical pain, it is critical to determine the key molecular mechanisms that drive opioid-induced hyperalgesia in order to re...