The possible characteristics of spinal interaction between sildenafil (phosphodiesterase 5 inhibitor) and morphine on formalin-induced nociception in rats was examined. Then the role of the opioid receptor in the effect of sildenafil was further investigated. Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. For induction of pain, 50 microL of 5% formalin solution ...

Agonists acting at alpha2 adrenergic and opioid receptors have analgesic properties and act synergistically when co-administered in the spinal cord; this synergy may also contribute to the potency and efficacy of spinally administered morphine. The lack of subtype-selective pharmacological agents has previously impeded the definition of the adrenergic receptor subtype(s) mediating these effects...

The endogenous opioid dynorphin A-(1-17) (Dyn A) has been implicated as a mediator of tissue damage after traumatic spinal cord injury (TSCI) and causes hindlimb paralysis when administered intrathecally. Motor impairment following intrathecal Dyn A is attenuated by antagonists of excitatory amino acids (EAAs); whether opioid receptors mediate such injury has been questioned. TSCI causes variou...

DALDA (H-Tyr-D-Arg-Phe-Lys-NH2) and [Dmt ]DALDA (H-DmtD-Arg-Phe-Lys-NH2) (Dmt 5 29,69-dimethyltyrosine) are potent and highly selective m-opioid agonists (Ki d/Ki m . 10,000 and Ki k/Ki m . 100). Both peptides carry a 31 charge at physiological pH. Their antinociceptive and respiratory effects were compared with morphine (MOR) after intrathecal administration in rats. Both DALDA and [Dmt]DALDA ...

To enhance analgesia, the combinatorial use of analgesic drugs with proven efficacies is a widely-used strategy to reduce adverse side effects. The present study characterizes the antinociceptive interaction of intrathecal morphine co-administered with different NSAIDs using isobolographic analysis.Antinoceptive activity was evaluated using a model for acute visceral pain, the writhing test of ...

Background: Implantable pumps for intrathecal opioid therapy in the last decades emerged as one of the most effective treatment for chronic non-malignant pain (CNMP) in selected patients. This study analyses reliability of intrathecal infusion morphine therapy for chronic and refractory pain not related to malignancy using an implantable constant flow pump. Methods: we studied eleven patients (...

UNLABELLED Methadone is a synthetic opioid analgesic that is used as an alternate to morphine and hydromorphone for patients with severe pain. It is increasingly being used in opioid rotation schedules. Methadone has an asymmetric carbon atom resulting in 2 enantiomeric forms, the d and l isomers. The racemic mixture (dl-methadone) is the form commonly used clinically. Recent studies have revea...

BACKGROUND Spinal analgesia, mediated by opioid receptors, requires only a fraction of the opioid dose that is needed systemically. By infusing a small amount of opioid into the cerebrospinal fluid in close proximity to the receptor sites in the spinal cord, profound analgesia may be achieved while sparing some of the side effects due to systemic opioids. Intraspinal drug delivery (IDD) has bee...

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INTRODUCTION Cancer pain is one of the most frequently encountered pain syndromes. With the application of the World Health Organization analgesic ladder, adequate analgesia is achieved in 75% to 90% of patients. The remaining patients suffer from intractable pain requiring intrathecal analgesia. The aim of this study was to retrospectively analyse the pain intensity before and after intratheca...