Tramadol is one of the most widely used centrally acting analgesics worldwide. Because of its multimodal analgesic mechanism (opioid plus nonopioid), the adverse effects profile of tramadol, similar to its analgesic profile, can be atypical compared with single-mechanism opioid analgesics. The comparison is often favorable (e.g., less respiratory depression or abuse), but it is sometimes cited ...

The metabolism of cis-tramadol has been studied in human liver microsomes and in cDNA-expressed human cytochrome P-450 (CYP) isoforms. Human liver microsomes catalyzed the NADPH-dependent metabolism of tramadol to the two primary tramadol metabolites, namely, O-desmethyl-tramadol (metabolite M1) and N-desmethyl-tramadol (metabolite M2). In addition, tramadol was also metabolized to two minor se...

Tramadol, a centrally acting analgesic, consists of two enantiomers, both of which contribute to analgesic activity via different mechanisms. (+) Tramadol and the metabolite (+) -Odesmethyl-tramadol (M1) are agonists of the mu opioid receptor. (+) Tramadol also stimulates presinaptic release of serotonin and inhibits serotonin reuptake weheres (-) tramadol inhibits norepinephrine reuptake. Thus...

Tramadol is a centrally acting opioid analgesic which is mainly used for the treatment of moderate to severe pain [2]. Its efficiency and potency ranges between weak opioids and morphine [3]. Tramadol is rapidly absorbed orally; Tramadol has extensive tissue distribution. The bioavailability of tramadol is 70 % its bioavailability is more than that of morphine (1565%) when tramadol is used in m...

OBJECTIVES The aim of this study was to investigate whether tramadol had a dose-dependent blocking effect on nerve conduction when administered perineurally to the sural nerve of healthy volunteers. METHODS Twenty-four informed healthy subjects were randomized into four equal groups [Saline (placebo), 0.5% tramadol, 1% tramadol and 1.5% tramadol]. The study was designed to be double-blinded. ...

BACKGROUND Tramadol is a centrally acting analgesic, whose mechanism of action involves opioid-receptor activation. Previously, we have shown that tramadol and its enantiomers had a negative inotropic effect on the papillary muscle in which the (+)-enantiomer is more potent than (-)- and (±)-tramadol. OBJECTIVE In this study, we investigated the effects of tramadol and its enantiomers on L-ty...

Background: Seizure is one of the possible adverse effects of tramadol hydrochloride, a synthetic, centrallyacting analgesic, prescribed for the treatment of moderate to severe pain. In this study, we describe 106 patients with tramadol induced seizures. Methods: The patients, who were referred to Nemazee Hospital, Shiraz, Iran, from March 2006 to March 2008, were examined in this cross-section...

UNLABELLED The analgesic tramadol inhibits the neuronal reuptake of norepinephrine and 5-hydroxytryptamine, facilitates 5-hydroxytryptamine release, and activates mu-opioid receptors. Each of these actions is likely to influence thermoregulatory control. We therefore tested the hypothesis that tramadol inhibits thermoregulatory control. Eight volunteers were evaluated on four study days, on whi...

Tramadol is an atypical centrally acting analgesic agent with relatively weak opioid receptor affinity in comparison with its antinociceptive efficacy. Evidence suggests that block of monoamine uptake may contribute to its analgesic actions. Therefore, we have examined the actions of (+/-)-tramadol, (+)-tramadol, (-)-tramadol and O-desmethyltramadol (M1 metabolite) on electrically evoked 5-HT e...

BACKGROUNDS Remifentanil has been reported to cause post-anesthetic shivering (PAS). Higher doses of remifentanil reportedly induce more intense PAS. Tramadol, a synthetic opioid that acts at multiple sites, is considered to be an effective treatment for PAS, but the evidence for its therapeutic benefit after remifentanil anesthesia is limited. We investigated the effect of tramadol on the inci...