To the Editor:—In his editorial, Eisenach highlighted an interesting paradox; while attempting to produce profound analgesia with high doses of potent opioids, it is possible to produce a “preemptive hyperalgesic” effect. In the two human studies referenced, high doses of systemic remifentanil and fentanyl produced acute hyperalgesia. In a previous human study, we found evidence that intratheca...

This pilot study investigates the effect fentanyl has on heart rate variability (HRV) in the operating theatre. Many studies on the effect of anaesthetic agents on HRV include fentanyl in the anaesthetic mix but few studies look at the effect of fentanyl in isolation. HRV uses changes in heart rate to indirectly observe changes in the activity of the autonomic nervous system and in particular, ...

In May 2013, the Rhode Island State Health Laboratories noticed an unusual pattern of toxicology results among 10 overdose deaths of suspected illicit drug users that had occurred during March 7-April 11, 2013. An enzyme-linked immunosorbent assay (ELISA) for fentanyl in blood was positive for fentanyl in all 10 cases, but confirmatory gas chromatography/mass spectrometry (GC/MS) did not detect...

The performance of recently introduced Surgical Stress Index (SSI), based on heart rate and photoplethysmography, was estimated during sevoflurane-fentanyl and isoflurane-fentanyl anesthesia during surgical procedures. Forty ASA I-III patients were enrolled. Anesthesia was induced with fentanyl 2 mug kg(-1) and thiopentone 3-5 mg kg(-1). Tracheal intubation was performed 5 minutes after fentany...

BACKGROUND We previously proposed dosing weights for fentanyl, termed 'pharmacokinetic mass', that span the total body weight (TBW) range from 40 to 210 kg. In this study, we examined the relationships among fentanyl doses needed to achieve postoperative analgesia, corresponding plasma fentanyl concentrations, and pharmacokinetic mass in lean and obese patients undergoing abdominal surgery. M...

BACKGROUND The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration (EC50) in a 20-ml volume for epidural analgesia in the first stage of labor. The aim of this study was to determine the relative local anesthetic sparing efficacies of intravenous and epidural fentanyl by comparison of their effects on the MLAC of bupivacaine. MET...

BACKGROUND The modifying effects of fentanyl on protective airway reflexes have not been characterized in children. The aim of this study was to assess the impact of increasing doses of fentanyl on laryngeal reflex responses in children anesthetized with sevoflurane. The authors hypothesized that the incidence of laryngospasm evoked by laryngeal stimulation is reduced with increasing doses of f...

OBJECTIVES To compare patients' preference for transdermal fentanyl or sustained release oral morphine, their level of pain control, and their quality of life after treatment. DESIGN Randomised, multicentre, international, open label, crossover trial. SETTING 35 centres in Belgium, Canada, Denmark, Finland, the United Kingdom, the Netherlands, and South Africa. PARTICIPANTS 256 patients (...

Fentanyl is a basic amine shown to have extensive first-pass pulmonary uptake. To evaluate the role of the pulmonary endothelium in this uptake process, the simultaneous pharmacokinetics of [3H]fentanyl and two marker drugs, blue dextran, and [14C]antipyrine, were evaluated in a flow-through system of pulmonary endothelial cells. Fentanyl equilibrium kinetics were determined in a static culture...

Fentanyl is a potent mu opioid receptor agonist that was discovered to identify an improved human health analgesic over morphine, an opioid frequently associated with histamine-release, bradycardia, hyper- or hypotension, and prolonged postoperative respiratory depression. Historically, the pharmacological features of fentanyl have been described primarily through the study of the human approve...