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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fentanyl induced seizures have been described previously in the literature. Clinical observations has labeled the movements seen in fentanyl anesthesia as seizure activity but electroencephalographic studies have not supported this. A case of seizure-like activity after the administration of fentanyl in a 20-year-old female is reported.
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PMID:Seizure-like activity during fentanyl anesthesia. A case report. 215 4

The effect on the parameters of seizures of opiates, administered in doses used clinically for analgesic effects, was studied in rats with full amygdaloid-kindled seizures. The largest dose of fentanyl studied (100 micrograms/kg) had a pronounced inhibitory effect on kindled seizures: severity of seizures, duration of seizures and duration of afterdischarge were significantly reduced to 36, 40 and 37% of controls, respectively, and the latency of seizures was significantly increased to 168% of untreated animals. The largest dose of pentazocine (16 mg/kg) also significantly inhibited the duration of seizures and duration of afterdischarge. Morphine (1-4 mg/kg) and meperidine (4-16 mg/kg) had a tendency to inhibit the duration of seizure and afterdischarges but did not significantly affect any of the measured parameters of seizures. Fentanyl, meperidine and pentazocine resulted in a lowering, whereas morphine caused a slight elevation, of the threshold for initiation of kindled seizures. The data suggest that fentanyl, in relatively small doses, may cause an inhibition of the intensity of behavioural and electrographic seizures but, paradoxically, an increased sensitivity to induction of seizures in rats with full amygdaloid-kindled seizures.
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PMID:Effect of opiates on the parameters of seizures in rats with full amygdaloid-kindled convulsions. 377 14

Fentanyl reduces the cortical cerebral blood flow and metabolic rate for oxygen in rats, though seizure activity occurs in some animals at high doses. However, the effects of fentanyl on blood flow and metabolism in subcortical structures have not been clearly delineated. The present study examines the effects of intravenous fentanyl (100 or 400 micrograms . kg-1) on local cerebral blood flow (1-CBF) in paralyzed, mechanically ventilated rats. Rats ventilated with 70% N2O in 30% O2 served as controls. Local CBF was measured using 14C-iodoantipyrine and autoradiography. Blood pressure, PaO2, PaCO2, pH, and temperature were comparable in all groups. The EEG showed slow wave activity in most animals given 100 micrograms . kg-1 fentanyl while seizure activity occurred in all animals given 400 micrograms . kg-1 fentanyl. With 100 micrograms . kg-1 fentanyl, CBF tended to be depressed in all cortical and subcortical areas, except the peri-aqueductal gray; and with 400 micrograms . kg-1 fentanyl, 1-CBF tended to be elevated (compared to 100 micrograms . kg-1 fentanyl) in most areas of the brain. The limbic system structures, however, were most affected by 400 micrograms . kg-1 fentanyl with statistically significant increases (compared to the 100 micrograms . kg-1 group) in 1-CBF of 86% and 67% respectively in the amygdala and septal nucleus. These results confirm that moderately high doses of fentanyl which cause slow wave activity on the EEG also depress 1-CBF in rats; moreover, doses of fentanyl that produce seizure activity produce increases in 1-CBF in most cerebral structures with greatest effects on limbic system 1-CBF.
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PMID:Effects of fentanyl on local cerebral blood flow in the rat. 406 Oct 1

There is considerable controversy with respect to the effects of narcotics on the cerebral blood flow (CBF) and the cerebral metabolic rate for oxygen (CMRo2). The present study examined the effects of high doses of intravenous fentanyl (25-400 micrograms/kg) on the CBF and CMRo2 in rats. Cerebral cortical blood flow and metabolism were measured using the 133Xenon modification of the Kety-Schmidt technique. Fentanyl produced a dose-related decrease in both the CBF and the CMRo2. CBF and CMRo2 were maximally depressed by 50 and 35%, respectively, in rats given fentanyl 100 micrograms/kg compared with nitrous oxide-oxygen ventilated controls. The values for CBF and CMRo2 were 168 +/- 15 ml . 100 g-1 . min-1 and 10.3 +/- 0.7 ml . 100 g-1 . min-1, respectively in the nitrous oxide controls compared with 85 +/- 3 ml . 100 g-1 . min-1 and 7.1 +/- 0.1 ml . 100 g-1 . min-1 in animals receiving fentanyl 100 micrograms/kg. Higher doses of fentanyl did not further decrease either CBF or CMRo2 (108 +/- 12 ml . 100 g-1 . min-1 and 7.0 +/- 0.4 ml . 100 g-1 . min-1, respectively for fentanyl 400 micrograms/kg); however, seizures activity was noticed in about 25% of the rats receiving either 200 or 400 micrograms/kg fentanyl. The seizures seemed to be related to the narcotic in that they could be abolished by injections of naloxone. The seizure activity appeared to increase the CMRo2 relative to animals who received the same dose of fentanyl but did not have seizures. The CBF was not affected. The results confirm that narcotics in high enough doses may depress the CBF and CMRo2.
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PMID:The effects of high-dose fentanyl on cerebral circulation and metabolism in rats. 713 18

The traditional view of opioids held that the individual opioid agonists shared the same mechanism of action, differing only in their potency and pharmacokinetic properties. However, recent advances in opioid receptor pharmacology have made this view obsolete. Distinguishing features of the synthetic opioid agonists are related, at least in part, to variation in affinity and intrinsic efficacy at multiple opioid receptors. Respiratory depression is the opioid adverse effect most feared by anaesthesiologists. Specific kappa-receptor agonists produce analgesia with little or no respiratory depression. There are a number of commercially available kappa-receptor partial agonist drugs, the so-called agonist-antagonist or nalorphine-like opioids, which appear to have a limited effect on breathing. Within the series of fentanyl analogues there are differences in behaviour towards particular opioid receptors and there is evidence for subtle differences in respiratory depressant effects. Pethidine (meperidine) causes histamine release and myocardial depression, while the fentanyl analogues do not. Pethidine has atropine-like effects on heart rate, while fentanyl analogues reduce heart rate by a vagomimetic action. Severe bradycardia or even asystole is possible with fentanyl analogues, especially in conjunction with the vagal stimulating effects of laryngoscopy. Fentanyl analogues often produce minor reductions in blood pressure, and occasionally severe hypotension by centrally mediated reduction in systemic vascular resistance. Muscle rigidity and myoclonic movement occurs frequently during induction of anaesthesia with larger doses of opioids. Fentanyl and alfentanil have been reported to produce localised temporal lobe electrical seizure activity in patients with complex partial epilepsy. There are probably fewer biliary effects with agonist-antagonist opioids than the agonist opioids. The mechanism of adverse effects after spinal administration is distinctly different for morphine, which is very water soluble, compared with more lipid-soluble opioids. The systemic absorption of morphine after intrathecal or epidural administration is very slow, resulting in long duration of analgesia and low plasma concentrations, while lipid-soluble opioids are rapidly absorbed into the circulation and redistributed to the brain. The serotonin syndrome may result from coadministration of pethidine, dextromethorphan, pentazocine or tramadol with monoamine oxidase inhibitors (MAOIs) or selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs). There are clinically important interactions between opioids and hypnosedatives, resulting in synergistic effects on sedation, breathing and blood pressure.
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PMID:Adverse effects of opioid agonists and agonist-antagonists in anaesthesia. 974 65

Propofol has been proposed as a sedative agent during awake craniotomies. However, there are reports of propofol suppressing spontaneous epileptiform electrocorticography (ECoG) activity during seizure surgery, while others describe propofol-induced epileptiform activity. The purpose of this study was to determine if propofol interferes with ECoG and direct cortical stimulation during awake craniotomies in children. Children scheduled for awake craniotomies for resection of epileptic foci or tumours were studied. An intravenous bolus of 1-2 mg.kg-1 followed by infusion of 100-200 microgram.kg-1.min-1 of propofol was administered to induce unconsciousness. Fentanyl (0.5 microgram.kg-1) was administered incrementally to provide analgesia. After the cortex was exposed, the propofol infusion was stopped and the patient permitted to awaken. Cortical electrodes were applied. ECoG was recorded continuously on a Grass polygraph. Motor, sensory, language, and memory testing were done throughout the procedure. The cortex was stimulated with a hand-held electrode using sequential increases in voltage to map the relevant speech and motor areas. We studied 12 children (aged 11-15 years) with intractable seizures. The raw ECoG did not reveal any prolonged beta-waves associated with propofol effect. Electroencephalogram spikes due to spontaneous activity or cortical stimulation were easily detected. Cognitive, memory and speech testing was also successful. We conclude that propofol did not interfere with intraoperative ECoG during awake craniotomies. Using this technique, we were able to fully assess motor, sensory, cognitive, speech and memory function and simultaneously avoid routine airway manipulation.
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PMID:The effect of propofol on intraoperative electrocorticography and cortical stimulation during awake craniotomies in children. 1063 6

The aim of this study was to examine effects of i.p. injected Fentanyl (0.005 mg/kg) and Morphine (1 mg/kg) on local cerebral blood flow (ICBF) and tissue pO2 level in frontal-parietal area of the cortex and nucleus accumbens of the rat's brain. Either fentanyl or morphine injection resulted in significant increase of local blood flow in the n.accumbens and its decrease in frontal-parietal area of cortex. Measurement of oxygen partial pressure revealed the opposite (to ICBF) changes: a decrease in n.accumbens and its increase in cortical area of the brain. Analysis of this data and electrical activity recorded from both said structures allow to conclude that they are conditioned by respective changes in functional-metabolic activity induced by intraperitoneal injection either fentanyl or morphine: its suppression in frontal-parietal area of the cortex and development of seizure-like activity in the n.accumbens.
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PMID:[Effect of fentanyl and morphine on local blood flow and tissue oxygen tension in cortical frontal-parietal area and nucleus accumbens in albino rats]. 1285 8

Opioids have been used for analgesia in nearly all civilizations. In paediatrics their use has become widely accepted for combating severe pain, especially postoperative pain and tumour pain. Receptors in the central nervous system are the best known sites of action of opioids, but the existence of peripheral receptors is also probable. The action depends on whether the opioid is more agonist or antagonist and on the peculiarities of physiology in childhood: in the small child a hyperdynamic blood circulation makes resorption faster, and in newborn and premature infants distribution and excretion are influenced by the different composition of the body and the immaturity of liver and kidney. The best known opioid is morphine, and it is the reference substance with which all other opioids are compared. Fentanyl has been used even for the smallest ventilated prematures in recent times, as it is easy to manage and has an early onset of action. Its depressant action on the respiratory centre is an advantage when attempts of spontaneous breathing make mechanical ventilation difficult. Obstinate constipation is the disadvantage of both morphine and fentanyl, and an exacerbation of hyperbilirubinaemia has been seen with fentanyl. Nalbuphine causes a lower degree of respiratory depression. The newer opioids alfentanil and sufentanil have already been used for the relief of paediatric postoperative pain and during mechanical ventilation, but no special advantages of their use are reported. Meperidine has been favoured especially for postoperative pain, although it appears to have no advantages over morphine. Its active metabolite normeperidine may accumulate and cause seizures; meperidine should not be used in prematures or in children with renal dysfunction. There are few publications on the use of piritramide in paediatric pain. Tramadol is widely used for emergencies, as it has the least sedative action; but it has disadvantages in causing nausea and vomiting. Codeine is widely used for its antitussive action. While the necessity of good analgesia for even the smallest infant cannot be overstated, the opioid used must be carefully selected with reference to the age of the child and the pain to be controlled.
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PMID:[Analgesia with opioids in the paediatric patient.]. 1841 33

The prevalence of new psychoactive substances (NPS) on the illicit drug market continues to grow, with new analogs being routinely synthesized. Routes of administration for these compounds are also diversifying, and recent research has shown an increase in the incorporation of NPS into vaping liquids. Among the most commonly encountered NPS are the cathinone and fentanyl analogs. Fentanyl analogs in particular have been implicated in a significant number of deaths, usually in combination with other prescription and illicit drugs. We report the case of a 44-year-old male with a history of polysubstance abuse found deceased at his home address. Items located within the vicinity of the deceased were found to contain furanylfentanyl and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MMMP also known as MTMP, MMTMP, Irgacure 907 and Caccure 907). Both of these compounds were detected in the post-mortem peripheral blood of the deceased: furanylfentanyl at 1.6 ng/mL and MMMP at 6.7 ng/mL. MMMP is an unrestricted, commercially available photo-initiator used in the printing and polymer industry, which structurally can be classed as a highly modified cathinone. Although MMMP has been found previously in drug seizures, this is the first fatality in which MMMP has been detected. A number of other prescription and illicit drugs were also detected in the blood. MMMP was not detected in the post-mortem urine; however three metabolites, beta-hydroxy-MMMP, beta-hydroxy-MMMP-sulfoxide and beta-hydroxy-MMMP-sulfone, were presumptively identified. The significance of MMMP to the cause of death is uncertain as its pharmacological and toxicological profile is unclear.
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PMID:A Fatality Involving Furanylfentanyl and MMMP, with Presumptive Identification of Three MMMP Metabolites in Urine. 3056 82

Fentanyl and its analogues play a major role in the current opioid epidemic. In particular, these highly potent opioids have become a health hazard due to their use as additives in street drugs. Consequently, rapid on-site procedures for the analysis of this class of seized drugs are needed, especially considering the reported backlog of drug samples, which must undergo identification and confirmation tests to validate the presence of an illicit substance. Paper based devices are cheap sampling and analysis vehicles that have been shown capable of allowing rapid identification and confirmation of drugs of abuse. Modifying paper substrates by imprinting nanoparticles enables surface enhanced Raman spectroscopy (SERS) as well as a second analysis from the same substrate, namely paper spray ionization mass spectrometry. While such a procedure has been described for laboratory use, these illicit drug samples are typically collected in the field and this is where testing should be done. We combine paper SERS and paper spray MS on field-portable and commercial off-the-shelf (COTS) devices for the rapid and low-cost identification and confirmation of fentanyl and its analogues, enabling in situ analysis at the point of seizure of suspect samples. The commercial nature of both instruments moves this technology from the academic realm to a setting where the criminal justice system can realistically utilize it. The capabilities of this single-substrate dual-analyzer technique are further examined by sampling a variety of surfaces of forensic interest.
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PMID:Identification and Confirmation of Fentanyls on Paper using Portable Surface Enhanced Raman Spectroscopy and Paper Spray Ionization Mass Spectrometry. 3212 77


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