piperidines and Fasciculation

Succinylcholine is a popular muscle relaxant and one of its most common side effects is muscle fasciculation. The purpose of this study was to evaluate the efficacy of remifentanil in preventing succinylcholine-induced fasciculation in patients undergoing general anesthesia.. In aprospective, double blind study, 60 ASA I & II patients were randomly assigned into two groups (30 each) to receive either remifentanil 1 microg/kg (Group R), or saline 3 ml (Group S) as a pretreatment agent, one minute before induction of general anesthesia by propofol, fentanyl, and 1.5 mg/kg succinylcholine. The duration and the intensity of fasciculation were assessed using a four-point rating scale. Data were analyzed by Mann-Whitney U-test, Fisher exact test and Student-t-test using SPSS software.. In the remifentanil group the duration (p < 0.001) and the intensity (p < 0.001) of fasciculation were lower compared to the saline group. However the incidence of bradycardia was higher in the remifentanil group in comparison to the group which received normal saline.. Our findings indicate that remifentanil can reduce the duration and the intensity of succinylcholine induced fasciculation. However, it induces greater bradycardia.

Topics: Adult; Anesthesia, General; Anesthetics, Combined; Anesthetics, Intravenous; Bradycardia; Double-Blind Method; Fasciculation; Female; Fentanyl; Humans; Male; Middle Aged; Neuromuscular Depolarizing Agents; Piperidines; Propofol; Prospective Studies; Remifentanil; Severity of Illness Index; Statistics, Nonparametric; Succinylcholine; Young Adult

The present visual and electromyographic study was designed to evaluate muscle fasciculations caused by succinylcholine in adults pretreated with either remifentanil 1.5 microg/kg or saline.. The effect of remifentanil on succinylcholine-induced muscle fasciculations was studied using a double-blind method in 40 adults. After i.v. pretreatment with either remifentanil 1.5 microg/kg (remifentanil group, n = 20) or an equivalent volume of i.v. saline (saline group, n = 20), patients were anaesthetized with a 2.0 mg/kg of i.v. propofol followed by i.v. succinylcholine 1.0 mg/kg. Intensity and duration of muscle fasciculation following i.v. succinylcholine administration were recorded. Electromyography (EMG) was used to quantify the extent of muscle fasciculation following i.v. succinylcholine injection. Myalgia was evaluated 24 hours after induction time. Serum potassium levels were measured five minutes after i.v. succinylcholine administration and creatine kinase (CK) levels 24 hours after induction time.. Compared to saline treated controls, remifentanil decreased the intensity of muscle fasciculations caused by i.v. succinylcholine [fasciculation severity scores (grade 0 to 3) were 2/1/12/5 and 3/13/4/0 (patients numbers) in the saline group and the remifentanil group, respectively, p < 0.001]. The mean (SD) maximum amplitude of muscle action potential (MAP) by EMG was smaller in the remifentanil group [283.0 (74.4) microV] than in the saline group [1480.4 (161.3) microV] (p = 0.003). Postoperative serum CK levels were lower in the remifentanil group (p < 0.001). Postoperative myalgia was not different between the two groups.. Remifentanil 1.5 microg/kg attenuated intensity of muscle fasciculations by succinylcholine.

Topics: Adult; Aged; Blood Pressure; Creatine Kinase; Double-Blind Method; Electromyography; Fasciculation; Female; Humans; Male; Middle Aged; Piperidines; Remifentanil; Succinylcholine

The cholinesterase inhibitors huperzine A, donepezil and rivastigmine were compared for their effects on extracellular acetylcholine concentration and acetylcholinesterase activity in the rat cortex. After i.p. injection, huperzine A (0.25-0.75 micromol/kg), donepezil (2-6 micromol/kg) and rivastigmine (0.75-1.5 micromol/kg) dose-dependently elevated the concentration of acetylcholine. The duration of huperzine A was longest. The time courses of cortical acetylcholinesterase inhibition with middle doses of these agents mirrored the increases of acetylcholine at the same doses. However, acetylcholinesterase inhibition was disproportionately greater after middle dose of rivastigmine than doses of huperzine A and donepezil that increased acetylcholine to a similar extent. Muscle fasciculation appeared only after donepezil with a dose-dependent incidence and intensity. In molar terms, huperzine A was 8- and 2-fold more potent than donepezil and rivastigmine, respectively, in increasing cortical acetylcholine levels, with a longer-lasting effect.

Topics: Acetylcholine; Acetylcholinesterase; Alkaloids; Alzheimer Disease; Animals; Brain Chemistry; Carbamates; Cerebral Cortex; Cholinesterase Inhibitors; Donepezil; Dose-Response Relationship, Drug; Fasciculation; Indans; Male; Neurons; Phenylcarbamates; Piperidines; Rats; Rats, Sprague-Dawley; Rivastigmine; Sesquiterpenes; Up-Regulation

This study was designed to investigate the central and peripheral activity profile of cholinesterase inhibitors in rats. Intravenous injection of cholinesterase inhibitors caused fasciculation, a fine involuntary muscular movement. This peripheral cholinergic sign was tightly correlated with in vitro anti-acetylcholinesterase activity by cholinesterase inhibitors, suggesting that fasciculation is a valid index of peripheral cholinergic activation. Yawning, used as a marker of central cholinergic activation, was also monitored. E2030 (3-(2-(1-(1,3-dioxolan-2-ylmethyl)-4-piperidyl)ethyl)-2H-3,4-dihydro-1,3-benzoxazin-2,4-dione hydrochloride) elicited yawning at more than 4 mg/kg, while fasciculation was significantly intensified only at a dose of 16 mg/kg. Donepezil and tacrine induced both yawning and fasciculation at doses greater than 4 mg/kg, whereas physostigmine induced both behaviors at a dose of 8 mg/kg and above. Finally, ipidacrine elicited yawning at a dose of 16 mg/kg and fasciculation at doses greater than 8 mg/kg. Thus, all putative centrally acting cholinesterase inhibitors elicited yawning. TAK-147 (3-[1-(phenylmethyl)-4-piperidinyl]-1-(2,3,4,5-tetrahydro-1H-benzazepin-8-yl)-1-propanone fumarate) did not significantly elicit yawning at doses under 16 mg/kg, but elicited fasciculation at a dose of more than 4 mg/kg. Distigmine, a peripherally acting cholinesterase inhibitor, evoked fasciculations, but not yawning. When mild to moderate fasciculation was evoked, donepezil and E2030 elicited more than nine yawns over 30 min, while the other cholinesterase inhibitors elicited approximately five yawns at most during this period. These results indicated that E2030 and donepezil exhibited the most marked preferential central cholinergic activity, relative to peripheral activity, among cholinesterase inhibitors tested. Scopolamine, a centrally acting antimuscarinic drug, completely inhibited E2030-induced yawning, while peripherally acting methylscopolamine did not. Haloperidol, a dopamine receptor antagonist, partially blocked E2030-induced yawning, but did not block donepezil-induced yawning. These results suggest that central cholinergic and, in part, dopaminergic mechanisms are involved in E2030-induced yawning.

Topics: Acetylcholinesterase; Animals; Benzazepines; Benzoxazines; Butyrylcholinesterase; Cholinesterase Inhibitors; Donepezil; Fasciculation; Indans; Male; Muscarinic Antagonists; Oxazines; Piperidines; Rats; Rats, Wistar; Tacrine; Yawning