Alfred A. Smith, Meta Karmin, Joann Gavitt,
Alfentanil-midazolam analgesic interactions were studied in rats with continuous infusions or bolus injections of the drugs. ... noxious pressure. The continous constant-rate infusion of alfentanil demonstrated that after an initial peak, the analgesia ... due to the development of acute tolerance. When alfentanil (250 μg·kg−1·h−1) was given ... 1), the decline in the analgesic effect of alfentanil was attenuated. Following the 4 h period of ... 250 μg·kg−1·h−1) infusion of alfentanil, when acute tolerance was already developed, midazolam (3 ...
Tópico(s): Cancer therapeutics and mechanisms
1966 - Elsevier BV | Biochemical Pharmacology
Igor Kissin, H. Ronald Vinik, Rafael Castillo, Edwin L. Bradley,
The effects of alfentanil on the midazolam dose-response curve for hypnosis was studied with response to the verbal command as an end ... patients with ASA physical status I or II. Alfentanil was found to reduce the midazolam ED50 value ... a dose-dependent fashion. The smallest dose of alfentanil (3 μg/kg) that caused a marked shift ... P < 0.0005) represents approximately 2% of the alfentanil ED50 for induction of unconsciousness (130 μg/kg). Alfentanil (10 μg/kg) caused only a tendency for ... 37% (P < 0.05). The results demonstrate that alfentanil potentiates the hypnotic effect of midazolam in very ...
Tópico(s): Pain Management and Placebo Effect
1990 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
Sheldon R. Furst, Matthew B. Weinger,
... alone and in combination with the synthetic opiate alfentanil. Spontaneously ventilating rats (n = 28) were pretreated with ... or vehicle. Fifteen minutes later all rats received alfentanil, 500 micrograms/kg. Pretreatment with dexmedetomidine reduced heart rate in a dose-related fashion. Administration of alfentanil also caused a significant reduction in heart rate. However, following alfentanil, the dexmedetomidine-treated animals did not have significantly ... dexmedetomidine, but this difference disappeared following injection of alfentanil. The addition of idazoxan to the pretreatment regimen ...
Tópico(s): Nitric Oxide and Endothelin Effects
1990 - Lippincott Williams & Wilkins | Anesthesiology
Ci-Chen Zhang, Judy Y. Su, Dianne F. Calkins,
Alfentanil causes cardiac stimulation or depression in intact animals and in clinical practice; there is no information ... the heart. Therefore, we studied the effects of alfentanil on isolated cardiac tissues from young adult rabbits. ... papillary muscle were stimulated. Isometric contraction was monitored. Alfentanil, in concentrations of 0.05-0.5 mM, ... atrial-SA node, but not in papillary muscle, alfentanil in concentrations greater than or equal to 0. ... decreased in papillary muscle by the administration of alfentanil. The time-to-50% relaxation of peak developed ...
Tópico(s): Pharmacological Effects and Assays
1990 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
Jeffrey A. Reitz, Michael B. Howie, L. J. HOFFER, Joseph J. Kryc, Janis J. MacKichan,
The pharmacokinetics and serum protein binding of alfentanil during continuous intravenous infusion were determined in 11 women who were either healthy (American Society of Anesthesiologists [ASA] physical status 1) or had ... induced with intravenous thiopental 2 mg/kg and alfentanil 50 μg/kg and maintained with constant intravenous alfentanil infusions of 1–3 μg/kg/min until ... blood samples were obtained after the bolus of alfentanil was administered and at various times during and after the alfentanil infusion. Serum alfentanil concentrations were measured by gas‐ ...
Tópico(s): Anesthesia and Pain Management
1986 - Wiley | The Journal of Clinical Pharmacology
M. Chauvin, Françis Bonnet, C. Montembault, J. C. Levron, P. Viars,
... patients undergoing intracranial surgery under neurolept anesthesia, an alfentanil infusion was initiated with a loading dose of ... was observed. A positive linear correlation existed between alfentanil steady state clearance and indocyanine green clearance (r = 0.88) and between alfentanil steady state clearance and cardiac index (r = 0. ... inserted into an hepatic vein to determine the alfentanil hepatic extraction coefficient. Alfentanil plasma clearance did not differ from alfentanil hepatic clearance and alfentanil hepatic extraction coefficient values ...
Tópico(s): Intravenous Infusion Technology and Safety
1986 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
M. E. Ausems, Carl C. Hug, Donald R. Stanski, Anton G. L. Burm,
... pharmacokinetic data, it is necessary to know the alfentanil plasma concentrations required for satisfactory anesthesia. In 37 ... abdominal, or breast surgery, anesthesia was induced with alfentanil 150 micrograms/kg iv and 66% N2O in ... anesthesia was supplemented with a continuous infusion of alfentanil that was varied between 25 and 150 micrograms ... responses to surgical stimulation. Small bolus doses of alfentanil 7 or 14 micrograms/kg were administered and ... autonomic, and hemodynamic responses. Arterial plasma concentrations of alfentanil were measured during the operation when the patient ...
Tópico(s): Nausea and vomiting management
1986 - Lippincott Williams & Wilkins | Anesthesiology
E. Gepts, Luc Heytens, F. Camu,
Alfentanil was administered as a 30 μg/kg single intravenous injection to five healthy women scheduled for ... 30 μg/kg−1/hr−1 infusion of alfentanil (group B). Five healthy nonpregnant women scheduled for minor general surgery received 120 μg/kg alfentanil intravenously as a bolus before surgical incision (group C). In groups A and B plasma alfentanil concentrations, alfentanil plasma protein binding, and α1-acid glycoprotein (α1- ... in groups A and C for measurement of alfentanil plasma concentration decay analysis indicated three-compartmental characteristics ...
Tópico(s): Cardiac, Anesthesia and Surgical Outcomes
1986 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
Audrey Shafer, Man-Ling Sung, Paul F. White,
The pharmacokinetic and pharmacodynamic properties of alfentanil were studied in 64 surgical patients. Alfentanil was administered as a loading infusion (25–130 μg/kg) followed by a maintenance infusion ( ... a nitrous oxide-narcotic-muscle relaxant technique. Although alfentanil doses of at least 50 μg/kg (in ... apnea or chest wall rigidity frequently occurred with alfentanil loading infusions exceeding 75 μg/kg. The alfentanil clearance rate was significantly lower in patients with ... of hemodynamic stability during superficial and intraabdominal operations, alfentanil serum concentration-response curves revealed ED95 values exceeding ...
Tópico(s): Nausea and vomiting management
1986 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
Ashley Webb, J.F. Doherty, Michael Chester, A.R.C. Cummin, M. Woodhead, E M Nanson, S.T. Flack, F J Millard,
... either light sedation with the short acting opiate, alfentanil (median dose 1·1 mg, range 0·5– ... gave equally good operating conditions, although patients given alfentanil coughed less than those given papaveretum and diazepam ( ... χ2 = 21·084 P < 0·001). Patients given alfentanil performed significantly better in a modified Romberg test ( ... P < 0·01) two hours after the bronchoscopy. Alfentanil produced good operating conditions, patient comfort, less cough ... either light sedation with the short acting opiate, alfentanil (median dose 1·1 mg, range 0·5– ...
Tópico(s): Anesthesia and Sedative Agents
1989 - Elsevier BV | Respiratory Medicine
Thomas K. Henthorn, Michael J. Avram, Tom C. Krejcie,
Because alfentanil has been shown to inhibit debrisoquin hydroxylase in vitro, and there is considerable variability in the reported elimination clearance of alfentanil, the possible influence of the debrisoquin metabolic phenotype on the elimination clearance of alfentanil was studied. The disposition of alfentanil was determined after rapid intravenous administration to four ... dextromethorphan/dextrorphan metabolic ratio test. The disposition of alfentanil was characterized by a three-compartment open mammillary ...
Tópico(s): Cancer therapeutics and mechanisms
1989 - Lippincott Williams & Wilkins | Anesthesiology
J. C. Ræder, Odd G. Nilsen, A. Hole,
The pharmacokinetics of alfentanil, midazolam and thiopentone used for induction of short general anaesthesia were studied in 55 gynaecological outpatients. All the patients ... as premedication. The patients received intravenous anaesthesia with alfentanil and either thiopentone or midazolam, supplemented with either ... Blood sampling for serum concentration measurements of midazolam, alfentanil and thiopentone was performed regularly for 7 h. ... s.e.mean) were calculated for midazolam and alfentanil, respectively: elimination half–life 3.9 ± 0.3 ...
Tópico(s): Anesthesia and Pain Management
1988 - Wiley | Acta Anaesthesiologica Scandinavica
P. Maitre, M. E. Ausems, Samuel Vožeh, Donald R. Stanski,
... a population pharmacokinetic analysis of the new opioid alfentanil using the computer program NONMEM. This analysis quantified ... of age, weight, and sex on disposition of alfentanil in 45 patients, and determined the average pharmacokinetic ... predict (estimate) the plasma concentration time course of alfentanil for any given dosage scheme. The present study ... these population data to predict plasma concentrations of alfentanil in a different group of surgical patients given iv boluses and a variable-rate infusion of alfentanil for induction and maintenance of anesthesia for abdominal ...
Tópico(s): Antibiotics Pharmacokinetics and Efficacy
1988 - Lippincott Williams & Wilkins | Anesthesiology
Karel Lavrijsen, Jos M. G. Van Houdt, Dirk M. J. Van Dyck, Jan Hendrickx, Robert Woestenborghs, W. Lauwers, W. Meuldermans, J Heykants,
... investigate whether the metabolism of the opiate analgesic alfentanil in humans is subject to the debrisoquine 4- ... form, debrisoquine 4-hydroxylase, in the metabolism of alfentanil was investigated by competitive inhibition experiments over the concentration range 4-100 microM. Alfentanil was incubated with human liver microsomes in the presence of an NADPH-generating system. Alfentanil and its major metabolites were quantified in the ... by reversed phase high-performance liquid chromatography (HPLC). Alfentanil was rapidly metabolized, yielding noralfentanil as the main ...
Tópico(s): Analytical Methods in Pharmaceuticals
1988 - Lippincott Williams & Wilkins | Anesthesiology
Mats Persson, Anders Nilsson, Per Hartvig,
Alfentanil was administered, together with midazolam, as part of a total i.v. anaesthetic technique. The pharmacokinetics of alfentanil were determined in 10 female patients undergoing lower abdominal surgery. The dose regimen of alfentanil, based on simulation studies, consisted of a two- ... following an initial bolus dose. The kinetics of alfentanil were described by a linear two-compartment open ... in a terminal half-life of 112 min. Alfentanil concentrations at the time of extubation and postoperative ...
Tópico(s): Nausea and vomiting management
1988 - Elsevier BV | British Journal of Anaesthesia
Max E. Auserns, Jaap Vuyk, Carl C. Hug, Donald R. Stanski,
... intravenous injections. In both cases, the intravenous opiate, alfentanil, was used to supplement nitrous oxide anesthesia, and the dose/dose-rate of alfentanil after the induction dose was guided by the ... group of ten patients received 10 mg of alfentanil and 66% N2O to induce anesthesia, and was ... given 1 or 2 mg iv doses of alfentanil whenever the depth of anesthesia was inadequate. A second group of ten patients had a target alfentanil concentration of 475 ng/ml of plasma established ... clinical signs of inadequate anesthesia. Regular measurements of alfentanil concentrations in plasma showed that the computer-assisted ...
Tópico(s): Nausea and vomiting management
1988 - Lippincott Williams & Wilkins | Anesthesiology
Jose M. den Hollander, Pim J. Hennis, Anton G. L. Burm, James G. Bovill,
The use of an alfentanil infusion as a supplement to a nitrous oxide-halothane anesthetic and the pharmacokinetics of alfentanil were evaluated in infants and children undergoing surgery ... 6%. After administration of atropine, 20 micrograms/kg, alfentanil, 20 micrograms/kg, was given, followed by a ... after closure of the sternum. Supplemental boluses of alfentanil, 5 micrograms/kg, were given when, during surgery, ... and for six hours thereafter for determination of alfentanil plasma concentrations by gas chromatography. Pharmacokinetic data were ...
Tópico(s): Cardiac Valve Diseases and Treatments
1988 - Elsevier BV | Journal of Cardiothoracic Anesthesia
Yehuda Ginosar, Elyad Davidson, Yuval Meroz, Simcha Blotnick, M. Shacham, Y. Caraco,
... determining genotype only after the procedure. I.V. alfentanil was administered by patient-controlled administration (loading dose, ... was associated with a 27% increase in plasma alfentanil concentration (P=0.034), a 54% increase in alfentanil dose (P=0.009), a 47% increase in ... failed boluses (P=0.042). Despite the increased alfentanil self-administration, the G118 SNP was associated with ... 0.047).ConclusionsWe demonstrated increased opioid requirement for alfentanil in patients with the G118 SNP, who self- ...
Tópico(s): Opioid Use Disorder Treatment
2009 - Elsevier BV | British Journal of Anaesthesia
Hyun Jeong Kwak, S. Min, Ji Young Kim, Jun‐Young Kim,
... evaluated the efficacy of a combined pretreatment of alfentanil with lidocaine on the incidence and severity of ... n=40, in each). The patients in the alfentanil group received alfentanil 15 µg kg−1 90 s before the ... The patients in the combination group received both alfentanil and lidocaine.ResultsThe incidence of propofol injection pain ( ... 6%) was significantly lower than that in the alfentanil and lidocaine groups (30% and 38.5%, respectively) ( ... the combination treatment of two different analgesic modalities, alfentanil and lidocaine, could prevent the moderate and severe ...
Tópico(s): Anesthesia and Pain Management
2009 - Elsevier BV | British Journal of Anaesthesia
James R. Miner, R. O. Gray, Dana Stephens, Michelle H. Biros,
... and recovery duration of propofol with and without alfentanil for use in procedural sedation in the emergency ... without a supplemental dose of 10 mug/kg alfentanil for deep procedural sedation. Doses, vital signs, nasal ... patients received propofol, and 71 received propofol with alfentanil. No clinically significant complications were noted. Subclinical respiratory ... group and 30/71 patients in the propofol/alfentanil group (effect size = 9.8%, 95% CI = -5. ... propofol patients and 31 of the 71 propofol/alfentanil patients (effect size 9.9%, 95% CI = -5. ...
Tópico(s): Anesthesia and Neurotoxicity Research
2009 - Wiley | Academic Emergency Medicine
Evan D. Kharasch, Harlan F. Hill, A. Craig Eddy,
... agonist clonidine has been shown to increase plasma alfentanil concentrations; however, the mechanism for this pharmacokinetic drug interaction is unknown. Because alfentanil undergoes extensive hepatic biotransformation, clonidine inhibition of alfentanil metabolism may alter alfentanil disposition. The first purpose of this investigation was ... test the hypothesis that clonidine impairs human liver alfentanil metabolism. The new highly selective alpha 2 agonist ... D-medetomidine and its levo (L) isomer on alfentanil biotransformation. Human liver microsomal alfentanil metabolism was assessed ...
Tópico(s): Antibiotics Pharmacokinetics and Efficacy
1991 - Lippincott Williams & Wilkins | Anesthesiology
W. Alan C. Mutch, K. R. A. Ringaert, F. J. Ewert, I. W. C. White, Neil Donen, Robert J. Hudson, Mary Anne K. Naugler, M. Cumming,
... in a randomized double-blind fashion; three of alfentanil and one of fentanyl. Low-dose alfentanil was administered to nine patients (35.1 μg · ... 2 μg · kg−1 · hr−1); mid -dose alfentanil to eight patients (70.2 μg · kg−1 ... 4 μg · kg−1 · hr−1); high-dose alfentanil to eight patients (105.3 μg · kg−1 ... Using published values for the pharmacokinetic variables of alfentanil and fentanyl, modelling predicted stable concentrations of 60, 120, l80 ng · ml−1 for the alfentanil infusion regimens respectively and 2 ng · ml−1 ... MAP within the prescribed limits in the low alfentanil group (ANOVA; P < 0.05). The PaCO2 at ...
Tópico(s): Pain Management and Opioid Use
1991 - Springer Science+Business Media | Canadian Journal of Anesthesia/Journal canadien d anesthésie
Ian Smith, Jan Van Hemelrijck, Paul F. White,
... undergoing ambulatory arthroscopic procedures, we compared esmolol with alfentanil when used to supplement propofol-N2O-atracurium anesthesia ... an initial intravenous dose of 16 micrograms/kg alfentanil, or 2 mg/kg of esmolol, a variable-rate infusion of alfentanil or esmolol was administered to maintain a stable ... pressure decreased to a larger extent in the alfentanil-treated patients. Although heart rate and mean arterial pressure increased in both groups after tracheal intubation, alfentanil more effectively blunted the hemodynamic response to this ...
Tópico(s): Nausea and vomiting management
1991 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
Harry J. M. Lemmens, Anton G. L. Burm, James G. Bovill, Pim J. Hennis, Marina P. R. R. Gladines,
... protein binding in relation to the pharmacodynamics of alfentanil was investigated in 15 female and 13 male ... maintained with 66% nitrous oxide in oxygen and alfentanil. Alfentanil was administered by a computer-controlled infusion pump. ... of inadequate anesthesia (i.e., response), the target alfentanil plasma concentration was increased by 50-100 ng/ ... was taken before the administration of naloxone. Plasma alfentanil concentrations were determined by capillary gas chromatography. Alfentanil protein binding was determined by equilibrium dialysis in ...
Tópico(s): Analytical Methods in Pharmaceuticals
1992 - Lippincott Williams & Wilkins | Anesthesiology
Ahmed F. Ghouri, Ellis Taylor, Paul F. White,
Study Objective: To evaluate the perioperative effects of alfentanil, midazolam, and propofol when administered using a patient- ... self-administer 2 ml bolus doses of either alfentanil 250 μg/ml, midazolam 0.4 mg/ml, ... and Main Results: The total intraoperative dosages of alfentanil, midazolam, and propofol were 2.7 ± 1.1 ... injection (39% vs. 4% and 6% in the alfentanil and midazolam groups, respectively). Episodes of arterial oxygen saturation less than 90% were more frequent with alfentanil (28%) than with midazolam (3%) or propofol (13%). ...
Tópico(s): Nausea and vomiting management
1992 - Elsevier BV | Journal of Clinical Anesthesia
Gail Winger, Paul Skjoldager, J H Woods,
... a range of doses of either cocaine or alfentanil under a fixed-ratio 30, time out 45 ... Buprenorphine suppressed responding maintained by both cocaine and alfentanil; however, much larger doses of buprenorphine were required to suppress cocaine-reinforced as opposed to alfentanil-reinforced responding. Neither cocaine nor alfentanil dose-effect curves were shifted to the right ... and nalbuphine produced similar downward shifts in both alfentanil and cocaine dose-effect curves; unlike buprenorphine, similar ...
Tópico(s): Receptor Mechanisms and Signaling
1992 - American Society for Pharmacology and Experimental Therapeutics | Journal of Pharmacology and Experimental Therapeutics
W. Andrew Kofke, Robert H. Garman, William C. Tom, Marie E. Rose, Richard A. Hawkins,
We evaluated the effect of alfentanil on hippocampal glucose utilization and histopathology associated with alfentanil-induced seizures. Three separate experiments were performed. First, anesthetized, paralyzed Long-Evans ... 30% O2continued for 1 h; (b) low-dose alfentanil (150 μg/kg IV bolus), followed by infusion ... 1 h without N2O; or (c) high-dose alfentanil (1000 μg/kg IV bolus), followed by infusion ... was injected intravenously for autoradiography. With high-dose alfentanil, there was increased glucose utilization in the ventral ...
Tópico(s): Antibiotics Pharmacokinetics and Efficacy
1992 - Lippincott Williams & Wilkins | Anesthesia & Analgesia
Christopher M. Bernards, Thomas J. Luger, Annika B. Malmberg, Harlan F. Hill, Tony L. Yaksh,
... encapsulation on the analgesia produced by intrathecally administered alfentanil was examined in the rat. In rats prepared with chronic intrathecal catheters, alfentanil in doses of 1-50 micrograms was administered ... of animals received intrathecal injections of 30 micrograms alfentanil in saline or liposomes, and blood samples were ... 45, and 135 min thereafter for measurement of alfentanil plasma concentrations. The liposome preparation markedly prolonged spinal ... liposome groups. Liposome encapsulation significantly reduced the peak alfentanil plasma concentration at 5 min and prolonged the ...
Tópico(s): Neuroscience and Neuropharmacology Research
1992 - Lippincott Williams & Wilkins | Anesthesiology
Jacqueline K. L. Hui, Lester A. H. Critchley, Manoj K. Karmakar, Patrick K. K. Lam,
... Recent studies suggest that the short-acting opioid alfentanil provides the best insertion conditions. We therefore compared the insertion conditions following co-administration of alfentanil-propofol with more commonly used fentanyl-propofol.One ... were recruited. They were randomized to receive either alfentanil (10 microg x kg(-1); n = 73) or ... and ease of insertion were not improved with alfentanil co-administration. Alfentanil-propofol reduced the incidence of swallowing, gagging, movement and laryngospasm (P < 0.05), with 29% (alfentanil) compared to 45% (fentanyl) of patients responding (P = ...
Tópico(s): Tracheal and airway disorders
2002 - Springer Science+Business Media | Canadian Journal of Anesthesia/Journal canadien d anesthésie
Stephen R. Edwards, Charles F. Minto, Laurence E. Mather,
BackgroundA ketamine–alfentanil combination has been suggested for total i.v. anaesthesia. We determined the pharmacokinetics of ketamine and alfentanil, alone and together, in three groups of adult ... in group 2, constant low plasma concentrations of alfentanil were maintained by computer-controlled infusion; in group ... gas chromatography-mass spectrometry.ResultsIn the presence of alfentanil, the mean plasma ketamine concentration–time area under ... distribution coefficients for ketamine in the presence of alfentanil were significantly higher in forebrain (by 128%, P< ...
Tópico(s): Veterinary Pharmacology and Anesthesia
2002 - Elsevier BV | British Journal of Anaesthesia