Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alfentanil causes cardiac stimulation or depression in intact animals and in clinical practice; there is no information concerning its direct effects on the heart. Therefore, we studied the effects of alfentanil on isolated cardiac tissues from young adult rabbits. The right atrium with sinoatrial node (SA node) was beating spontaneously, and the left atrium and papillary muscle were stimulated. Isometric contraction was monitored. Alfentanil, in concentrations of 0.05-0.5 mM, decreased by 6%-55% the frequency of contractions of the right atrial-SA node in a dose-related manner. In left atria and right atrial-SA node, but not in papillary muscle, alfentanil in concentrations greater than or equal to 0.01 mM increased the peak developed force and its maximum rate of increase. The time-to-peak developed force was prolonged in papillary muscle but not in right atrial-SA node and left atria. The maximum rate of fall of peak developed force was increased in left atria and decreased in papillary muscle by the administration of alfentanil. The time-to-50% relaxation of peak developed force was not consistently affected by alfentanil in all three muscle preparations. The same concentrations of alfentanil (greater than or equal to 0.01 mM) increased resting force in papillary muscle but not in left atria or right atrial-SA node. It is concluded that alfentanil has direct positive inotropic and negative chronotropic effects on the heart and that it causes contracture of ventricular myocardium.
 ...
PMID:Effects of alfentanil on isolated cardiac tissues of the rabbit. 239 10

Alfentanil mask anaesthesia was performed in 63 patients undergoing termination of pregnancy or curettage. Three different types of premedication were used: a) pethidine, promethazine, and atropine; b) diazepam and atropine; c) atropine. The patients were ventilated either with nitrous oxide and oxygen or with halothane and oxygen. Halothane reduced the frequency of muscular rigidity (32%; N2O 75%), postoperative sickness, and vomiting (23%; N2O 50%). On the other hand, patients regained consciousness earlier if nitrous oxide was used. Premedication a) also reduced the frequency of nausea and emesis (21%; other premedications 63%).-Alfentanil intubation anaesthesia was performed in 52 patients undergoing laparoscopy. Premedication and inhalation anaesthetic varied as described above in the group with mask anaesthesia. Muscular rigidity did not occur, and nausea/emesis were rare events (8%). Halothane prolonged the recovery phase of consciousness and respiration. Premedication a) also resulted in respiratory depression.
 ...
PMID:[Influence of various premedication agents, inhalation anesthetics and adjuvants on anesthesia with an opioid, alfentanyl]. 286 27

The pharmacokinetic and pharmacodynamic properties of alfentanil were studied in 64 surgical patients. Alfentanil was administered as a loading infusion (25-130 micrograms/kg) followed by a maintenance infusion (0.25-1.3 micrograms X kg-1 X min-1) as part of a nitrous oxide-narcotic-muscle relaxant technique. Although alfentanil doses of at least 50 micrograms/kg (in combination with thiopental, 2 mg/kg) were required to prevent hemodynamic changes during intubation, apnea or chest wall rigidity frequently occurred with alfentanil loading infusions exceeding 75 micrograms/kg. The alfentanil clearance rate was significantly lower in patients with liver dysfunction (2.3 +/- 1.3 vs 4.2 +/- 2.0 ml X kg-1 X min-1, mean +/- SD). In addition, the patients who required opioid antagonists to reverse postoperative respiratory depression had lower clearance rates (1.5 +/- 0.7 vs 4.1 +/- 1.9 ml X kg-1 X min-1) and longer elimination half-life values (406 +/- 304 vs 87 +/- 53 min). For maintenance of hemodynamic stability during superficial and intraabdominal operations, alfentanil serum concentration-response curves revealed ED95 values exceeding 300 ng/ml and 400 ng/ml, respectively. Our study also demonstrated a wide range of clinical responses to fixed doses of alfentanil. At equivalent doses, some patients required supplemental anesthetics, whereas others required an opioid antagonist. Careful titration of the alfentanil maintenance infusion is recommended to minimize the possibility of postoperative respiratory depression.
 ...
PMID:Pharmacokinetics and pharmacodynamics of alfentanil infusions during general anesthesia. 287 78

Alfentanil is a potent short-acting opioid analgesic which depresses respiration and can cause cardiovascular depression. The elderly can show greater sensitivity to opioid drugs which may be related to pharmacokinetic differences. The pharmacokinetics and clinical effects of alfentanil were studied in 10 elderly patients aged 68-86 years who were undergoing cystoscopy or urethrotomy under general anesthesia. After induction with thiopentone, and while the patient was breathing nitrous oxide with halothane 0.5% (enflurane 1.0% was given to one patient), a dose of alfentanil 4 micrograms/kg was given 15, 20, 30, 45 and 60 minutes after the alfentanil administration, and then every 30 minutes for 6 hours. Pulse rate (PR), systolic blood pressure (SBP), and minute volume (MV, calculated from the respiratory rate and the tidal volume) were measured at 1, 3, 5, 7 and 9 minutes after the alfentanil injection. Pharmacokinetic analysis showed Vc 82 (+/- S.D. 26) ml/kg; VDSS 277 (+/- S.D. 71) ml/kg; clearance 2.01 (+/- S.D. 0.64) ml/kg/min; t1/2 beta 117 (+/- S.D. 24) min. Comparison of these results with the results of other studies supports the view that older patients eliminate alfentanil less rapidly than younger patients, with prolongation of t1/2 beta and decreased clearance. The clinical results showed a decrease in minute volume from a mean value of 5944 ml before alfentanil to 1240 ml 1 minute after alfentanil (P less than 0.001). The minute volume was still significantly lower at 3 and 5 minutes, but had returned to the pre-alfentanil value by 7 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The pharmacokinetics and clinical effects of a low dose of alfentanil in elderly patients. 289 49

Alfentanil in low dosage (8 micrograms kg-1) as an analgesic agent for short duration surgery was evaluated. Forty-one women undergoing laparoscopy received double-blind either alfentanil 8 micrograms kg-1 or normal saline at induction, and all received thiopentone, alcuronium, enflurane, nitrous oxide and oxygen. The fall in mean arterial pressure (MAP) with induction was similar between groups. The MAP following intubation with alfentanil was unchanged, while with normal saline a mean rise of 23 (SD 15.2) mmHg occurred (P less than 0.001). The pulse rate following intubation showed a smaller rise (P less than 0.001) with alfentanil of 26 (SD 14.6) beats min-1, than the normal saline group of 46 (SD 13.3) beats min-1. Alfentanil was found to be a safe and effective analgesic agent in short duration surgery, by reducing sympathetic responses to intubation without cardiovascular depression or compromise of postoperative recovery.
 ...
PMID:Alfentanil for short duration laparoscopic procedures. 293 38

Opioids remain the drugs of choice for the treatment of severe pain. In recent years several new potent opioids have become available for clinical use. These newer drugs are generally safer than the older morphine-like compounds and their differing pharmacological and pharmacokinetic properties allow the physician to choose an appropriate drug according to the clinical situation and need of an individual patient. These drugs are classified according to their activity at the opioid receptors. The opioid agonists produce their pharmacological effect by an almost exclusive action at mu-receptors. The agonist-antagonist group are kappa-receptor agonists and either competitive antagonists at the mu-receptor or weak mu-agonists. The use of the potent opioid agonists, because of their potential for causing respiratory depression, is restricted to hospitals. Fentanyl, the oldest drug of this class, is extensively used as a supplement to general anaesthesia, or in high doses as a 'complete' anaesthetic for patients undergoing cardiac surgery. Alfentanil and sufentanil are newer fentanyl derivatives. Alfentanil is unique in having a very short elimination half-life. This is a particular advantage during short operations and for day-case surgery. For longer operations alfentanil can be given as a continuous infusion to supplement nitrous oxide anaesthesia. Sufentanil is about 10 times more potent than fentanyl and is more rapidly eliminated. Initial reports suggest that it may be more effective than fentanyl as an anaesthetic supplement and that recovery may be more rapid. Both sufentanil and alfentanil are also used in cardiac anaesthesia. The newer agonist-antagonist opioids, butorphanol, nalbuphine and buprenorphine, have largely replaced pentazocine in clinical practice. Unlike pentazocine, they cause a low incidence of dysphoric side effects. Like the pure agonists, they cause respiratory depression; however, in contrast to the pure agonists this is not dose related, reaching a 'ceiling' as dose increases. The risk of dependence is also less, so that these drugs are safer for the treatment of chronic pain. Additionally, it is particularly worth noting that buprenorphine and nalbuphine cause minimal cardiovascular changes, and are safe and effective drugs for treatment of pain associated with myocardial infarction. Buprenorphine, which is effective parenterally, orally and sublingually, has a prolonged duration of action (up to 12 hours after a single dose).
 ...
PMID:Which potent opioid? Important criteria for selection. 295 11

Alfentanil, a short-acting and powerful analgesic, when injected peripherally to rats (0.5 mg/kg) produced a catatonic state characterized by a rigid akinesia. The present study was designed to explore the neuroanatomical location of the opiate receptors mediating the alfentanil induced catatonia. The catatonic effect of alfentanil was measured using a bar test and depression of locomotor activity in rats tested in photocell cages during an active nocturnal phase of their cycle. Methylnaloxonium HCl (MN), a quaternary derivative of naloxone which does not readily cross the blood-brain barrier, injected into the lateral ventricle significantly reduced the catatonia at doses of 0.125-2.0 micrograms as measured in both the locomotor and bar test. MN perfusion of similar doses directly into the nucleus raphe pontis, but not in the caudate nucleus significantly antagonized the catatonia. These data complement results on alfentanil-induced muscular rigidity (Blasco et al., see companion paper) where EMG indices of rigidity in rats were reversed by microinjections of low doses of MN (0.125 and 0.5 microgram) in the nucleus raphe pontis, but not the caudate nucleus even at a high dose (4.0 micrograms). Together these results suggest that the region of the nucleus raphe pontis is an important neural substrate for opiate-induced muscular rigidity, and that the catatonic state produced by opiates depends on more diffuse opiate receptor activation of which one important component may be the nucleus raphe pontis.
 ...
PMID:'Catatonia' produced by alfentanil is reversed by methylnaloxonium microinjections into the brain. 302 82

The ventilatory response to CO2 after intravenous bolus injection of alfentanil 15 micrograms/kg was studied in a group of 10 healthy volunteers of both sexes, aged 19 to 30 years. Following randomized intravenous premedication with either placebo, diazepam 5 mg, droperidol 5 mg or etomidate 10 mg, a total of four test-series were performed with each individual in two-weekly intervals, in order to assess the additive effect of central depressants on opiate-induced respiratory depression. CO2-response curves were obtained during six-minute rebreathing periods up to 60 minutes after alfentanil. Slope as well as position of the curves were compared with pre-drug control values. In contrast to previous work with fentanyl 4 micrograms/kg, CO2-response curves after alfentanil 15 micrograms/kg were usually displaced to the right without concomitant decreases in slope. Ventilation almost completely returned to control levels after one hour. Due to strong inter- and intraindividual variations, no clearly significant differences could be observed between the premedication groups. Alfentanil plasma concentrations, determined by radioimmunoassay at 1, 3, 6, 10, 20, 30, 45, 60, 75 and 120 minutes after injection, showed only a poor correlation to the changes of the CO2-response curves.
 ...
PMID:Ventilatory CO2-response after alfentanil and sedative premedication (etomidate, diazepam and droperidol). A comparative study with human volunteers. 308 30

Alfentanil is a tetrazole derivative of fentanyl. Many of the pharmacologic effects of alfentanil are similar to those of fentanyl and sufentanil, but of quicker onset than those of fentanyl and of shorter duration than those of fentanyl and sufentanil. Alfentanil may cause less intense respiratory depression than equianalgesic doses of fentanyl. Alfentanil has a lower total body clearance, smaller volume of distribution, and shorter half-life than fentanyl and sufentanil. Clinical trials indicate alfentanil can be used effectively as an analgesic, an analgesic supplement to anesthesia, an anesthetic induction agent, and as the major component of a general anesthetic. Its short duration of effect makes it attractive as an analgesic supplement for short ambulatory surgical procedures. Alfentanil is recommended for addition to drug formularies, but its use should be restricted to anesthesia personnel.
 ...
PMID:Alfentanil in anesthesia and analgesia. 308 65

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-stage infusion following an initial bolus dose. The kinetics of alfentanil were described by a linear two-compartment open model. The total plasma clearance ranged between 93 and 431 ml min-1 (mean 249 ml min-1). The apparent volume of distribution at steady-state ranged between 0.27 and 0.64 litre kg-1 (mean 0.44 litre kg-1). The apparent volume of distribution (Vd beta) was 0.58 litre kg-1, resulting in a terminal half-life of 112 min. Alfentanil concentrations at the time of extubation and postoperative analgesic requirements were also monitored. Good correlation between respiratory depression and plasma alfentanil concentration was found. Neither lower abdominal surgery nor the simultaneous administration of midazolam seemed to affect the kinetics of alfentanil as compared with results from studies in healthy volunteers. The short half-life of alfentanil, resulting from a small volume of distribution, makes it suitable as part of a total i.v. technique. Consideration must be paid, however, to interindividual differences in the pharmacodynamic response and in plasma clearance.
 ...
PMID:Pharmacokinetics of alfentanil in total i.v. anaesthesia. 313 33


<< Previous 1 2 3 4 Next >>