Analgetic for use during the induction and / or maintenance of general anesthesia during surgical procedures (including cardiosurgical). Treatment of pain in the immediate postoperative period in patients under close medical care prior to the use of long-acting painkillers. Anesthesia and sedation of mechanically ventilated patients in intensive care units.
Composition:
1 vial contains 1 mg, 2 mg or 5 mg of remifentanil as hydrochloride.
Action:
A selective μ-opioid receptor agonist characterized by rapid onset and very short duration of action. After intravenous administration, the analgesic effect occurs almost immediately and disappears after a few minutes after the end of the infusion, and residual opioid activity persists for no more than 10 minutes. Within the range of the recommended dosage, the concentration of the drug in the blood is proportional to the dose; increasing the infusion rate by 0.1 μg / kg / min increases the plasma concentration by 2.5 ng / ml. It shows clinical activities typical of opioids, including a significant inhibitory effect on the respiratory center. It does not cause the release of histamine or the effect of recurrent inhibition of the respiratory center. It binds plasma proteins to an average of 70%. Metabolized by nonspecific blood and tissue esterases for virtually inactive (1/4600 potency of remifentanil) carboxylic acid. Remifentanil is not a substrate for plasma cholinesterase. T0,5 remifentanil is 3-10 min, the metabolite is 2 h. Approximately 95% of the remifentanil is excreted in the urine as a metabolite. The clearance and volume of distribution of remifentanil at steady state is increased in young children, then decreases with age, reaching approximately 17 years of age as in adults. The pharmacokinetics of the carboxyl metabolite in children (2-17 years) is not different from adults; T0,5 Remifentanil is not significantly different in infants. The pharmacodynamic effect of the drug increases with age: in patients over 65 years, the clearance is reduced by 25% and the effective concentration is reduced by 50%. The pharmacokinetics of remifentanil are not significantly altered in patients with varying degrees of renal failure even after administration for 3 days under intensive care. The elimination of the carboxylic metabolite is reduced in patients with renal insufficiency, the accumulation does not cause significant μ-opioid effects even after 3 days of infusion. The pharmacokinetics of remifentanil are unchanged in patients with severe hepatic dysfunction and during the "non-hepatic" phase of liver transplant surgery. Patients with severe hepatic impairment may be slightly more sensitive to the inhibitory effect of remifentanil on the respiratory center. In hypothermic patients (in cardio-anesthesia), clearance of remifentanil decreases by about 3% for every 1st C. lower body temperature. There is no evidence of remifentanil removal during dialysis; the carboxylic metabolite is removed at approx. 30% during hemodialysis.
Contraindications:
Hypersensitivity to fentanyl derivatives or other ingredients of the preparation. Do not use epidural or subarachnoid (the preparation contains glycine). The use of the preparation as the only agent for general anesthesia is contraindicated.
Precautions:
The drug can only be used by people who are experienced in the use of anesthetics, assisted ventilation and resuscitation, in conditions that enable monitoring and support of circulation and breathing. The drug may cause muscle stiffness, usually depending on the dose and speed of administration (a single injection should last> 30 sec), which can be controlled by a decrease in the infusion rate (disappears within a few minutes after stopping the supply). If necessary, use breathing assistance. It has an inhibitory effect on the respiratory center - unintentional hypoventilation prevents the reduction of the infusion by 50%. May cause hypotension and bradycardia, caution should be used in patients with debilitated, hypovolaemic and elderly patients due to the increased sensitivity of these groups of patients to the influence of remifentanil on the cardiovascular system.Due to the very rapid disappearance of remifentanil (5-10 minutes after the end of the infusion, no residual opioid activity is observed), in patients undergoing surgical procedures followed by postoperative pain, analgesics should be administered before or immediately after completion of the infusion. It should be noted that unintentional (after completion of the infusion) administration of the drug from the volume of the drain which was used. Like other opioids, remifentanil can cause addiction.
Pregnancy and lactation:
There are no studies on the safety of remifentanil in pregnant women. The drug can be used in pregnant women only in cases where the expected benefit to the mother outweighs the potential risk to the fetus. The safety profile of the medicine during delivery has not been established. There is insufficient data to recommend the use of the drug during labor or Caesarean section. The drug crosses the placenta barrier (fetal blood concentration is about 50% in the maternal blood) and is likely to be metabolized in the fetus (may have an inhibitory effect on the newborn's respiratory center). Nursing mothers should be advised to stop breastfeeding for 24 hours after using the drug - fentanyl derivatives are excreted in human milk.
Side effects:
Very common: skeletal muscle rigidity, hypotension, nausea, vomiting. Common: bradycardia, increase in blood pressure in the postoperative period, acute respiratory depression, apnea, pruritus, postoperative shivering. Uncommon: hypoxia, constipation, postoperative pain. Rare: sedation during recovery from general anesthesia, allergic reactions with anaphylaxis including patients receiving remifentanil in combination with other general anesthetics, asystole, cardiac arrest, usually preceded by bradycardia (when administering remifentanil with other general anesthetics). In addition: addiction, convulsions, atrioventricular block, tolerance. In rare cases, tachycardia, hypertension and agitation were observed after sudden discontinuation of remifentanil, in particular if this occurred after prolonged administration (longer than 3 days).
Dosage:
Intravenously. Adults: Introduction to anesthesia (always with an anesthetic agent): 0.5-1.0 μg / kg infusions / min preceded or not by bolus 1.0 μg / kg; maintenance of anesthesia in ventilated patients: in anesthesia with 66% N20 - initially 0.4 μg / kg bw / min, then 0.1-2.0 μg / kg bw / min; in anesthesia with isoflurane (0.5 MAC) or propofol (100 μg / kg / min) - initially 0.25 μg / kg / min, then 0.05-2.0 μg / kg / min . The clinical effect is decisive, the infusion rate should be increased by 25-100% or decreased by 25-50% every 2-5 min; You can add a bolus every 2-5 minutes. Anesthesia with maintained own breath: the initial infusion rate is 0.04 μg / kg / min, then it can be adjusted depending on the desired effect (0.025-0.1 μg / kg / min); it is not recommended to administer the medicine in a single injection. Continuation of analgesia in the immediate postoperative period while maintaining the patient's own breath (until the analgesic effect given early in the analgesic with long duration of action): initial infusion of 0.1 μg / kg / min, then increased or decreased by 0.025 μg / kg. / min at 5-minute intervals; use in a single injection is not recommended. In patients: in the elderly - there may be more sensitivity to the drug, reduce the initial doses by 50%; in patients with III / IV operational risk group acc. ASA should reduce the initial dose; in overweight patients, the dose should be calculated according to due to mc. It is not necessary to modify the doses in renal or hepatic failure. Dosage in children: until 1 year of age - no research on recommending doses. The pharmacokinetics of remifentanil in neonates and infants is similar to that seen in adults. At the age of 1-12: no studies to determine the dosage for anesthesia. Maintenance of anesthesia in children 1-12 years: single injection of 1.0 μg / kg / min + continuous infusion of remifentanil + anesthetic administered in a mixture of2/ N2O = 1: 2. With halothane (0.3 MAC): initial dose - 0.25 μg / kg / min, maintenance dose - 0.05-1.3 μg / kg bw / min; with sevoflurane (0.3 MAC): initial dose - 0.25 μg / kg / min, maintenance dose - 0.05-0.9 μg / kg / minute; with isoflurane (0.5 MAC) - initial dose - 0.25 μg / kg bw / min, maintenance dose - 0.06-0.9 μg / kg bw / min; Adult cardio-anesthesia: induction - it is not recommended to use the drug in a single injection, start the infusion of 1.0 μg / kg / min and do not intubate before 5 min. Maintenance of anesthesia in patients ventilated in anesthesia with isoflurane (0.4 MAC) - single injection of 0.5-1.0 μg / kg. + initially 1.0 μg / kg bw / min, then in the range 0.003-4.0 μg / kg bw / min; in anesthesia with propofol at an initial dose of 50 μg / kg / min - a single injection of 0.5-1.0 μg / kg. + initially 1.0 μg / kg bw / min, then in the range of 0.01-4.3 μg / kg bw / min; continuation of anesthesia: single injection - not recommended; infusion in the range of 0-1.0 μg / kg bw / min. Cardiovestesis of children: no data available for administration of recommended doses. Intensive adult therapy - as a medicine for sedation and analgesia in mechanically ventilated patients - an infusion of 0.1-0.15 μg / kg / min; the infusion rate should be modified (increased) by 0.025 μg / kg / min, no more frequently than every 5 min to achieve the desired level of sedation / anesthesia; before the treatments associated with pain stimulation, it is recommended to maintain the infusion rate at a minimum of 0.1 μg / kg / min for 5 min, with the possible increase in the dose by 25-50% every 2-5 min. No experience regarding long-term use in intensive care in children <18 yrs. It should only be injected intravenously using a calibrated infusion pump into a high-flow infusion tube or a separate cannula connected to the intravenous line. It is recommended to use dilutions: adults - 50 μg / ml, children> 1 year of age - 20-25 μg / ml. Detailed dosing rules, including in combination with sedative medicines, are included in the informational materials on the medicine.