the package insert of the medicine Rapifen. Therapeutic class of Anaesthetics, Systemic. Active principlesAlfentanil.
Analgesic, anesthetic for use in general anesthesia in surgical procedures of short-duration and long-duration (injections in the form of a bolus, supplemented by injections or by continuous infusion). Due to its rapid onset of action and short duration of effect, Rapifen is particularly useful as analgesic, narcotic for surgical procedures of short duration, and outpatient surgery. Also suitable as add-on analgesic in surgical procedures of medium and long duration, a time that stimuli highly painful can be easily controlled through small supplementary doses of Rapifen or by adapting the flow of the infusion. Rapifen can also be employed as an agent for the primary at the induction of anaesthesia is required endotracheal intubation and mechanical ventilation.
When should I not use?
Patients with recognized hypersensitivity to the drug or opioids in general. – Warnings: should be administered only by persons trained in the use of anesthetic agents intravenous and in the handling of the respiratory effects of opioids, potent, antagonists, opioids, such as naloxone. Equipment for resuscitation and intubation should be readily available, due to the possibility of respiratory depression late. The patient should be monitored even after the surgery. Rapifen, administered in doses the initial 20 Water/kg can cause muscle rigidity, particularly of the trunk, intensity and incidence in the general dose-dependent. Administration of Rapifen doses inducing (> 130 Water/kg) will produce muscle rigidity immediate start and more early than with other opioids. This stiffness may involve all skeletal muscles, including the neck, the extremities and muscles thorax. The incidence can be reduced by: routine administration of neuromuscular blockers; administration of up to 1/4 of the total dose paralyzing agent neuromuscular blocker, immediately before the administration of Rapifen. If you experience loss of consciousness, dose, paralyzing the total neuromuscular blocker should be administered or the simultaneous administration of Rapifen, and the dose paralyzing total neuromuscular blocker. When Rapifen is used in the doses of anesthetic administered quickly, the neuromuscular blocker should be appropriate for the state of the cardiovascular patient and appropriate equipment for respiratory depression should be available. Can occur movements mioclônicos not epileptic.
How to use?
The dose of Rapifen should be individualised according to the body weight, physical conditions, pathologies underlying, concomitant use of other drugs, type of anesthesia and length of surgical procedure. In obese patients (more than 20% increase over ideal body weight), the dose of Rapifen should be calculated based on the ideal weight. In elderly patients or debilitated, the dose of Rapifen should be reduced. In children it should be increased. The effect of the initial dose should be considered for supplementary doses. The vital signs should be monitored routine. For procedures of short duration and employment in outpatients: Rapifen in small doses is very useful in surgical procedures in small and short-lived but painful, all that is required is a good equipment for monitoring. A bolus I. V. for 7 to 15 Water/kg (1 to 2 ml/70 kg) should be sufficient for the procedures that do not exceed 10 minutes in length. When this dose is injected slowly to spontaneous breathing can be maintained in many cases. When the duration exceeds 10 minutes, and when there is a need, can be given supplementary doses of 7 to 15 Water/kg (1 to 2 ml/70 kg) each 10 or 15 minutes, as needed. To avoid bradycardia, it is recommended preferably to use I. V. small dose of an anticholinergic immediately before induction, in place of a dose I. M. as a pre-medication. In order not to prolong the recovery period, it is preferable not to administer droperidol or benzodiazepines to outpatients. In this type of patient would be the best conduct is a long-acting, induction for hypnotic short action, Rapifen and N2O/O2. When there is nausea, post-operative, it is of relatively short duration and easy to control through the measures usual. For procedures of medium duration: the initial dose I. V. bolus will be administered on the basis of an expectation of the length of the surgical procedure, based on the following: duration of surgery: 10-30 min.; Rapifen I. V. bolus: 20-40 Water/kg (3-6 ml/70 kg). Duration of surgery: 30-60 min.; Rapifen I. V. bolus: 40-80 Water/kg (6-12 ml/70 kg). Duration of surgery: > 60 min.; Rapifen I. V. bolus: 80-150 Water/kg (12-20 ml/70 kg). When surgery is more prolonged or more aggressive, the analgesia should be maintained with one of the following procedures: supplementary doses of 15 Water/kg (2 ml/70 kg) of Rapifen when required (to avoid respiratory depression post-surgery, the last dose of Rapifen should not be administered within the last 10 minutes of surgery). Infusion of Rapifen on the basis of 1 Water/kg/min. (0,14 ml/70 kg/min.) up to 5 to 10 minutes before the end of surgery. The phases of the operative painful stimuli too intense can easily be controlled by small additional doses of Rapifen or by temporarily increasing the speed of infusion. For procedures of long duration: Rapifen may be used as a component of analgesic anesthesia for surgical procedures of long duration, especially if you want a extubation quick. The optimum conditions of analgesia and stability of autonomic are maintained by a dose I. V. initial individually tailored, and by a variation in the speed of infusion according to the stimuli, surgical and the reactions of the patient’s clinical. Induction of anesthesia: a bolus of intravenous equal to or greater than 120 Water/kg (17 ml/70 kg), administered slowly (over 3 minutes), can be used as an inducer in surgeries lasting more than 45 minutes. – Overdosage: the manifestations of overdosage with Rapifen are an extension of their pharmacological effects. Depending on the individual sensitivity, the clinical picture is determined primarily by the degree of respiratory depression, which can vary from bradipnéia apnea. Treatment: in the presence of hypovolemia or obstructive sleep apnea, should be administered oxygen and respiration should be assisted or controlled. If respiratory depression is associated with muscular rigidity, may be applied to a neuromuscular blocker, I. V., to facilitate assisted or controlled ventilation. The patient should be carefully observed, the heated body conveniently and also must be maintained an adequate hydration. Occurring severe hypotension or persistent, the possibility of hypovolemia should be considered and controlled with parenteral therapy is appropriate. The antagonists narcotics-specific, such as naloxone must always be available for use in case of respiratory depression. These measures do not exclude any other considered convenient at the time.
What are the evils that can cause me?
respiratory Depression is prolonged, respiratory arrest, bradycardia, asystole, arrítmica and hypotension. Other adverse reactions recorded include hypotension, mild and transient, dizziness, nausea and vomiting, post-operative. In addition to these, other adverse reactions reported with lower frequency include: laringospasmo, bronchospasm, confusion in the postoperative period, headache, chills, euphoria in the post-operative period, hypercapnia, pain at the injection site, urticaria, and pruritus.
Warnings and Precautions
what should I know before using?
respiratory Depression, respiratory arrest, bradycardia, asystole, arrhythmias and hypotension may occur, therefore, the vital signs should be monitored continuously. The initial dose of Rapifen should be appropriately reduced in elderly and debilitated patients. In obese (more than 20% of ideal weight) the dose should be determined based on the ideal weight. In patients with compromised liver function and in geriatric patients the clearance plasma of Rapifen may be reduced and postoperative recovery delayed. The doses inducing Rapifen should be administered slowly (over 3 minutes), therefore can occur lower blood pressure and decrease of vascular tone which may require intravenous infusion of fluids before induction, especially in patients hipovolêmicos. The application of diazepam prior to or concomitantly with high doses of Rapifen may produce vasodilation, hypotension and result in a recovery to take more time. To avoid bradycardia, it is recommended to be administered intravenously with a small dose of an anticholinergic prior to induction. In case of bradycardia, it can be treated with atropine, and the cardiorespiratory arrest, with the methods of resuscitation, the usual. The hemodynamic effects of the muscle relaxant and the degree of relaxation desired, should be considered in the selection of the neuromuscular blocker. After a dose inducer of Rapifen, the needs of inhalational anesthetics or even infusion of Rapifen is reduced 30 to 50% for the first hour of maintenance. The administration of Rapifen should be discontinued at least 10 to 15 minutes before the end of surgery. The deep depresswill respiratory can be reversed with the use of an antagonist to the opioid such as naloxone, but by the fact that the depression caused of Rapifen may be more prolonged than the action of the antagonist to the opioid, care should be taken, such as, for example, to use additional doses of the antagonist, the opioid. Like all opioids, potent analgesia deep is accompanied by respiratory depression and a lower sensitivity to stimulation by CO2 which can persist during the period when the operative or use in the postoperative period. Hyperventilation intra-operative can later change the response post-operative CO2. Monitoring post-operative proper should be employed, particularly after Rapifen, in high doses, or in infusion, to ensure that a spontaneous breathing adequate has been established and maintained in the absence of stimulation. Before sending the patient to the recovery room if you wish to maintain the spontaneous respiration can, in many cases, to employ the dose of 7 Water/kg (1 ml/70 kg) or less, injected slowly; in this case the increments of dose suggested are 3.5 Water/kg (0.5 ml/70 kg). Rapifen may mask the clinical outcome of trauma of the skull in patients with compromised intracerebral. The transient decrease in mean arterial pressure occasionally it has been accompanied by a reduction in the cerebral perfusion. Rapifen should be used with caution in patients with pulmonary disease or with reserve breathing is diminished, because opioids may decrease the inspiratory flow and increase in pulmonary resistance. During anesthesia, this can be overcome with the use of assisted ventilation or controlled. In patients with renal or hepatic dysfunction, hypothyroidism not controlled or alcoholism, Rapifen should be administered with caution. Patients therapy chronic with opioids or with a history of abuse opioids may require larger doses of Rapifen. – Drug interactions: the magnitude and duration of effects on the CNS and cardiovascular system may be increased, when Rapifen is administered with other depressants central such as barbiturates, tranquilizers, other opioids, or inhaled anesthetics, and general depressants central non-selective (as for example, alcohol). The respiratory depression post-surgery may be increased or prolonged by these agents, thus, in such cases, the dose of one or both should be reduced. Clinical experience indicates that the needs of anaesthetics, volatile compounds are reduced 30 to 50% for the first 60 minutes after induction with Rapifen. The administration of perioperative medications that affect the liver blood flow or the function of enzymes (cimetidine and erythromycin) may reduce clearance the plasma and prolong the recovery, so larger doses of Rapifen should be used. It is generally recommended to suspend the use of MAO-inhibitors 2 weeks prior to any surgical procedure or anesthetic. However, there are studies in literature that report no problems in the use of fentanila, a depressor correlated during surgical procedures in patients who use MAO inhibitors. Pregnancy: the safety of the use of Rapifen in pregnancy, with respect to possible adverse effects upon fetal development, has not yet been well established, therefore, Rapifen should only be used in pregnant women when, at the discretion of the physician, the benefits outweigh the possible risks involved. It is not recommended to administer-if Rapifen via IM or IV during childbirth (including caesarean section), because Rapifen crosses the placental barrier and also because the respiratory center of the fetus is particularly sensitive to opioids. Use in lactation: has been detected in the colostrum, significant levels of Rapifen four hours after the administration of 60 Water/kg of Rapifen, not being detected the drug after 28 hours. Effects on ability to drive and operate machinery: the patient will only be able to drive cars and operate machinery when a sufficient time has elapsed after administration of Rapifen. The individual reactions are very variable. On average, the patient should wait 3 to 6 hours after receiving doses 1 to 3 ml, and 12 to 24 hours after high-dose infusion. Paediatric use: in children the dose should be increased due to the smaller volume of distribution and half-life shorter in these patients.