Adult Dosing
Anesthesia
- For patients with spontaneous breathing or assisted ventilation
- Induction: 8-20 mcg/kg IV x 1
- Maintenance: 3-5 mcg/kg IV q5-20 mins or 0.5-1 mcg/kg/min IV
- Total dose: 8-40 mcg/kg
Analgesic adjunct to anesthesia
Incremental injection
- Induction: 20-50 mcg/kg IV
- Maintenance of Analgesia: 5-15 mcg/kg IV q5-20 mins
- Total dose: Up to 75 mcg/kg
- Alfentanil is used to attenuate response to laryngoscopy & intubation
Analgesic adjunct to anesthesia
Continuous infusion
- Induction: 50-75 mcg/kg IV
- Maintenance of Analgesia: 0.5-3 mcg/kg/min IV (Average rate 1-1.5 mcg/kg/min)
- Max: 4 mcg/kg/min or 7 mcg/ kg as bolus to control surgical stress or lightening of anesthesia
- For ventilated patients only, use with neuromuscular blocking agent. Decrease rate by 30-50% in first hr after induction and discontinue at least 10-15 minutes prior to the end of surgery
- Provides attenuation of response to intubation and incision
Anesthesia induction
- For patients on assisted or controlled ventilation
- Induction: Start 130-245 mcg/kg IV x 1 over 3 mins
- Maintenance: 0.5-1.5 mcg/kg/min IV
- Truncal rigidity should be expected and a muscle relaxant should be utilized
Monitored anesthesia care
- For sedated, responsive, spontaneously breathing patients
- Start 3-8 mcg/kg x 1
- Maintenance of MAC: 3-5 mcg/kg q5-20 mins or 0.25-1 mcg/kg/min IV
- Max total: 3-40 mcg/kg
Pediatric Dosing
- Safety and efficacy in patients <12 yrs of age have not been established
Anesthesia
- For patients with spontaneous breathing or assisted ventilation
- Induction: 8-20 mcg/kg IV x 1
- Maintenance: 3-5 mcg/kg IV q5-20 min or 0.5-1 mcg/kg/min IV
- Total dose: 8-40 mcg/kg
Analgesic adjunct to anesthesia
Incremental injection
- Induction: 20-50 mcg/kg IV
- Maintenance of Analgesia: 5-15 mcg/kg IV q5-20 min
- Total dose: Up to 75 mcg/kg
- Alfentanil is used to attenuate response to laryngoscopy & intubation
Analgesic adjunct to anesthesia
Continuous infusion
- Induction: 50-75 mcg/kg IV
- Maintenance of Analgesia: 0.5-3 mcg/kg/min IV (Average rate 1-1.5 mcg/kg/min)
- Max: 4 mcg/kg/min or 7 mcg/ kg as bolus to control surgical stress or lightening of anesthesia
- For ventilated patients only, use with neuromuscular blocking agent. Decrease rate by 30-50% in first hr after induction and discontinue at least 10-15 minutes prior to the end of surgery
- Provides attenuation of response to intubation and incision
Anesthesia induction
- For patients on assisted or controlled ventilation
- Induction: Start 130-245 mcg/kg IV x 1 over 3 mins
- Maintenance: 0.5-1.5 mcg/kg/min IV
- Truncal rigidity should be expected and a muscle relaxant should be utilized
Monitored anesthesia care
- For sedated, responsive, spontaneously breathing patients
- Start 3-8 mcg/kg x 1
- Maintenance of MAC: 3-5 mcg/kg q 5-20 mins or 0.25-1 mcg/kg/min IV
- Max total: 3-40 mcg/kg
[Outline]
- Person specifically trained in the use of intravenous and general anesthetic agents and in the management of respiratory effect of potent opioids only should administer alfentanil. An opioid antagonist, resuscitative and intubation equipment and oxygen should be readily available
- Continue monitoring the patients well after surgery due to the possibility of delayed respiratory depression
- Alfentanil dose
130 mcg/kg can produce muscular rigidity that involves all skeletal muscles, including those of the neck and extremities. The incidence can be reduced by following routine methods of administration of neuromuscular blocking agents or simultaneous administration of alfentanil and a full paralyzing dose of a neuromuscular blocking agent or administering upto 1/4 of the full paralyzing dose of a neuromuscular blocking agent just prior to alfentanil and full paralyzing dose of a neuromuscular blocking agent after loss of consciousness - Person not involved in the conduct of the surgical or diagnostic procedure should continuously monitor patient receiving MAC. Oxygen supplementation should be readily available and provided where clinically indicated. Continuously monitor the patients for the early signs of hypotension, apnea, upper airway obstruction and or oxygen desaturation
- If alfentanil is administered to patients who have received monoamine oxidase (MAO) inhibitors within 14 days, monitor the patient and vasodilators and beta-blockers should be readily available as severe and unpredictable potentiation of MAO inhibitors has been reported for opioid analgesics
- Monitor the vital signs continuously as delayed respiratory depression, respiratory arrest, bradycardia, asystole, arrhythmias and hypotension can occur
- The dosage of alfentanil should be determined on the basis of lean body weight and should be appropriately reduced in elderly and debilitated patients. Supplemental dose should be determined on the basis of the effect of initial dose
- Alfentanil can produce loss of vascular tone and hypotension; fluid replacement prior to induction should be considered
- Administration of diazepam immediately prior to or in conjunction with high dose of alfentanil may produce vasodilation, hypotension and result in delayed recovery
- Treat bradycardia produced by alfentanil with atropine and conventional resuscitative methods
- Due to the increased risk of respiratory depression alfentanil should be used cautiously and only if clinically indicated in patients with head injury or increased intracranial pressure, as it may also obscure the clinical course of patients
- Use cautiously in patients with pulmonary disease, decreased respiratory reserve or potentially compromised respiration as alfentanil may further decrease respiratory drive and increase airway resistance. Manage it by assisted or controlled respiration during anesthesia
Cautions: Use cautiously in
- Hepatic impairment
- Renal impairment
- Pulmonary disease
- Decreased respiratory reserve
- Potentially compromised respiration
- Head injury
- Increased intracranial pressure
- Elderly or debilitated patients
- GI obstruction
- Prostatic hypertrophy
Pregnancy Category:C
Breastfeeding: Probably safe. No published experience with repeated doses of IV alfentanil. If used epidurally/intravenously during labor or for a short time immediately postpartum, amounts of alfentanil ingested by the neonate are small and would not be expected to cause any adverse effects in breastfed infants. Alternate agents might be preferred while nursing a newborn or preterm infant. Monitor infants for signs of increased sleepiness, difficulty breastfeeding, breathing difficulties, or limpness; contact a physician immediately should these occur. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 4 February 2011). As per manufacturer's data, significant levels of alfentanil were detected in colostrum four hours after administration of 60 mcg/kg of alfentanil, with no detectable levels present after 28 hours. Caution should be exercised while administering to a nursing woman.
