Alfentanil hydrochloride (Alfenta)
Pregnancy Category: C
1/2: 1-2 hr (after IV use).
Continuous infusion: As an analgesic with nitrous oxide/oxygen to maintain general anesthesia.
Incremental doses: Adjunct with barbiturate/nitrous oxide/oxygen to maintain general anesthesia.
Anesthetic induction: As primary agent when ET intubation and mechanical ventilation are necessary. Analgesic component for monitored anesthesia care.
Use during labor and in children less than 12 years of age.
Use with caution during lactation.
Additional Side Effects:
Bradycardia, postoperative confusion, blurred vision, hypercapnia, shivering, and
asystole. Neonates with respiratory distress syndrome have manifested hypotension with doses of 20 mcg/kg.
Additional Drug Interactions:
Plasma levels of alfentanil due to
breakdown of alfentanil
Indian snakeroot / Potentiation of alfentanil
Kava kava / Potentiation of alfentanil
Injection: 0.5 mg/mL
Individualize dosage and titrate to desired effect according to body weight, physical status, underlying disease states, use of other drugs, and type and duration of surgical procedure and anesthesia.
Continuous infusion, duration 45 min or more.
Initial for induction: 50-75 mcg/kg;
maintenance, with nitrous oxide/oxygen: 0.5-3 mcg/kg/min (average infusion rate: 1-1.5 mcg/kg/min). Following the induction dose, reduce the infusion rate requirement by 30%-50% for the first hour of maintenance.
Induction of anesthesia, duration 45 min or more.
Initial for induction: 130-245 mcg/kg;
maintenance: 0.5-1.5 mcg/kg/min. If a general anesthetic is used for maintenance, the concentration of inhalation agents should be reduced by 30%-50% for the first hour.
Anesthetic adjunct, 30-60 min duration, incremental injection to attenuate response to laryngoscopy and intubation.
Initial for induction: 20-50 mcg/kg;
maintenance: 5-15 mcg/kg q 5-20 min, up to a total dose of 75 mcg/kg.
Anesthetic adjunct, less than 30 min duration, incremental injection, spontaneously breathing or assisted ventilation.
Initial for induction: 8-20 mcg/kg;
maintenance: 3-5 mcg/kg q 5-20 min (or 0.5-1 mcg/kg/min, up to a total dose of 8-40 mcg/kg).
Monitored anesthesia care, less than 30 min duration, for sedated and responsive spontaneously breathing clients.
Initial for induction: 3-8 mcg/kg;
maintenance: 3-5 mcg/kg every 5-20 min (or 0.25-1 mcg/kg/min, up to a total dose of 3-40 mg/kg).
NOTE: If there is a lightening of general anesthesia or the client manifests signs of surgical stress, the rate of administration of alfentanil may be increased to 4 mcg/kg/min or a bolus dose of 7 mcg/kg may be used. If the situation is not controlled following three bolus doses over 5 min, an inhalation anesthetic, a barbiturate, or a vasodilator should be used. If signs of lightening anesthesia are noted within the last 15 min of surgery, a bolus dose of 7 mcg/kg should be given rather than increasing the infusion rate. A potent inhalation anesthetic may be used as an alternative.