4). For intravenous administration. Rapifen by the intravenous route can be administered to both adults and children. Rapifen should be used as bolus injections (short procedures) or bolus supplemented by increments or by infusion (long painful surgical procedures).
The dosage of Rapifen should be individualised according to age, bodyweight, physical status, underlying pathological condition, use of other drugs and type of surgery and anaesthesia. 5 ml) Assisted ventilation 30-50 mcg/kg 15 mcg/kg If desired, Rapifen can be mixed with sodium chloride injection BP, dextrose injection BP or compound sodium lactate injection BP (Hartmann’s solution).
Such dilutions are compatible with plastic bags and giving sets. These dilutions should be used within 24 hours of preparation. In spontaneously breathing patients, the initial bolus dose should be given slowly over about 30 seconds (dilution may be helpful).
After intravenous administration in unpremedicated adult patients, 1 ml Rapifen may be expected to have a peak effect in 90 seconds and to provide analgesia for 5-10 minutes. Periods of more painful stimuli may be overcome by the use of small increments of Rapifen.
For procedures of longer duration, additional increments will be required. In ventilated patients, the last dose of Rapifen should not be given later than about 10 minutes before the end of surgery to avoid the continuation of respiratory depression after surgery is complete.
5-1 microgram/kg/minute. Adequate plasma concentrations of alfentanil will only be achieved rapidly if this infusion is preceded by a loading dose of 50-100 microgram/kg given as a bolus or fast infusion over 10 minutes. Lower doses may be adequate, for example where anaesthesia is being supplemented by other agents.
The infusion should be discontinued up to 30 minutes before the anticipated end of surgery. Increasing the infusion rate may prolong recovery. Supplementation of the anaesthetic, if required, for periods of painful stimuli, is best managed by extra bolus doses of Rapifen (1-2 ml) or low concentrations of a volatile agent for brief periods.
Patients with severe burns presenting for dressing, etc, have received a loading dose of 18-28 mcg/kg/min for up to 30 minutes without requiring mechanical ventilation. In heart surgery, when used as a sole anaesthetic, doses in the range of 12-50 mg/hour have been used.
Paediatric patients Assisted ventilation equipment should be available for use in children of all ages, even for short procedures in spontaneously breathing children. 2). • Neonates (0 to 27 days): The pharmacokinetics are very variable in neonates, particularly in those born preterm.
Clearance and protein binding are lower, and a lower dose of Rapifen may be required. Neonates should be closely monitored and the dose of Rapifen titrated according to the response. • Infants and toddlers (28 days to 23 months): Clearance may be higher in infants and toddlers compared to that in adults.
For maintenance of analgesia, the rate of infusion of Rapifen may need to be increased. • Children (2 to 11 years): Clearance may be slightly higher in children and the rate of infusion may need to be increased. • Adolescents: The pharmacokinetics of alfentanil in adolescents are similar to those in adults and no specific dosing recommendations are required.
Dosing recommendations for paediatric patients The wide variability in response to Rapifen makes it difficult to provide dosing recommendations for younger children. e. to supplement propofol or inhalation anaesthesia) or as an analgesic is considered appropriate.
Supplemental boluses of 5 to 10 mcg/kg Rapifen at appropriate intervals can be administered. 5 to2 mcg/kg/min may be administered. The dose must be titrated up or down according to the needs of the individual patient. When combined with an intravenous anaesthetic agent the recommended dose is approximately 1 mcg/kg/min.
There may be a higher risk of respiratory complications and muscle rigidity when Rapifen is administered to neonates and very young children. Necessary precautions are detailed in section