RAPIFEN

What it is

RAPIFEN contains alfentanil, a potent, short-acting opioid analgesic chemically related to fentanyl. Each mL of alfentanil injection contains alfentanil hydrochloride equivalent to 0.5 mg alfentanil with 9.0 mg sodium chloride in water for injection. RAPIFEN is a sterile, clear and colourless solution for injection.

Approved indications

RAPIFEN is indicated for intravenous use by specialist anaesthetists and their trainees as: — An analgesic supplement given by incremental intravenous boluses or continuous infusion — An anaesthetic induction agent in patients undergoing in-patient surgery, when endotracheal intubation and controlled ventilation are to be used

Dosing overview

Dosage should be individualised taking into consideration factors such as age, body weight, physical status, underlying pathological condition, use of other medicines, type of anaesthesia to be used and type and duration of the surgical procedure. As a general principle, the lowest effective dose should be used. For analgesic supplement use with spontaneous ventilation techniques, doses up to 7 micrograms per kilogram, administered as a slow intravenous injection, may be used with increments of 2–3 micrograms per kilogram at 10–15 minute intervals. For controlled ventilation techniques, a dose prior to intubation of 20–50 micrograms per kilogram is appropriate for attenuation of the hypertensive response to laryngoscopy. For short procedures, an initial dose of 7–15 micrograms per kilogram at induction, with intermittent boluses up to 15 micrograms per kilogram at 10–15 minute intervals is most useful. An intravenous bolus dose of at least 120 micrograms per kilogram will induce hypnosis and analgesia while maintaining good cardiovascular stability in patients with adequate muscle relaxation when used as an induction agent. The initial dose of alfentanil should be appropriately reduced in the elderly (older than 65 years of age) and in cirrhotic patients.

Key safety warnings

Serious, life-threatening or fatal respiratory depression may occur with the use of alfentanil. Be aware of situations which increase the risk of respiratory depression, modify dosing in patients at risk and monitor patients closely, especially on initiation or following a dose increase. Because of the possibility of delayed respiratory depression, monitoring of the patient must continue well after surgery in an approved recovery facility. Concomitant use of opioids with benzodiazepines, gabapentinoids, antihistamines, tricyclic antidepressants, antipsychotics, cannabis or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Patients should be cautioned not to drink alcohol while on alfentanil. Alfentanil poses risks of hazardous and harmful use which can lead to overdose and death. Assess the patient's risk of hazardous and harmful use before prescribing and monitor the patient regularly during treatment. Addiction can occur in patients appropriately prescribed alfentanil at recommended doses. The risk of addiction is increased in patients with a personal or family history of substance abuse (including alcohol and prescription and illicit drugs) or mental illness. The risk also increases the longer the drug is used and with higher doses. Alfentanil, also at doses below 20 micrograms per kilogram, may cause skeletal muscular rigidity, particularly of the truncal muscles. The incidence and severity of muscular rigidity is usually dose related. Administration of alfentanil at anaesthetic induction dosages (above 120 micrograms per kilogram) will consistently produce muscular rigidity with an immediate onset.

Contraindications

RAPIFEN is contraindicated in those with a known intolerance to the medicine, components of the formulation or to other opioid analgesics. RAPIFEN is contraindicated in post-operative analgesia. RAPIFEN is contraindicated for use in patients with severe respiratory disease, acute respiratory disease and respiratory depression. RAPIFEN is contraindicated for use in chronic (long-term) non-cancer pain (CNCP).

Regulatory history

RAPIFEN alfentanil 5 mg per 10 mL injection and alfentanil 1 mg per 2 mL injection were first registered on the Australian Register of Therapeutic Goods on 14 October 1994.