Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Ultiva (Glaxo Wellcome)
vials containing 1 mg, 2 mg and 5 mg powder for reconstitution
AMH Section 3.2
Opioid analgesics are often used during general anaesthesia. Remifentanil is an opioid agonist with a structure related to fentanyl.
An infusion of remifentanil rapidly produces analgesia. It can be used as an adjunct during induction and during the maintenance of anaesthesia when endotracheal intubation and controlled ventilation are planned.
Remifentanil is rapidly metabolised by circulating and tissue esterases. It has a half-life of 3-10 minutes and a rapid offset of action. The effect of the drug usually wears off within 5-10 minutes. As remifentanil is not approved for postoperative analgesia, another analgesic should be given before the infusion is stopped.
Like other opioids, remifentanil can cause respiratory depression, hypotension and bradycardia. These can be managed by reducing the rate of infusion, but the drug should not be used for spontaneous ventilation anaesthesia.
A rapid onset of action can be associated with muscle rigidity. If a bolus dose is used during induction, it should be given slowly over a minute. To avoid giving a bolus during infusions, a dedicated intravenous line or fast-flowing intravenous line is recommended.
The pharmacokinetics of remifentanil offer some advantages over other opioid agonists. However, anaesthetists will need to be alert to the potential adverse effects, particularly if the drug is used during induction. Its use as a sole agent in general anaesthesia is contraindicated.