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| The UK Society for Intravenous Anaesthesia |
| Based in the UK - as a resource for Anaesthesia Worldwide |
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Annual Scientific Meeting, Belfast; November 2000.
Remifentanil – An Update Atul Kapila Department of Anaesthesia Royal Berkshire Hospital, Reading, Berkshire When launched here in the United Kingdom in 1996 Remifentanil promised much. ‘A Truly Predictable Opioid?’ was how Carl Rosow 1 had phrased it and indeed it was. A designer drug developed in the laboratories of Glaxo (as it was then) in the Research Triangle of North Carolina – it was to change how opioids were used in anaesthesia.Remifentanil’s unique characteristic is its metabolism. A phenylpiperidine derivative and related to the other synthetic opioids fentanyl, alfentanil and sufentanil; remifentanil was given an ester linkage in the piperidine ring. Cleavage by blood and tissue esterases gives rise to metabolites that have nearly no activity at the µ receptor. Remifentanil also has small volumes of distribution. The combination of rapid clearance and a small volume of distribution produces a drug with a uniquely evanescent effect. To summarize the pharmacokinetic and pharmacodynamic differences between remifentanil and the presently available opioids:
All this and more was known before the launch of the drug 2,3,4,5. Strange then that in just over two years GlaxoWellcome (as it is now) had sold the drug to another company – Elan Pharma and furthermore had withdrawn all promotion of anaesthesia products in the United Kingdom. Where had things gone wrong? Was it a problem with the drug, the company or the end users - us the anaesthesia community? If we take an ampoule of remifentanil off the shelf from the drug cupboard and proceed to give it to a patient we can examine, along the way, some of the newer evidence that exists – both in the literature and from usage data from a district general hospital that began using remifentanil in 1997. The important considerations in the use of remifentanil are:
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