Subcutaneous cyclizine

Abstract

We have recently introduced a policy of using subcutaneous cannula analgesia for postoperative pain management in patients in whom patient-controlled analgesia or epidural analgesia is not indicated. Advantages include avoiding further injections to the patient and potential needlestick injuries to staff; but also, compared to the intramuscular route, patients have expressed a strong preference for the subcutaneous route of administration [1]. Morphine is our opioid of choice and is licensed for subcutaneous injection. Cyclizine is a long-established anti-emetic [2] and has been shown to reduce the risk of postoperative nausea and vomiting associated with patient-controlled analgesia [3]. Having used cyclizine lactate as a subcutaneous injection in other hospitals, it seemed logical to prescribe this agent for postoperative use on the wards. However, it was brought to our attention by the ward nursing staff that this was an unlicensed route of administration. We contacted the manufacturers (GlaxoWellcome) who informed us that, although the data sheet only recommends intravenous or intramuscular injection, they were aware that cyclizine was frequently administered by the subcutaneous route. They were unable to quote a reference relating to peri-operative use but quoted a number of publications relating to use in palliative care [4, 5]. Indeed, the palliative care formulary in our own hospital lists cyclizine as available for subcutaneous injection or infusion. We decided to conduct an audit to determine whether there were any local problems with the use of subcutaneous cyclizine. Over approximately 2 months, 92 patients received an intra-operative injection of cyclizine 50 mg via a subcutaneous cannula. Patients were reviewed in recovery by the recovery nursing staff and then at 24 h by the acute pain sister (J.D.). Patients were asked if there was any discomfort or pruritus at the injection site and the site itself was inspected for any erythema or skin changes. By 24 h some patients had also received a subcutaneous dose of morphine sulphate. The results showed a small incidence of very minor side-effects (Table 4). We believe that cyclizine lactate is a versatile agent for the management of postoperative nausea and vomiting. Indeed, following the withdrawal of droperidol, the administration of cyclizine via an indwelling subcutaneous cannula provides a useful anti-emetic alternative and could be adopted more widely.