Intravenous cyclizine: expression of concerns on the gastroenterology ward round post-Christmas and the bigger picture at a university hospital

Introduction

Cyclizine is an anti-emetic drug commonly used post-surgically throughout the UK due to its anti-histamine (H1) and anti-cholinergic (anti-muscarinic M1) effects. There have been reports of cyclizine dependence and health seeking behaviours, particularly when taken intravenously, for its euphoric ('high’) or hallucinatory effects, leading to previous concerns especially in parenteral nutrition patients¹ although there are no formal prescribing guidelines.

Materials and methods

We report the experience of patients on intravenous cyclizine on our gastroenterology ward in the post-Christmas ward rounds (28–31 December). We also report the informatics picture for the ward over a year and for the wider hospital. This audit was conducted at a university tertiary teaching hospital in South Birmingham, particularly after six of the 24 (25%) gastroenterology patients were requesting intravenous cyclizine specifically. The proportion of patients prescribed cyclizine on the gastroenterology ward over the past 12 months was compared with the proportion of patients prescribed cyclizine across the hospital in a similar period. Data was extracted from the hospital's electronic prescribing system.

Results and discussion

Of the six patients, the age ranged between 23 and 55, with 50% women; half were requiring parenteral nutrition, with length of inpatient stays varying between 1 to 10 weeks. All requested intravenous cyclizine specifically with resistance to other antiemetics and/or stopping. From 1 January to 31 December 2022, 113 patients were prescribed intravenous cyclizine regular and PRN on the gastroenterology ward over the 12-month period. In total, 4,601 patients were admitted to the gastroenterology ward over the past 12 months, meaning 2.46% of patients had intravenous cyclizine prescribed. For the same period for the whole hospital, 16,100 patients admitted were prescribed IV cyclizine regular and PRN. In total, 197,804 patients were admitted to Queen Elizabeth Hospital Birmingham over the year, meaning 8.13% of patients (with the highest proportion on day case / surgical wards) had intravenous cyclizine prescribed.

Conclusion

After the surprising number of patients requesting intravenous cyclizine as part of long stays in hospital post-Christmas, we wanted to express concerns of its use in inpatients to the wider physician community. Given its widespread use in hospitals, there may well be a wider issue that needs local/national regulatory evaluation as well as quality improvements in the pharmacy/medical prescribing we are conducting.