An Audit Of Missed Clozapine Doses For Patients Admitted To A Tertiary Hospital In Queensland, Australia.

• By: HAWKINS, Ellie (Royal Brisbane and Women's Hospital, Queensland Health, Australia)
• Co-author(s): Ms Ellie Hawkins (Royal Brisbane and Women's Hospital, Queensland Health, Herston, Australia)
  Mr Abdel Nayfeh (Princess Alexandra Hospital, Woolloongabba, Australia)
  Ms Lesley Smith (Princess Alexandra Hospital, Woolloongabba, Australia)
  Mr Karl Winckel (Princess Alexandra Hospital, Woolloongabba, Australia / University of Queensland, Brisbane, Australia)
  Mr Timothy Tanzer (Princess Alexandra Hospital, Woolloongabba, Australia / University of Queensland, Brisbane, Australia)
  
• Abstract:

  Background: Clozapine, an antipsychotic for treatment-resistant schizophrenia, requires strict adherence and monitoring. Interruptions to clozapine therapy from missed doses may increase the risk of psychotic relapse, serious adverse effects, and requires readmission to hospital for re-titration. Strategies must be utilised to promote the safe use of clozapine and prevent unnecessary breaks in therapy. Evaluating the administration of clozapine, a high-risk medicine, in hospitals is crucial to ensure and promote the safe and quality use of medicines.
  
  Purpose: We aimed to investigate the frequency and reason(s) for missed clozapine doses for patients admitted to hospital, the impact of psychiatry and pharmacy reviews on missed clozapine doses, and the impact of missed clozapine doses on length of stay (LOS) in hospital. We hypothesised that missed clozapine doses would occur less frequently when patients have earlier psychiatrist and pharmacist reviews, and missed clozapine doses may increase LOS.
  
  Method: A 6-month, single-site, retrospective audit was completed for patients on clozapine admitted to a tertiary hospital in Queensland, Australia. Patients prescribed clozapine during an inpatient and/or emergency department (ED) admission between 01/12/2021–31/05/2022 were included in this audit. Electronic medical record reports were used to identify eligible patients. Data collected was patient demographics; frequency and reason/s for missed doses; admitting ward; re-titration status; length of stay; time of psychiatrist and/or pharmacist review. A “missed clozapine dose” was defined as a dose not administered OR a dose ≥8 hours late. A missed clozapine dose was determined to be “accidentally missed” or “intentionally withheld” based on reason(s) for the missed dose. The audit was undertaken by one pharmacy student and four clinical pharmacists. Identifiable patient information was securely stored and accessible only by project staff. All data collected were de-identified.
  
  Results: Overall, 77 missed clozapine doses were identified (125 patient admissions); 32 patients accidentally missed a dose (n=34 doses) and 15 patients (n=43 doses) intentionally had a dose(s) withheld. Patients admitted to ED were more likely to miss a clozapine dose compared to medical/surgical or mental health wards (ED=12/30[40%]; MedSurg=11/38[29%]; MH=9/57[16%]). 82 (66%) patients had a psychiatrist review during their admission; 7 of 38 (18%) patients reviewed within 6 hours accidentally missed a dose, despite an early review by a psychiatrist. 80 (64%) patients were reviewed by a pharmacist during admission, with zero patients missing a dose thereafter. Patients re-titrating clozapine, due to missed doses, stayed in hospital for 11 days longer than patients not re-titrating (ANOVA 95% CI, 6-to-16; p<0.001; NB:analysis excluded patients initiating clozapine).
  
  Conclusion: In conclusion, we found that patients are at risk of missing clozapine doses when admitted to hospital. Our results showed that pharmacist reviews may prevent missed clozapine doses, especially when conducted early during the admission; and patients requiring re-titration due to missed doses had a significantly longer LOS. Future projects would benefit from investigating the implementation of strategies to prevent missed clozapine doses. Strategies may include providing education for junior doctors on charting stable clozapine doses on admission, implementing extended pharmacist hours in the ED, and use of clozapine alerts in a patient’s electronic medical record.