Reply from Clozaril Patient Monitoring Service

O'Sullivan, D; Lynch, K P

doi:10.1136/bmj.313.7067.1262a

Cited by 6 publications

(1 citation statement)

References 2 publications

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“…Concerning the first issue, the haematological thresholds originally used by the clozapine patent holder appear to have been set with a margin of safety. However, the manufacturers have since acknowledged that these limits were arbitrarily defined and are not consistent with clinical and scientific knowledge of immune system functioning, and therefore may unnecessarily restrict access to treatment (O'Sullivan and Lynch, 1996). Regarding the second issue, shortly after the aforementioned events in Finland, a Sandoz-sponsored article proposed weekly haematological monitoring for the first 18 weeks, similar to previous recommendations for chlorpromazine (Pisciotta et al ., 1958; Amsler et al ., 1977; Anderman and Griffith, 1977).…”

Section: Discussionmentioning

confidence: 99%

Clozapine haematological monitoring for neutropenia: a global perspective

Oloyede

Blackman

Whiskey

et al. 2022

Epidemiol Psychiatr Sci

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Aims Clozapine is licensed for treatment-resistant psychosis and remains underutilised. This may berelated to the stringent haematological monitoring requirements that are mandatory in most countries. We aimed to compare guidelines internationally and develop a novel Stringency Index. We hypothesised that the most stringent countries would have increased healthcare costs and reduced prescription rates. Method We conducted a literature review and survey of guidelines internationally. Guideline identification involved a literature review and consultation with clinical academics. We focused on the haematological monitoring parameters, frequency and thresholds for discontinuation and rechallenge after suspected clozapine-induced neutropenia. In addition, indicators reflecting monitoring guideline stringency were scored and visualised using a choropleth map. We developed a Stringency Index with an international panel of clozapine experts, through a modified-Delphi-survey. The Stringency Index was compared to health expenditure per-capita and clozapine prescription per 100 000 persons. Results One hundred twocountries were included, from Europe (n = 35), Asia (n = 24), Africa (n = 20), South America (n = 11), North America (n = 7) and Oceania and Australia (n = 5). Guidelines differed in frequency of haematological monitoring and discontinuation thresholds. Overall, 5% of included countries had explicit guidelines for clozapine-rechallenge and 40% explicitly prohibited clozapine-rechallenge. Furthermore, 7% of included countries had modified discontinuation thresholds for benign ethnic neutropenia. None of the guidelines specified how long haematological monitoring should continue. The most stringent guidelines were in Europe, and the least stringent were in Africa and South America. There was a positive association (r = 0.43, p < 0.001) between a country's Stringency Index and healthcare expenditure per capita. Conclusions Recommendations on how haematological function should be monitored in patients treated with clozapine vary considerably between countries. It would be useful to standardise guidelines on haematological monitoring worldwide.

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