Blood Draw Barriers for Treatment with Clozapine and Development of a Point-of-Care Monitoring Device

Kelly, Deanna L.; Ben‐Yoav, Hadar; Payne, Gregory F.; Winkler, Thomas; Chocron, Sheryl E.; Kim, Eunkyoung; Kitchen, Christopher; Stock, Veronika M.; Vyas, Gopal; Love, Raymond C.; Wehring, Heidi J.; Sullivan, Kelli; Feldman, Stephanie; Liu, Fang; McMahon, Robert P.; Ghodssi, Reza

doi:10.3371/csrp.kebe.070415

Cited by 32 publications

(33 citation statements)

References 11 publications

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“…As illustrated in Figure 1a, the challenge to clinicians is that serum clozapine levels cannot be adequately controlled by dosage because of variabilities in drug metabolism (Couchman et al, 2013; Rajkumar et al, 2013; Rostami-Hodjegan et al, 2004). A recent survey indicated that clozapine would be more broadly prescribed if serum levels could be rapidly measured at the point-of-care (POC) to provide clinicians with the timely information required to adjust dosages (Kelly et al, 2015). …”

Section: Introductionmentioning

confidence: 99%

Reliable clinical serum analysis with reusable electrochemical sensor: Toward point-of-care measurement of the antipsychotic medication clozapine

Kang

Kim

Winkler

et al. 2017

Biosensors and Bioelectronics

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Clozapine is one of the most promising medications for managing schizophrenia but it is under-utilized because of the challenges of maintaining serum levels in a safe therapeutic range (1–3 μM). Timely measurement of serum clozapine levels has been identified as a barrier to the broader use of clozapine, which is however challenging due to the complexity of serum samples. We demonstrate a robust and reusable electrochemical sensor with graphene-chitosan composite for rapidly measuring serum levels of clozapine. Our electrochemical measurements in clinical serum from clozapine-treated and clozapine-untreated schizophrenia groups are well correlated to centralized laboratory analysis for the readily detected uric acid and for the clozapine which is present at 100-fold lower concentration. The benefits of our electrochemical measurement approach for serum clozapine monitoring are: (i) rapid measurement (≈ 20 min) without serum pretreatment; (ii) appropriate selectivity and sensitivity (limit of detection 0.7 μM); (iii) reusability of an electrode over several weeks; and (iv) rapid reliability testing to detect common error-causing problems. This simple and rapid electrochemical approach for serum clozapine measurements should provide clinicians with the timely point-of-care information required to adjust dosages and personalize the management of schizophrenia.

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Section: Introductionmentioning

confidence: 99%

Reliable clinical serum analysis with reusable electrochemical sensor: Toward point-of-care measurement of the antipsychotic medication clozapine

Kang

Kim

Winkler

et al. 2017

Biosensors and Bioelectronics

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“…Psychotic fears and feelings, such as the fear of being fleeced or the denial of suffering from any psychotic illness at all, can interfere with and hamper regular blood sampling in the more severely affected inpatient population. Making the blood sampling procedure easy in its execution and in its accessibility can contribute to greater patient compliance .…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the performance of a point‐of‐care method for total and differential white blood cell count in clozapine users

Bui

Bogers

Cohen

et al. 2016

Int J Lab Hematology

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The point-of-care device can be used to screen for leukocyte and neutrophil counts. Because of the relatively high measurement uncertainty and poor correlation with venous samples, we recommend to repeat the measurement with a venous sample if cell counts are in the lower reference range. In case of clozapine therapy, neutropenia can probably be excluded if high neutrophil counts are found and patients can continue their therapy.

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“…8,9 Some of this stems from the challenge of coordinating laboratory, pharmacy, and clinic visits and the extra time required to monitor laboratory results. 10 The fractured nature of community care amplifies these challenges. Clinician reluctance also stems from clozapine’s medical risks, especially agranulocytosis.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Safety of Clozapine Use in Patients With Benign Neutropenia

Richardson

Davis

Vyas

et al. 2016

J. Clin. Psychiatry

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Objective Determine if clozapine can be safely utilized in a population of psychiatric patients with current or a history of benign neutropenia. Method A single-center, retrospective chart review was conducted in an inpatient psychiatric hospital. Patients included had benign neutropenia prior to receiving clozapine and received clozapine using modified monitoring guidelines. All available laboratory values for absolute neutrophil count (ANC) before clozapine initiation and during treatment were evaluated. The primary endpoint was the difference in ANC after initiation of clozapine compared to before clozapine treatment. Results A total of 26 patients were reviewed. Mean age was 34 years at clozapine initiation. The majority were African-American (73%), with more males than females (73% vs. 27%). The mean lowest ANC value was not significantly different after clozapine initiation compared to before (1.5 and 1.4×103 cells/mm3, respectively; p=0.22). There were no cases of agranulocytosis (ANC <0.5 ×103 cells/mm3) and no patients were discontinued for falling below limits set by modified guidelines. There were fewer occurrences of mild neutropenia (ANC <2.0×103 cells/mm3) after clozapine initiation than before (16% and 31.4%, respectively; p<0.001). There were also fewer occurrences of moderate neutropenia (ANC <1.5×103 cells/mm3) with 2.1% after clozapine and 13.3% before (p<0.001). Occurrence of ANC <1.0×103 cells/mm3 did not differ (0.4% before, 0.3% after, p=0.79). Conclusion Twenty-six patients with benign neutropenia were safely treated with clozapine. Their pre-clozapine neutropenia did not predict increased risk for agranulocytosis with clozapine. Patients had significantly fewer episodes of mild and moderate neutropenia after receiving clozapine compared to before.

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Blood Draw Barriers for Treatment with Clozapine and Development of a Point-of-Care Monitoring Device

Cited by 32 publications

References 11 publications

Reliable clinical serum analysis with reusable electrochemical sensor: Toward point-of-care measurement of the antipsychotic medication clozapine

Reliable clinical serum analysis with reusable electrochemical sensor: Toward point-of-care measurement of the antipsychotic medication clozapine

Evaluation of the performance of a point‐of‐care method for total and differential white blood cell count in clozapine users

Evaluation of the Safety of Clozapine Use in Patients With Benign Neutropenia

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