Biomaterial Database

Dried Blood Spot Analysis for Therapeutic Drug Monitoring of Clozapine. 2017

Lisanne M Geers, and Dan Cohen, and Laura M Wehkamp, and Kai van Hateren, and Remco A Koster, and Olga Yu Fedorenko, and Arkadyi V Semke, and Nikolay Bokhan, and Svetlana A Ivanova, and Jos G W Kosterink, and Anton J M Loonen, and Daan J Touw

Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

Schizophrenia is a psychiatric disorder that affects approximately 0.4%-1% of the population worldwide. Diagnosis of schizophrenia is based primarily on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. Clozapine is an antipsychotic drug that is mainly used in the treatment of schizophrenia patients who are refractory or intolerant to at least 2 other antipsychotics. Due to the high variability in pharmacokinetics of clozapine, therapeutic drug monitoring (TDM) is highly recommended for clozapine therapy. To develop and clinically validate a novel sampling method using dried blood spot (DBS) to support TDM of clozapine and norclozapine. From June 2014 to September 2014, 15 schizophrenia patients (18-55 years) treated with clozapine were included. Plasma, DBS samples made from venous samples (VDBS), and finger prick DBS (DBS) samples were obtained before administration and 2, 4, 6, and 8 hours after clozapine intake. The study was repeated in 6 Russian patients for external validation. Passing-Bablok regression and Bland-Altman analysis were used to compare the DBS, VDBS, and plasma results for clozapine and norclozapine. The DBS validation results showed good linearity over the concentration time curve measured for clozapine and norclozapine. The accuracy and between- and within-day precision variation values were within accepted ranges. Different blood spot volumes and hematocrit values had no significant influence on the results. The DBS samples were stable at 20°C and 37°C for 2 weeks and at -20°C for 2 years. The mean clozapine and norclozapine DBS/plasma ratios were, respectively, 0.80 (95% CI, 0.76 to 0.85) and 1.063 (95% CI, 1.027 to 1.099) in Dutch patients. The mean clozapine DBS/DPS ratio in Russian patients was 0.70 (95% CI, 0.64 to 0.76). DBS analysis is a reliable tool for blood sampling and performing TDM of clozapine and norclozapine in daily practice and substantially extends the opportunities for TDM of clozapine.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D003024	Clozapine	A tricylic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2A/2C receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent.	Clozaril,Leponex
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012559	Schizophrenia	A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.	Dementia Praecox,Schizophrenic Disorders,Disorder, Schizophrenic,Disorders, Schizophrenic,Schizophrenias,Schizophrenic Disorder
D014150	Antipsychotic Agents	Agents that control agitated psychotic behavior, alleviate acute psychotic states, reduce psychotic symptoms, and exert a quieting effect. They are used in SCHIZOPHRENIA; senile dementia; transient psychosis following surgery; or MYOCARDIAL INFARCTION; etc. These drugs are often referred to as neuroleptics alluding to the tendency to produce neurological side effects, but not all antipsychotics are likely to produce such effects. Many of these drugs may also be effective against nausea, emesis, and pruritus.	Antipsychotic,Antipsychotic Agent,Antipsychotic Drug,Antipsychotic Medication,Major Tranquilizer,Neuroleptic,Neuroleptic Agent,Neuroleptic Drug,Neuroleptics,Tranquilizing Agents, Major,Antipsychotic Drugs,Antipsychotic Effect,Antipsychotic Effects,Antipsychotics,Major Tranquilizers,Neuroleptic Agents,Neuroleptic Drugs,Tranquillizing Agents, Major,Agent, Antipsychotic,Agent, Neuroleptic,Drug, Antipsychotic,Drug, Neuroleptic,Effect, Antipsychotic,Major Tranquilizing Agents,Major Tranquillizing Agents,Medication, Antipsychotic,Tranquilizer, Major
D016903	Drug Monitoring	The process of observing, recording, or detecting the effects of a chemical substance administered to an individual therapeutically or diagnostically.	Monitoring, Drug,Therapeutic Drug Monitoring,Drug Monitoring, Therapeutic,Monitoring, Therapeutic Drug