Response to Donepezil, Drug Plasma Concentration and the CYP2D6 and APOE Genetic Polymorphisms

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Total Enrollment

37 participants

Study Classification

OBSERVATIONAL

Study Start Date

2009-06-30

Study Completion Date

2013-03-31

Brief Summary

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Pharmacological treatment of AD is currently based on cholinesterase inhibitors (ChEI) and memantine, which have been shown to lead to modest, although effective, clinical benefits. Donepezil is a ChEI metabolized through the cytochrome P (CYP) 450, primarily by the 3A4 and 2D6 isoforms. The CYP2D6 gene presents polymorphisms that can alter its expression. The plasma therapeutic level ranges from 30 to 75 ng/mL, and 50% of acetylcholinesterase inhibition is achieved when the concentration reaches 15.6 ng/mL. An optimal plasma level is greater than 50 ng/mL.

These polymorphisms may influence the individual's response to treatment with donepezil and the concentration of the drug in AD patients, without achieving the desired effect. However, most of the individuals are EM, i.e., the metabolism of the drug occurs according to the expected kinetics and is associated with the presence of one or two wild-type alleles.

Objective: investigate the pattern of clinical response to donepezil in a group of patients with AD and AD with cerebrovascular disease (CVD) in relation to the plasmatic concentration of donepezil and polymorphisms of the CYP2D6 and apolipoprotein E (APOE) genes.

Detailed Description

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Patients taking donepezil were seen four times (from June 2009 to March 2013) and were submitted to the MMSE test, the Consortium to Establish a Registry for Alzheimer'sDisease battery (CERAD), and the Pfeffer Functional Activities Questionnaire. CERAD memory evaluation was further divided into five components: incidental recall (CERAD151 INC), immediate recall 1 and 2 (CERAD-RM1, CERAD-RM2, respectively) and delayed recall after five minutes (CERAD-R). Each aspect was analyzed individually and compared between groups at baseline and after 12 months of treatment with donepezil. All patients had blood samples (10mL) collected to obtain donepezil plasmatic concentration (DPC) measurements and for APOE and CYP2D6 genotyping.

Conditions

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Late Onset Alzheimer Disease

Keywords

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Alzheimer APOE CYP2D6 Donepezil Genetics

Study Design

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Observational Model Type

OTHER

Study Time Perspective

PROSPECTIVE

Eligibility Criteria

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Inclusion Criteria

* Patients fulfilling the National Institute on Aging and the Alzheimer's Association diagnostic criteria of probable AD dementia or the NINDS-AIREN (National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherché et l'Enseignement en Neurosciences) diagnostic criteria of AD with cerebrovascular disease (AD + CVD)
* Patients presenting mild or moderate dementia according to the Clinical Dementia Rating (CDR), i.e., CDR 1 or 2, respectively

Exclusion Criteria

* Patients treated with ChEI or memantine before study entry
* Patients diagnosed with frontotemporal dementia, dementia with Lewy bodies or vascular dementia,
* Patients classified as CDR 3 or with Mild Cognitive Impairment
* Illiterate patients
* Disagreement between the first investigator and the treating physician regarding the diagnosis

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Responsible Party

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Luís Felipe José Ravic de Miranda

Physician, Geriatrician, MD, PhD

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Paulo Caramelli, MD, PhD

Role: STUDY_CHAIR

Federal University of Minas Gerais

Other Identifiers

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0172 /2010

Identifier Type: -

Identifier Source: org_study_id