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Coin A, Pamio MV, Alexopoulos C, Granziera S, Groppa F, de Rosa G, Girardi A, Sergi G, Manzato E, Padrini R. Donepezil plasma concentrations, CYP2D6 and CYP3A4 phenotypes, and cognitive outcome in Alzheimer's disease. Eur J Clin Pharmacol 2016; 72:711-7. [PMID: 26952092 DOI: 10.1007/s00228-016-2033-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/24/2016] [Indexed: 01/17/2023]
Abstract
PURPOSE The purpose of the study is to evaluate whether donepezil (D) plasma concentrations and activity of CYP2D6 and CYP3A4 are associated with the therapeutic response of patients with mild to moderate Alzheimer's disease (AD). METHODS This study comprised 54 patients affected by probable AD in therapy with D 10 mg/daily for at least 3 months. Plasma concentrations of D and its three main metabolites (6DD, 5DD, DNox) were assayed with a novel high performance liquid chromatography (HPLC) technique. Cognitive progression was assessed at baseline and at 9 months of follow-up with the mini mental state examination (MMSE). The activities of the two cytochromes involved in D metabolism-CYP2D6 and CYP3A4-were evaluated according to their metabolic ratios in plasma or urine, after test doses of probe drugs (dextromethorphan and omeprazole). RESULTS A significant correlation was found between plasma levels of D and variations in MMSE scores after 9 months of therapy (r (2) = 0.14; p = 0.006). Neither the concentrations of D metabolites nor the metabolic ratios of CYP2D6 and CYP3A4 showed any correlations with cognitive variations. Low CYP2D6 activity and advanced age were associated with high D concentrations. Patients who were treated with CYP2D6 and P-glycoprotein (P-gp) inhibitors also had higher D plasma levels (mean difference = 19.6 ng/mL; p = 0.01) than those who were not. CONCLUSIONS D plasma concentrations, but not cytochrome phenotyping, are associated with cognitive outcomes in AD patients.
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Affiliation(s)
- A Coin
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - M V Pamio
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - C Alexopoulos
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - S Granziera
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - F Groppa
- Clinical Pharmacology Unit, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - G de Rosa
- Clinical Pharmacology Unit, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - A Girardi
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - G Sergi
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - E Manzato
- Geriatric Clinic, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy
| | - R Padrini
- Clinical Pharmacology Unit, Department of Medicine DIMED, School of Medicine, University of Padova, 35128, Padova, Italy.
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