Prevalence and Predictors of Potential Drug-Drug Interactions in the Elderly: A Cross-Sectional Study in the Brazilian Primary Public Health System

Authors

  • Paulo Roque Obreli Neto Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, PR, Brazil
  • Alessandro Nobili Laboratory of Quality Assessment of Geriatric Therapies and Services, and Drug Information Services for the Elderly, Istituto di Ricerche Farmacologiche, Milano, Italy.
  • Srecko Marusic Department of Clinical Pharmacology, University Hospital Dubrava, Zagreb, Croatia.
  • Diogo Pilger Department of Medicines, Federal University of Bahia, Salvador, BA, Brazil.
  • Camilo Molino Guidoni Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil.
  • André de Oliveira Baldoni Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil.
  • Joice Mara Cruciol-Souza Department of Pharmaceutical Sciences, State University of Londrina, Londrina, PR, Brazil.
  • Alessandra Negri da Cruz Department of Pharmacy, Faculdades Integradas de Ourinhos, Ourinhos, SP, Brazil.
  • Walderez Penteado Gaeti Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, PR, Brazil.
  • Roberto Kenji Nakamura Cuman Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, PR, Brazil.

DOI:

https://doi.org/10.18433/J37K5W

Abstract

Purpose. The primary objective of this study was to investigate the prevalence of clinically important potential drug-drug interactions (DDIs) in elderly patients attending the public primary health care system in Brazil. The secondary objective was to investigate possible predictors of potential DDIs. Methods. A cross-sectional study was carried out in 5 Brazilian cities located in the Ourinhos Micro-region, Sao Paulo State, between November 2010 and April 2011. The selected sample was divided according to the presence (exposed) or absence (unexposed) of one or more potential DDIs (defined as the presence of a minimum 5-day overlap in supply of an interacting drug pair). Data were collected from medical prescriptions and patients’ medical records. Potential DDIs (rated major or moderate) were identified using 4 DDI-checker programs. Logistic regression analysis was used to study potential DDI predictors. Results. The prevalence of clinically important potential DDIs found during the study period was 47.4%. Female sex (OR = 2.49 [95% CI 2.29–2.75]), diagnosis of ≥ 3 diseases (OR = 6.43 [95% CI 3.25–12.44]), and diagnosis of hypertension (OR = 1.68 [95% CI 1.23–2.41]) were associated with potential DDIs. The adjusted OR increased from 0.90 [95% CI 0.82–1.03] in patients aged 60 – 64 years to 4.03 [95% CI 3.79 – 4.28] in those aged 75 years or older. Drug therapy regimens involving ≥ 2 prescribers (OR = 1.39 [95% CI 1.17–1.67]), ≥ 3 drugs (OR = 3.21 [95% CI 2.78–3.59]), ≥ 2 ATC codes (OR = 1.19 [95% CI 1.12–1.29]), ≥ 2 drugs acting on cytochrome P450 (OR = 2.24 [95% CI 2.07–2.46]), and ATC codes B (OR = 1.89 [95% CI 1.05–2.08]) and C (OR = 4.01 [95% CI 3.55–4.57]) were associated with potential DDIs. Conclusion. Special care should be taken with the prescription and therapeutic follow-up of patients who present characteristics identified as predictors. Knowledge of potential DDI predictors could aid in developing preventive practices and policies that allow public health services to better manage this situation. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

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Author Biographies

Paulo Roque Obreli Neto, Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, PR, Brazil

Department of Pharmacology and Therapeutics

Alessandro Nobili, Laboratory of Quality Assessment of Geriatric Therapies and Services, and Drug Information Services for the Elderly, Istituto di Ricerche Farmacologiche, Milano, Italy.

2Laboratory of Quality Assessment of Geriatric Therapies and Services, and Drug Information Services for the Elderly

Srecko Marusic, Department of Clinical Pharmacology, University Hospital Dubrava, Zagreb, Croatia.

Department of Clinical Pharmacology

Diogo Pilger, Department of Medicines, Federal University of Bahia, Salvador, BA, Brazil.

Department of Medicines

Camilo Molino Guidoni, Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil.

Department of Pharmaceutical Sciences

André de Oliveira Baldoni, Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil.

Department of Pharmaceutical Sciences

Joice Mara Cruciol-Souza, Department of Pharmaceutical Sciences, State University of Londrina, Londrina, PR, Brazil.

Department of Pharmaceutical Sciences

Alessandra Negri da Cruz, Department of Pharmacy, Faculdades Integradas de Ourinhos, Ourinhos, SP, Brazil.

Department of Pharmacy

Walderez Penteado Gaeti, Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, PR, Brazil.

Department of Pharmacology and Therapeutics

Roberto Kenji Nakamura Cuman, Department of Pharmacology and Therapeutics, State University of Maringá, Maringá, PR, Brazil.

Department of Pharmacology and Therapeutics

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Published

2012-05-04

How to Cite

Obreli Neto, P. R., Nobili, A., Marusic, S., Pilger, D., Guidoni, C. M., Baldoni, A. de O., … Cuman, R. K. N. (2012). Prevalence and Predictors of Potential Drug-Drug Interactions in the Elderly: A Cross-Sectional Study in the Brazilian Primary Public Health System. Journal of Pharmacy & Pharmaceutical Sciences, 15(2), 344–354. https://doi.org/10.18433/J37K5W

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Section

Pharmacy Practice, Education & Socioeconomy