Bleeding associated with self-medication in warfarin users

A prospective observational study in Ijuí (Brazil)

Authors

  • Isabela Heineck Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil https://orcid.org/0000-0002-8448-5994
  • Albert Figueras Fundació Institut Català de Farmacologia, Departament de Farmacologia, Terapèutica i Toxicologia, Universitat Autònoma de Barcelona, UAB, Spain https://orcid.org/0000-0002-2740-2013
  • Stela Maris Jesus Castro Departamento de Estatística, Instituto de Matemática e Estatística, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil
  • Tânia Alves Amador Programa de Pós-Graduação em Assistência Farmacêutica, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil
  • Christiane de Fátima Colet Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, UFRGS, Brazil https://orcid.org/0000-0003-2023-5088

DOI:

https://doi.org/10.1590/s2175-97902022e20959

Keywords:

Bleeding, self-medication, Warfarin, Adverse effects, primary care, Brazil

Abstract

Warfarin has been associated with bleeding and venous thromboembolism. Objective: This study aimed to estimate the association between bleeding and concomitant self-medication, and the incidence of adverse drug reactions in patients using warfarin. Setting: the public health network of Ijuí, a municipality in southern Brazil. This was an open prospective cohort, conducted for a period of 18 months with users of warfarin, treated at the public health service. The association between bleeding and self-medication was evaluated by means of the Cox Model with left truncation, using the time variable. Main outcome measurement: bleeding reported in the follow-up. Cases of thromboembolism and death were also registered. All patients treated with warfarin in the public health system of the municipality (98) were identified. Sixty-eight were interviewed and followed up, of whom 63 completed follow-up and five died during the study. Bleeding rates of 37.7 /100 patients/year, thromboembolism of 4.8/100 patients / year and deaths of 4.8 /100 patients / year were observed. The results showed that patients, who take warfarin and self-medicated present a two-fold increased bleeding, compared with those who do not self-medicate. The bleeding risk associated with self-medication ranged from 2.001 to 2.685; those values maintained their significance even when adjusted for number of interactions, CYP polymorphism, TTR and age in COX analysis. These results greatly suggest the need for providing greater assistance to patients who take anticoagulant medications with the purpose of reducing self-medication and consequently, adverse reactions.

Downloads

Download data is not yet available.

References

Awad AI, Eltayeb IB, Capps PA. Self-medication practices in Khartoum State, Sudan. Eur J Clin Pharmacol. 2006;62(4):317-24.

Ayalew MB. Self-medication practice in Ethiopia: a systematic review. Patient Prefer Adherence. 2017;1(11):401-413.

Benhamou Y, Le Cam-Duchez V, Schneller JM, Cailleux N, Magne JC, Soubrane JC, et al. Expérience d’un centre de suivi et de conseil des traitements anticoagulants oraux en médecine de ville: résultats à cinq ans: Anticoagulation clinics for outpatients: A 5-year experience. Rev Med Interne. 2009;30(7):567-572.

Carrasco-Garrido P, Hernández-Barrera V, López de Andrés A, Jiménez-Trujillo I, Jiménez-García R. Sex differences on self-medication in Spain. Pharmacoepidemiol Drug Saf. 2010;19(12):1293-9.

Castro TA, Heineck I. Interventionstoimproveanticoagulation with warfarin. Ther Drug Monit. 2012;34(2):209-216.

CHA2DS2-VASc Score for Atrial Fibrillations Stroke Risk. [Internet]. 2016. Available: http://www.mdcalc.com/cha2ds2-vasc-score-for-atrial-fibrillation-stroke-risk/

» http://www.mdcalc.com/cha2ds2-vasc-score-for-atrial-fibrillation-stroke-risk/

Cressman AM, Macdonald EM, Yao Z, Austin PC, Gomes T, MHS, et al. Socioeconomic status and risk of hemorrhage during warfarin therapy for atrial fibrillation: A population-based study. Am Heart J. 2015;170(1):133-40.

Deitelzweig SB, Pinsky B, Buysman E, Lacey M, Makenbaeva D, Wiederkehr D, et al. Bleeding as an outcome among patients with nonvalvular atrial fibrillation in a large managed care population. Clin Ther. 2013;35(10):1536-45.

Domingues PHF, Galvão TF, Andrade KRC, Sá PTT, Silva MT, Pereira MG. Prevalência da automedicação na população adulta do Brasil: revisão sistemática. Rev Saúde Púb. 2015;49(36).

Esmerio FG, Souza EN, Leiria TL, Lunelli R, Moraes MA. Uso crônico de anticoagulante oral: implicações para o controle de níveis adequados. Arq Bras Cardiol. 2009;93(5):508-512.

Eticha T, Mesfin K. Self-medication practices in Mekelle, Ethiopia. PloS One. 2014;9(5):e97464.

Gavillán-Moral, Villafaina-Barroso A, Jiménez-de Garcia L, Gómez Santana C. Ancianos frágiles polimedicados: ¿es la deprescripción de medicamentos una salida? Rev Esp Geriatr Gerontol. [Internet]. 2012. Available: http://www. sciencedirect.com/science/article/pii/S0211139X12000601

» http://www. sciencedirect.com/science/article/pii/S0211139X12000601

Hallinen T, Soini EJ, Asseburg C, Kousmanen P, Kaakkonen A. Warfarin treatment among Finnish patients with atrial fibrillation: retrospective registry study based on primary healthcare data. BMJ Open. 2014;4:e004071.

Ghousain HEE, Thomas M, Vaghese SJ, Hegazi MO, Kumar R. Long term oral anticoagulant therapy with warfarin: experience with local patient population in Kuwait Indian. J Hematol Blood Transfus. 2014;30(2):111-9.

Jain S, Prerna U, Jaswant G, Abhijit K, Pushpawati J, Vikas S, et al. A systematic review of prescription pattern monitoring studies and their effectiveness in promoting rational use of medicines. Perspect Clin Res. 2015;6(2):86-90.

Jorgensen AL, FitzGerald RJ, Oyee J, Pirmohamed M, Williamson PR. Influence of CYP2C9 and VKORC1 on patient response to warfarin: a systematic review and meta-analysis. PLoS One. 2012;7(8):e44064.

Jover E Roldán V, Gallego P, Hernández-Romero D, Valdés M, Vicente V, Lip GY, et al. Predictive value of the CHA2DS2-VASc score in atrial fibrillation patients at high risk for stroke despite oral anticoagulation. Rev Esp Cardiol. 2012; 65(7):627-33.

Jun M, Lix LM, Durand M, Dahl M, Paterson JM, Dormuth CR, et al. Comparative safety of direct oral anticoagulants and warfarin in venous thromboembolism: multicentre, population based, observational study. BMJ. 2017;359:j4323.

Kimmel SE, Chen Z, Price M, Parker CS, Metlay JP, Christie JD, et al. The influence of patient adherence on anticoagulation control with warfarin results from the international normalized ratio adherence and genetics (IN-RANGE) Study. Arch Intern Med. 2007;167:229-35.

Klemenc-Ketis Z, Mitrovic D. Patients› use of and attitudes towards self-medication in rural and remote Slovenian family medicine practices: a cross-sectional multicentre study. Rural Remote Health. 2017;17(2):3893.

Kotirum S, Chaiyakunapruk N, Jampachaisri K, Wattanasombat S, Rojnuckarin P. Utilization review of concomitant use of potentially interacting drugs in Thai Patients using warfarin therapy. Pharmacoepidemiol Drug Saf . 2007;16(2):216-22.

Labaf A, Grzmala-Lubanski B, Stagmo M, Lovdahl S, Sjalander S. Thromboembolism, major bleeding and mortality in patients with mechanical heart valves- a population-based cohort study. Thromb Res. 2014;134(2):354-359.

Lee T, Davis E, Kielly J. Clinical impact of a pharmacist-led inpatient anticoagulation service: a review on the literature. Integr Pharm Res Pract. 2016;5:53-63.

Leiria TL, Pellanda L, Miglioranza MH, Sant’Anna RT, Becker LS, Magalhães E, et al. Warfarin and phenprocoumon: experience of an outpatient anticoagulation clinic. Arq Brasil Cardiol. 2010;94(1):41-5.

Merli GJ, Hollander JE, Lefebvre P, Laliberté F, Raut MK, Germain G, et al. Costs of hospital visits among patients with deep vein thrombosis treated with rivaroxaban and LMWH/warfarin. J Med Econ. 2016;19(1):84-90.

Micromedex® Healthcare Series. [Internet]. Greenwood Village, Colo: Thomson Healthcare. [acessed: 2018 mar 29]. Available: Available: http://www-micromedexsolutions-com.ez115.periodicos.capes.gov.br/micromedex2/librarian

» http://www-micromedexsolutions-com.ez115.periodicos.capes.gov.br/micromedex2/librarian

Palareti G, Leali N, Coccheri S, Poggi M, Manotti C, D`Angelo A, et al. Bleeding complications of oral anticoagulant treatment: an inception-cohort, prospective collaborative study (ISCOAT). Italian Study on Complications of Oral Anticoagulant Therapy. Lancet. 1996;348(9025):423-8.

Pastori D, Pignatelli P, Saliola M, Carnevale R, Vicario T, Del Ben M, et al. Inadequate anticoagulation by vitamin K antagonista is associated with major adverse cardiovascular events in patientes with atrial fibrilation. Int J Cardiol. 2015;201:513-6.

Schimidt L, Spechman J, Ansell J. Quality Assessment of Anticoagulation Dose Management: Comparative Evatuation o Measures of Time-in-Therapeutic Range. J Thromb Thrombolysis. 2003;15(3):213-6.

Suh DC, Choi JC, Schein J, Kim S, Nelson WW. Factors associated with warfarin discontinuation, including bleeding patterns, in atrial fibrillation patients. Curr Med Res Opin. 2013;29(7):761-71.

Suleman S, Ketsela A, Mekonnen Z. Assessment of self-medication practices in Assendabo town, Jimma zone, southwestern Ethiopia. Res Social Adm Pharm. 2009;5(1):76-81.

Teklay G, Shiferaw N, Legesse B, Bekele ML. Drug-drug interactions and risk of bleeding among inpatients on warfarin therapy: a prospective observational study. Thromb J. 2014;12:20.

Zamir Q, Nadeem A. Non-steroidal anti-inflammatory drugs vs. Paracetamol: drug availability, patients› preference and knowledge of toxicity. J Ayub Med Coll Abbottabad. 2016;28(4):746-749.

Downloads

Published

2023-02-07

Issue

Section

Original Article

How to Cite

Bleeding associated with self-medication in warfarin users: A prospective observational study in Ijuí (Brazil). (2023). Brazilian Journal of Pharmaceutical Sciences, 58. https://doi.org/10.1590/s2175-97902022e20959