Warfarin drug interactions: a comparative evaluation of the lists provided by five information sources

Martins, Marcos A. P.; Carlos, Paula P. S.; Ribeiro, Daniel Dias; Nobre, Vandack; César, Cibele Comini; Rocha, Manoel Otávio Costa; Ribeiro, Antônio Luiz Pinho

doi:10.1007/s00228-011-1086-4

Cited by 38 publications

(40 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…9 The difference in the total number of possible DDIs did not cause this discordance between most of the various DDI programs and it was suggested that this could be caused because of differences in the severity classification in these programs. [10][11][12][13] The concordance between the DDI programs used in the present study was high in terms of the number of patients detected with possible DDI in each program when compared with previous studies mentioned above. Although the DDI programs used in the present study were quite similar to each other according to the severity classification of possible DDIs, the concordances regarding the rate of severity ranking were low.…”

Section: Discussionsupporting

confidence: 52%

Determination of Potential Drug–Drug Interactions Using Various Software Programs in a Community Pharmacy Setting

Sancar¹,

Kaşik²,

Okuyan³

et al. 2019

tjps

View full text Add to dashboard Cite

ÖZAmaç: Çalışmada eczaneye gelen reçetelerdeki olası ilaç-ilaç etkileşimlerinin saptanması ve farklı yazılım programları kullanılarak belirlenen olası ilaç-ilaç etkileşim sonuçlarının karşılaştırılması amaçlanmıştır. Gereç ve Yöntemler: Çalışma Mart ile Nisan 2015 (haftada iki gün) tarihleri arasında İstanbul'da yer alan 50 eczanede yürütülmüştür. Çalışmanın yürütüleceği eczanelerde en az 2 ilaç bulunan ardışık 20 reçetedeki olası ilaç-ilaç etkileşmeleri incelenmiştir. Olası ilaç-ilaç etkileşimleri micromedexsolutions.com, medscape.com ve drugs.com programları kullanılarak karşılaştırılmıştır. Bulgular: Çalışmamızda toplam 1000 elektronik reçete incelenmiş ve bu reçetelerin %39.2'sinde yazılım programların herhangi birine göre en az bir tane olası ilaç-ilaç etkileşimi tespit edilmiştir. Reçetelerde saptanan olası ilaç-ilaç etkileşimlerinin yazılımlar tarafından bulunma oranları, 'micromedexsolutions.com' için %21.2, 'medscape.com' için %33.3 ve 'drugs.com' için ise %31.3 olarak hesaplanmıştır. Sonuç: Farklı yazılım programlarını karşılaştırdıktan sonra, yazılım programları tarafından bulunan potansiyel ilaç-ilaç etkileşimlerinin birbirlerinden farklı olduklarını kanıtlanmıştır. Bu nedenle, eczacıların, klinik olarak anlamlı ilaç-ilaç etkileşimi saptadıklarında, karar vermeden önce bu etkileşimleri farklı bir programla da teyit etmelerini önermekteyiz. Anahtar kelimeler: İlaç-ilaç etkileşimleri, yazılım programları, serbest eczane, eczacı Objectives:The aim of the present study was to compare various software programs in detecting potential drug-drug interactions in a community pharmacy setting. Materials and Methods: Details of prescriptions were collected from 50 community pharmacies located in İstanbul in March and April 2015 (two days per week). From each pharmacy, the first 20 prescriptions that included more than one drug were collected to evaluate potential drug-drug interactions. The following software programs were utilized to detect potential drug-drug interactions: micromedexsolutions.com, medscape.com, and drugs.com. The number of potential interactions detected by the software programs was determined. Results: At least one potential drug-drug interaction was detected in 39.2% of the 1000 prescriptions by one of the software programs. According to the rates of total drug-drug interactions gathered from various software programs, these programs gave the following results: medscape.com 33.3%, drugs.com 31.3%, and micromedexsolutions.com 21.2%. Conclusion: After comparing different software programs, the potential drug-drug interactions found by the programs proved to be different. Therefore, we recommend that pharmacists confirm with a different program before making a decision when they detect clinically significant potential drug-drug interactions.

show abstract

Section: Discussionsupporting

confidence: 52%

Determination of Potential Drug–Drug Interactions Using Various Software Programs in a Community Pharmacy Setting

Sancar¹,

Kaşik²,

Okuyan³

et al. 2019

tjps

View full text Add to dashboard Cite

show abstract

“…Racemic warfarin accumulates in the liver, in which both the R and the S enantiomers are metabolically transformed by different pathways [10]. The S enantiomer is approximately 90% oxidatively metabolized, primarily by the CYP2C9 enzyme of the CYP system and, to a lesser extent, by CYP3A4.…”

Section: Introductionmentioning

confidence: 99%

Rifampicin-warfarin interaction leading to macroscopic hematuria: a case report and review of the literature

Martins

Reis

Sales

et al. 2013

BMC Pharmacol Toxicol

View full text Add to dashboard Cite

BackgroundRifampicin remains one of the first-line drugs used in tuberculosis therapy. This drug´s potential to induce the hepatic cytochrome P450 oxidative enzyme system increases the risk of drug-drug interactions. Thus, although the presence of comorbidities typically necessitates the use of multiple drugs, the co-administration of rifampicin and warfarin may lead to adverse drug events. We report a bleeding episode after termination of the co-administration of rifampicin and warfarin and detail the challenges related to international normalized ratio (INR) monitoring.Case presentationA 59-year-old Brazilian woman chronically treated with warfarin for atrial fibrillation (therapeutic INR range: 2.0-3.0) was referred to a multidisciplinary anticoagulation clinic at a university hospital. She showed anticoagulation resistance at the beginning of rifampicin therapy, as demonstrated by repeated subtherapeutic INR values. Three months of sequential increases in the warfarin dosage were necessary to reach a therapeutic INR, and frequent visits to the anticoagulation clinic were needed to educate the patient about her pharmacotherapy and to perform the warfarin dosage adjustments. The warfarin dosage also had to be doubled at the beginning of rifampicin therapy. However, four weeks after rifampicin discontinuation, an excessively high INR was observed (7.22), with three-day macroscopic hematuria and the need for an immediate reduction in the warfarin dosage. A therapeutic and stable INR was eventually attained at 50% of the warfarin dosage used by the patient during tuberculosis therapy.ConclusionsThe present case exemplifies the influence of rifampicin therapy on warfarin dosage requirements and the increased risk of bleeding after rifampicin discontinuation. Additionally, this case highlights the need for warfarin weekly monitoring after stopping rifampicin until the maintenance dose of warfarin has decreased to the amount administered before rifampicin use. In particular, patients with cardiovascular diseases and active tuberculosis represent a group with a substantial risk of drug-drug interactions. Learning how to predict and monitor drug-drug interactions may help reduce the incidence of clinically significant adverse drug events.

show abstract

“…One of the most important causes of variability in warfarin response and fluctuating INR values is warfarin–drug interactions . Various drugs have been reported to interact with warfarin, which consequently represents a challenge to health care professionals to adjust and maintain the warfarin therapeutic response . The mechanism of interaction of these drugs with warfarin is either pharmacokinetic interaction by altering absorption, distribution, metabolism, and excretion of warfarin or by pharmacodynamic interaction by concomitantly prescribing drugs that cause additional impairment of coagulation .…”

mentioning

confidence: 99%

“…Other proposed mechanisms of interaction include alteration of absorption of warfarin by other drugs (eg, cholestyramine), disruption of vitamin K synthesizing gut flora (eg, broad‐spectrum antibiotics), displacement from plasma protein‐binding sites, and augmentation of anticoagulation by inhibiting platelet function (eg, aspirin and other antiplatelets) . There is a wide variability among information resources regarding warfarin–drug interactions . Warfarin–drug interactions reporting in the literature is often conflicting and generally poor in quality .…”

mentioning

confidence: 99%

Warfarin-drug interactions: An emphasis on influence of polypharmacy and high doses of amoxicillin/clavulanate

Abdel‐Aziz

Ali

Abolghasemi

et al. 2015

The Journal of Clinical Pharmacology

View full text Add to dashboard Cite

The objective of this study was to investigate the effect of polypharmacy and high doses of amoxicillin/clavulanate on warfarin response in hospitalized patients. This was a prospective cross-sectional observational study on 120 patients from July 2013 to January 2014. Potentially interacting drugs were classified according to their tendency of increasing international normalized ratio (INR) or bleeding risk. The 87.5% of patients prescribed high-dose amoxicillin/clavulanate (10-12 g daily) compared with 28.9% of patients prescribed a normal dose (up to 3.6 g daily) had INR values ≥ 4 during the hospital stay (P ≤ .001). Increased number of potentially interacting drugs that are known to increase INR was a significant predictor of having INR values ≥ 4 (OR, 2.5; 95%CI, 1.3-4.7), and increased number of potentially interacting drugs that are known to increase bleeding risk was a significant predictor of experiencing bleeding episodes (OR, 3.1; 95%CI, 1.3-7.3). High doses of amoxicillin/clavulanate were associated with a higher risk of over-anticoagulation when combined with warfarin than were normal doses. Increased risk of having INR ≥ 4 and bleeding events was associated with increased numbers of potentially interacting drugs prescribed, indicating that polypharmacy is a problem of concern. Frequent monitoring of warfarin therapy along with patients' medications is necessary to avoid complications.

show abstract

Warfarin drug interactions: a comparative evaluation of the lists provided by five information sources

Cited by 38 publications

References 35 publications

Determination of Potential Drug–Drug Interactions Using Various Software Programs in a Community Pharmacy Setting

Determination of Potential Drug–Drug Interactions Using Various Software Programs in a Community Pharmacy Setting

Rifampicin-warfarin interaction leading to macroscopic hematuria: a case report and review of the literature

Warfarin-drug interactions: An emphasis on influence of polypharmacy and high doses of amoxicillin/clavulanate

Contact Info

Product

Resources

About