CP-090 Clinical relevance of drug interactions detected in hepatitis C (Genotype 1) triple therapy patients

Abstract

Background Protease inhibitors (PIs), i.e. boceprevir (BOC) and telaprevir (TLV), are metabolised by CYP3A and they are CYP3A inhibitors. This predisposes them to many drug interactions. The identification and management of potential drug interactions with PIs is necessary to optimise the treatment in Hepatitis C (HC) patients. Purpose To describe drug interactions and clinical management in HC (genotype 1) patients, at the beginning and during triple therapy. Material and methods Descriptive study involving recording the patient’s initial treatment using PI and the addition of new drugs throughout the treatment. A drug-interaction analysis of the different PI-based treatments was conducted. Interactions were classified into four categories: Category 1: No clinically significant interaction; Category 2: possible interaction but manageable with dose adjustment or monitoring; Category 3: Co-administration is not recommended; Category 4: no classification due to lack of data. Results A total of 47 patients was treated (8 with BOC and 39 with TLV), 32 (68%) men, average age of 54 ± 8.5 years, 25 (53%) with advanced fibrosis and 33 (70%) previously treated. A total of 211 drugs prescribed together with triple therapy were studied. Average number of drugs was 4.49 ± 2.61, only 3 (6%) patients did not need a drug interactions study. According to the classification, there were 102 (55%) category 1, 72 (34%) category 2, 9 (5%) category 3 and 13 (6%) category 4 drug interactions. Regarding clinical management of interactions: none of the drugs included in categories 1 and 2 was suspended, while 8 (89%) from category 3 and 2 (15%) from category 4 were (in this last case due to lack of data, always with medical-pharmaceutical consensus). Conclusion The study reveals a high number of drug interactions when PIs are used as well as HC treatment, but only a low number of these interactions required drug suspension. Categorising the drug interactions aids both clinical management and doctors’ decision-making. References and/or Acknowledgements http://www.hep-druginteractions.org/ http://www.micromedexsolutions.com/ No conflict of interest.