Identification of potential clinically significant drug interactions in HIV‐infected patients: a comprehensive therapeutic approach

Abstract

ObjectivesThe aim of the study was to determine the prevalence of potential clinically significant drug interactions (CSDIs) in HIV-positive individuals and to identify associated risk factors. MethodsA cross-sectional study was conducted including all HIV-infected out-patients attending the Pharmacy Service of a regional reference hospital in Murcia, south-eastern Spain. The complete treatment was screened for possible CSDIs using the Spanish College of Pharmacists' online software resource, BOT. Additionally, the severity level of the CSDIs involving antiretroviral (ARV) drugs was compared with that established in the specific antiretroviral database InteraccionesHIV.com. Multivariate logistic regression was used to identify associated risk factors. ResultsTwo hundred and sixty-eight patients were included in the study. A total of 292 potential drug interactions were identified, of which 102 (34.9%) were CSDIs, of which 52.9% involved ARV drugs. Seven therapeutic drug classes were involved in 75% of CSDIs (protease inhibitors, benzodiazepines, nonsteroidal anti-inflammatory drugs, nonnucleoside reverse transcriptase inhibitors, corticosteroids, antithrombotics and proton pump inhibitors). Factors independently associated with CSDIs were treatment with more than five drugs [odds ratio (OR) 15.1; 95% confidence interval (CI) 6.3-36.2], and treatment with a protease inhibitor (OR 5.3; 95% CI 2.4-11.74). ConclusionsThe findings of this study suggest that the prevalence of clinically relevant drug−drug interactions is high in HIV-infected patients, and could represent a major health problem. Awareness, recognition and management of drug interactions are important in optimizing the pharmaceutical care of HIV-infected patients and helping to prevent adverse events and/or loss of efficacy of the drugs administered.Keywords: antiretroviral therapy, drug interactions, HIV, outpatient, risk factors Accepted 4 September 2014 IntroductionAs a result of improved antiretroviral therapy (ART), the expected lifespan of HIV-positive individuals has increased dramatically, but comorbidities such as cardiovascular disease, hyperlipidaemia, hypertension, diabetes, osteoporosis, renal disease and non-AIDS-related cancers are increasingly common [1]. Because of this comorbidity, a wide variety of drugs (e.g. antidepressives or antibacterials) are used alongside antiretroviral drugs. However, the combination of such drugs presents the potential for drug-drug interactions (DDIs), an important cause of adverse drug reactions (ADRs). . Several studies have suggested a positive correlation between increased age and increased risk for drug interactions in HIV-positive patients [5]. However, most studies focus on interactions involving at least one antiretroviral (ARV) drug and ignore those that involve non-ARV drugs, despite the fact that such drugs may be responsible for undesirable side effects, which may reduce adherence to treatment with a consequent decrease in effectiveness.The recognition and management of drug interactions are imp...

A Pharmacist‐Led Program to Evaluate and Reduce Polypharmacy and Potentially Inappropriate Prescribing in Older HIV‐Positive Patients

“…Although drug‐drug interactions (DDIs) are well described in patients living with HIV, the prevalence, nature, and consequences of polypharmacy are less well described . In addition, potentially inappropriate prescribing (PIP), associated with polypharmacy, is poorly studied in HIV‐infected individuals, although it is better described in the general population.…”

“…15,16 Although drug-drug interactions (DDIs) are well described in patients living with HIV, the prevalence, nature, and consequences of polypharmacy are less well described. [17][18][19][20] In addition, potentially inappropriate prescribing (PIP), associated with polypharmacy, is poorly studied in HIV-infected individuals, although it is better described in the general population. The updated Beers Criteria (named after geriatrician Mark H. Beers, who created the criteria in 1991 to improve the safety of prescribing medications in older adults) and the Screening Tool of Older Persons' Potentially Inappropriate Prescriptions (STOPP) criteria are two validated instruments used to assess PIP in older patients.…”

Ageing with HIV: do comorbidities and polymedication drive treatment optimization?

“…Polypharmacy is of growing interest in patients ageing with HIV infection . In another prospective European cohort , the same proportion of patients receiving comedications was described, highlighting the ongoing potential for serious DDIs in HIV practice as a result of polypharmacy.…”

“…It is of growing importance for HIV physicians to limit the use of these drugs and to provide counselling for healthy ageing, with particular attention to patients ageing with a long HIV history, as they represent a distinct group from those who have seroconverted while ageing [3]. Polypharmacy is of growing interest in patients ageing with HIV infection [6,7,[19][20][21]. In another prospective European cohort [22], the same proportion of patients receiving comedications was described, highlighting the ongoing potential for serious DDIs in HIV practice as a result of polypharmacy.…”

“…However, the combination of these drugs produces a high potential for drugÀdrug interactions (DDIs) that may result in either loss of efficacy or increased toxicity of the respective drugs. In a recent Spanish study, 292 potential DDIs were found in 268 patients, mainly involving boosted protease inhibitors (bPIs), benzodiazepines, nonsteroidal anti-inflammatory drugs, nonnucleoside reverse transcriptase inhibitors (NNRTIs), corticosteroids, proton pump inhibitors and antithrombotics [6]. In the same study, it was found that clinically significant interactions were strongly related to the use of ritonavirboosted PIs because of the mixed inducer/inhibitor effects of ritonavir on different cytochrome P450 pathways [7].…”