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ID Week 2103: Polypharmacy in HIV
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Report written for NATAP by David H. Shepp, MD Associate Professor of Medicine Hofstra North Shore-LIJ School of Medicine North Shore University Hospital - Manhasset, NY
A major focus of antiretroviral research has been simplification of antiretroviral (ARV) therapy. Many low-pill burden, once daily regimens are now available, improving adherence and making treatment-success achievable for many more patients. However, as HIV patients live-longer, they may develop chronic diseases of aging, many of which occur with increased frequency compared to the general population. Treatment of these illnesses complicates care by increasing pill burden, creating drug-drug interactions and may jeopardizes the gains achieved by ARV therapy simplification. Two abstracts presented at ID Week 2013 compared polypharmacy, defined as prescription of >5 non-ARV meds, in HIV-infected patients and matched HIV-negative controls. Using data from a large private health claims database, Koram et al. found more comorbid diagnoses and greater use of each of 8 classes of commonly prescribed medications over a one year observation period in both younger (age 18-49) and older (age ≥50) HIV-infected patients [1]. More than 5 non-ARV medications were prescribed for 54% and 34% of older HIV-infected and uninfected patients, respectively, while corresponding numbers for the younger group were 35% and 19%. Edelman et al. quantified medication use over a one year period in the large Veterans Aging Cohort Study database [2]. They found high rates of comorbidities and medication use in both HIV-infected patients and matched HIV-negative controls, but reported slightly higher rates among the HIV-negative veterans. An analysis of subsequent mortality adjusted for gender, race/ethnicity and VACS index score showed an increasing hazard of death in those prescribed 3 or more medications, reaching about 2-fold for HIV-infected patients prescribed 5 or more medications and uninfected patients prescribed 8 or more medications.
Both studies show there is a large amount of polypharmacy in HIV-infected patients. The contrasting findings for the matched controls probably can be explained by higher rates of comorbid illness in the general VA care population relative to HIV-uninfected individuals with private health insurance. The association of polypharmacy with increased mortality is concerning but the cause is unclear. Most likely, greater mortality is simply due to more severe underlying comorbid illnesses. However, it is possible that patients receiving polypharmacy have more toxicity and/or lower treatment efficacy resulting from drug-drug interactions or reduced adherence. Further studies of polypharmacy and mortality may provide better understanding of the relationship.
Polypharmacy with ARV and non-ARV medication may lead to reduced adherence. HIV clinicians are well aware of the importance of consistent, high levels of adherence because periods of lower adherence not only affect current efficacy, but may permit evolution of viral resistance, leading to persistent treatment failure even if adherence subsequently improves. Levels of adherence to other medications may receive less attention, in part because periods of low adherence do not generally cause treatment resistance. To determine if there is differential adherence to ARV and non-ARV medications, Kodama et al. examined pharmacy refill records at a large VA Medical Center [3]. One-hundred seventy-one HIV-infected individuals prescribed both types of medication over a one year period were included in the analysis. Adherence was expressed as the proportion of days covered (PDC), meaning medication was in the patient's possession based on date of refill. Only chronic medications were analyzed; short-term prescriptions and "prn" usage were not included. The PDC for ARVs was 88% and for non-ARVs 77%, a significant difference (p<0.001). In this study, age, copayment requirement, depression, and substance abuse did not correlate with lower adherence. Interestingly, PDC varied by medication category. PDC for antihypertensives was in the 85-90% range. The lower adherence for non-ARV medications appeared to driven by lower rates of adherence for vitamins, acid-reducing agents and anti-depressants. More research is needed to fully understand the reasons for better adherence to certain types of medication than others. However, these results suggest the hypothesis that a patient's understanding of the importance of the underlying disease being treated (HIV, hypertension) or the affect of treatment on patient-perceived symptoms (dyspepsia/reflux, depression) may influence levels of adherence.
ID Week: Comorbidity prevalence and its influence on non-ARV comedication burden among HIV positive patients - (10/04/13)
ID Week: HIV+ Individuals on ART Are At Risk of Polypharmacy: More Medication Increases Mortality - (10/04/13)
1. Edelman JE, Gordon K, Akgun K et al. HIV+ Individuals on ART Are At Risk of Polypharmacy: More Medication Increases Mortality. ID Week 2013, San Francisco, CA, October 2-6, 2013, abstract 76.
2. Koram N, Vannappargari V, Sampson T, Panozzo C. Comorbidity Prevalence and its Influence on Non-ARV Comedication Burden among HIV positive Patients. ID Week 2013, San Francisco, CA, October 2-6, 2013, abstract 323.
3. Kodama R, Skalweit M, Burant C Hirsch A. Differences in calculated adherence rates of ART and non-ART medications among HIV positive veterans. ID Week 2013, San Francisco, CA, October 2-6, 2013, abstract 684.
HCV at IDSA & ICAAC - 23 Reports - (10/11/13)
ID Week HIV Articles...
ID Week
October 2-6, 2013
San Francisco
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