title: Polypharmacy and risk of antiretroviral drug interactions among the aging HIV-infected population.
abstract: BACKGROUND
  Among aging HIV-infected adults, polypharmacy and its consequences have not been well-described.
  
  
  OBJECTIVE
  To characterize the extent of polypharmacy and the risk of antiretroviral (ARV) drug interactions among persons of different ages.
  
  
  METHODS
  Cross-sectional analysis among patients within the HIV Outpatient Study (HOPS) cohort who were prescribed ARVs during 2006-2010.
  
  
  METHODS
  We used the University of Liverpool HIV drug interactions database to identify ARV/non-ARV interactions with potential for clinical significance.
  
  
  RESULTS
  Of 3,810 patients analyzed (median age 46 years, 34 % ≥ 50 years old) at midpoint of observation, 1,494 (39 %) patients were prescribed ≥ 5 non-ARV medications: 706 (54 %) of 1,312 patients ≥ 50 years old compared with 788 (32 %) of 2,498 patients < 50 years. During the five-year period, the number of patients who were prescribed at least one ARV/non-ARV combination that was contraindicated or had moderate or high evidence of interaction was 267 (7 %) and 1,267 (33 %), respectively. Variables independently associated with having been prescribed a contraindicated ARV/non-ARV combination included older age (adjusted odds ratio [aOR] per 10 years of age 1.17, 95 % CI 1.01-1.35), anxiety (aOR 1.78, 95 % CI 1.32-2.40), dyslipidemia (aOR 1.96, 95 % CI 1.28-2.99), higher daily non-ARV medication burden (aOR 1.13, 95 % CI 1.10-1.17), and having been prescribed a protease inhibitor (aOR 2.10, 95 % CI 1.59-2.76). Compared with patients < 50 years, older patients were more likely to have been prescribed an ARV/non-ARV combination that was contraindicated (unadjusted OR 1.44, 95 % CI 1.14-1.82), or had moderate or high evidence of interaction (unadjusted OR 1.29, 95 % CI 1.15-1.44).
  
  
  CONCLUSIONS
  A substantial percentage of patients were prescribed at least one ARV/non-ARV combination that was contraindicated or had potential for a clinically significant interaction. As HIV-infected patients age and experience multiple comorbidities, systematic reviews of current medications by providers may reduce risk of such exposures.
authors.affiliation: Temple University School of Pharmacy, 3307 N. Broad St., Philadelphia, PA, 19140, USA, carol.holtzman@temple.edu.
authors.forename: Carol
authors.initials: C
authors.lastname: Holtzman
authors.forename: Carl
authors.initials: C
authors.lastname: Armon
authors.forename: Ellen
authors.initials: E
authors.lastname: Tedaldi
authors.forename: Joan S
authors.initials: JS
authors.lastname: Chmiel
authors.forename: Kate
authors.initials: K
authors.lastname: Buchacz
authors.forename: Kathleen
authors.initials: K
authors.lastname: Wood
authors.forename: John T
authors.initials: JT
authors.lastname: Brooks
mesh_terms: D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D004363:Drug Utilization / Q000706:statistics & numerical data; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019338:Polypharmacy; D012307:Risk Factors
chemical_list: D019380:Anti-HIV Agents