title: Adherence to Post-Exposure Prophylaxis (PEP) and Incidence of HIV Seroconversion in a Major North American Cohort.
abstract: BACKGROUND
  There is limited evidence on the efficacy of post-exposure prophylaxis (PEP) for sexual exposures. We sought to determine the factors associated with adherence to treatment and describe the incidence of PEP failures in a Montreal clinic.
  
  
  METHODS
  We prospectively assessed all patients consulting for PEP following sexual exposures from October 2000 to July 2014. Patients were followed at 4 and 16 weeks after starting PEP. Treatment adherence was determined by self-report at week 4. Multivariable logistic regression was used to estimate the factors predicting adherence to treatment.
  
  
  RESULTS
  3547 PEP consults were included. Patients were mainly male (92%), MSM (83%) and sought PEP for anal intercourse (72%). Seventy-eight percent (n = 2772) of patients received a prescription for PEP, consisting of Tenofovir/Emtracitabine (TVD) + Lopinavir/Ritonavir (LPV) in 74% of cases, followed by Zidovudine/Lamivudine (CBV) + LPV (10%) and TVD + Raltegravir (RAL) (8%). Seventy percent of patients were adherent to treatment. Compared to TVD+LPV, patients taking CBV+LPV were less likely to adhere to treatment (OR 0.58, 95% CI 0.44-0.75), while no difference was observed for patients taking TVD+RAL (OR 1.15, 95% CI 0.83-1.59). First-time PEP consults, older and male patients were also more adherent to treatment. Ten treated patients seroconverted (0.37%) during the study period, yet only 1 case can be attributed to PEP failure (failure rate = 0.04%).
  
  
  CONCLUSIONS
  PEP regimen was associated with treatment adherence. Patients were more likely to be adherent to TVD-based regimens. Ten patients seroconverted after taking PEP; however, only 1 case was a PEP failure as the remaining patients continued to engage in high-risk behavior during follow-up. One month PEP is an effective preventive measure to avoid HIV infection.
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Réjean
authors.initials: R
authors.lastname: Thomas
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Chrissi
authors.initials: C
authors.lastname: Galanakis
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Vézina
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Danièle
authors.initials: D
authors.lastname: Longpré
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Boissonnault
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Huchet
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Louise
authors.initials: L
authors.lastname: Charest
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Murphy
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Benoît
authors.initials: B
authors.lastname: Trottier
authors.affiliation: Clinique médicale l'Actuel, Montreal, Quebec, Canada.
authors.forename: Nimâ
authors.initials: N
authors.lastname: Machouf
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D004338:Drug Combinations; D000068679:Emtricitabine / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000517:prevention & control*; D006679:HIV Seropositivity / Q000188:drug therapy* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D019259:Lamivudine / Q000627:therapeutic use; D061466:Lopinavir / Q000627:therapeutic use; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D056990:Post-Exposure Prophylaxis; D011792:Quebec; D019438:Ritonavir / Q000627:therapeutic use; D000068698:Tenofovir / Q000627:therapeutic use; D055815:Young Adult; D015215:Zidovudine / Q000627:therapeutic use
chemical_list: D019380:Anti-HIV Agents; D004338:Drug Combinations; C109078:lamivudine, zidovudine drug combination; D061466:Lopinavir; D019259:Lamivudine; D015215:Zidovudine; D000068698:Tenofovir; D000068679:Emtricitabine; D019438:Ritonavir