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Patient characteristics and treatment outcomes associated with protease inhibitor (PI) use in the Asia-Pacific region

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Journal of the International AIDS Society200811 (Suppl 1) :P72

  • Published:


  • Protease Inhibitor
  • Viral Load
  • High Income Country
  • Multiple Logistic Regression Analysis
  • Detectable Viral Load

Purpose of the study

PI-based regimens are rarely used in developing countries due to the high cost and low availability. We evaluated characteristics of patients initiating PI-based therapy according to previous antiretroviral (ARV) exposure; factors associated with initiating a PI therapy using newer vs. older PIs; and detectable viral load (VL) following the initiation of a PI-based regimen.


This analysis includes all patients initiating a PI-based regimen. ARV exposure was categorised according to the initiation of PI-based therapy: naïve (no previous ARV), 1st, 2nd, >3rd switches; a switch was defined as starting or stopping any drug in a regimen. Newer PIs were defined as those that were approved by the US FDA after January 1, 2000. Detectable VL at 12 months was defined as VL > 400 copies/mL. Characteristics at PI initiation were evaluated. Logistic regression was used to determine factors associated with initiating a newer PI and detectable VL at 12 months after a PI initiation.

Summary of results

1,106 patients initiated PI-based therapy, [618 (56%) were naïve to PI-based therapy] and the main reason for a change to PI was treatment failure (26%). Following PI initiation, 793 (72%) had VL measurements at 12 months. For multiple logistic regression analysis, switch patients were less likely to use a newer PI [1st, odds ratio (OR) = 0.22, p < 0.001; 2nd, OR = 0.12, p < 0.001; and >3rd switches, OR = 0.14, p < 0.001; vs. naïve]. Being from a high income country (vs. mid/low income OR = 1.67, p = 0.005), patent PI (vs. generic PI, OR = 18.64, p < 0.001), and years from HIV diagnosis to PI initiation (OR = 1.07 per year, p = 0.017) were associated with more use of a newer PI. Overall, 22% (176) of patients had detectable VL at 12 months following the PI initiation. Among naïve patients, the only predictor for detectable VL was baseline CD4 [CD4 200–350 cells/μL, OR = 0.28, p = 0.001; CD4 > 350 cells/μL, OR = 0.73, p = 0.445; vs. CD4 <200 cells/μL]. In experienced patients, higher baseline CD4 [CD4 200–350 cells/μL, OR = 0.39, p = 0.024; CD4 > 350 cells/μL OR = 0.69, p = 0.469; vs. CD4<200 cells/μL] was less likely to have a detectable VL. Being from a high income country (vs. mid/low income, OR = 1.80, p = 0.034) was more likely to associate with detectable VL.


Newer PI-based regimens were prescribed more in high income countries than in other countries in Asia. Short-term virological outcomes following PI therapy in our cohort were good, and were related with CD4 count at time of initiation.

Authors’ Affiliations

Institute of Infectious Diseases, Pune, India
Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
National Centre in HIV Epidemiology and Clinical Research, Sydney, Australia
Tan Tock Seng Hospital, Singapore, Singapore
YRG Centre for AIDS Research and Education, Chennai, India
Gold Coast Sexual Health Clinic, Queensland, Australia
Outcomes Research and Health Technology Assessment Global Human Health Merck and Co., Inc., NJ, USA
The Thai Red Cross AIDS Research Centre, Bangkok, Thailand


© Pujari et al; licensee BioMed Central Ltd. 2008

This article is published under license to BioMed Central Ltd.