Variability in non-nucleoside reverse transcriptase and protease inhibitors concentrations among HIV-infected adults in routine clinical practice.
OBJECTIVE
The objective of this study was to assess interindividual variability in plasma trough concentrations of non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) among HIV-infected adults in an outpatient routine clinical practice setting.


METHODS
The study included 117 patients who attended our clinic for routine outpatient blood tests and who were receiving antiretroviral therapy which included NNRTI or PI. Patients were not informed that drug concentrations were going to be assessed until blood sampling. The time of the last antiretroviral treatment intake and blood sampling were recorded. Drug concentrations were considered optimal if they were above the proposed minimum effective concentration. In addition, efavirenz, nevirapine and atazanavir concentrations were considered potentially toxic if they were higher than 4.0 mg l(-1), 6.0 mg l(-1), and 0.85 mg l(-1), respectively.


RESULTS
Overall, interindividual variability in NNRTI and PI plasma concentrations was approximately 50%, and only 68.4% of the patients had drug concentrations within the proposed therapeutic range. Inappropriate adherence only explained 35% of subtherapeutic drug concentrations.


CONCLUSIONS
Interindividual variability in trough concentrations of NNRTI and PI among HIV-infected adults is large in routine clinical practice, with drug concentrations being outside the therapeutic window in a significant proportion of patients. Therapeutic drug monitoring may be useful to guide antiretroviral therapy in clinical practice.
Moltó
José
J
'Lluita contra la SIDA' Foundation, Germans Trias i Pujol Hospital, Badalona, Barcelona, Spain. jmolto@ns.hugtip.scs.es
Blanco
Asunción
A
Miranda
Cristina
C
Miranda
José
J
Puig
Jordi
J
Valle
Marta
M
Delavarga
Meritxell
M
Fumaz
Carmina R
CR
Barbanoj
Manuel José
MJ
Clotet
Bonaventura
B
D000328:Adult; D019380:Anti-HIV Agents / Q000097:blood* / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data; D011320:Primary Health Care; D011480:Protease Inhibitors / Q000097:blood / Q000378:metabolism* / Q000627:therapeutic use; D018894:Reverse Transcriptase Inhibitors / Q000097:blood / Q000378:metabolism* / Q000627:therapeutic use
D019380:Anti-HIV Agents; D011480:Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors