Pharmacy-refill measure of adherence to efavirenz can predict maintenance of HIV viral suppression.
The objective of this study was to determine if a lower rate of adherence (<95%) is sufficient to maintain HIV viral suppression in patients on an efavirenz-based regimen. This study was a retrospective review of pharmacy refill records at an HIV specialty pharmacy at Montefiore Medical Center's outpatient clinic. Data from 151 HIV-positive patients on an efavirenz-based regimen with at least one undetectable viral load (HIV RNA < 400 copies/mL) from December 2003 through March 2005 were reviewed. Adherence was calculated based on the formula: [(pills dispensed/pills prescribed per day/days between refills)x100%]. Calculated adherence for each time-period was correlated to the respective HIV-RNA value for that period. Of 151 patients, viral suppression was maintained in greater than 80% of time periods for adherence rates as low as 85-90%. The periods with 75-80% adherence also had higher than 85% suppression. Rates of suppression began to fall when adherence decreased to < 75%. In conclusion, lower adherence rates (<95%) on an efavirenz-based regimen were more successful in maintaining viral suppression than previously found with unboosted protease inhibitor-based regimens.
Saberi
P
P
Department of Family and Community Medicine, University of California San Francisco, US. Parya.saberi@ucsf.edu
Caswell
N
N
Amodio-Groton
M
M
Alpert
P
P
D000480:Alkynes; D048588:Benzoxazines / Q000627:therapeutic use*; D003521:Cyclopropanes; D004334:Drug Administration Schedule; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D015497:HIV-1; D006801:Humans; D008297:Male; D016347:Medical Records Systems, Computerized; D055118:Medication Adherence / Q000523:psychology*; D010607:Pharmacy Service, Hospital / Q000706:statistics & numerical data; D012189:Retrospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D019562:Viral Load; D016903:Drug Monitoring
D000480:Alkynes; D048588:Benzoxazines; D003521:Cyclopropanes; D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors; C098320:efavirenz