Relationship between plasma levels of stavudine and self reported adherence rates to triomune in HIV/AIDS patients at the Joint Clinical Research Centre, Mengo Uganda.

Abstract

INTRODUCTION: Adherence to antiretroviral therapy is mainly assessed by patient self reporting method in Uganda. The relationship between self reported adherence rates and plasma drug levels is not known. This study sought to establish the relationship between plasma stavudine levels and the self reported adherence among HIV/AIDS patients on triomune-30 in Uganda. METHODS: A cross sectional survey was carried among 236 HIV/AIDS adult patient attending the JCRC clinic in Kampala. The three months mean adherence rates were extracted from patient records. Venous blood samples were taken at least 1.5 hrs after ingestion of the last dose of the drug and samples analyzed for stavudine using high performance liquid chromatography. RESULTS: Of the 236 participants, 196 (83.1%) had >_95% mean adherence rates while 40 (16.9%) had < 95% mean adherence rate. High adherence rate correlated well with plasma stavudine levels with a sensitivity of 91.4%, a positive predictive value of 78.2%. However, this method is poor at detecting non-adherent patients with a specificity of only 38.2% and a negative predictive value of 65% (OR=6.72, C1=95%). Adherent patients were seven times more likely to have plasma stavudine levels within therapeutic range than the non-adherent. CONCLUSION: Self-reported adherence is a good method for predicting plasma drug levels of stavudine in patients. However, this method is significantly limited in identifying the non-adherent patient.