Browsing by Author "Chepkirui C. Philomena"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Determination of Nevirapine Levels in Hair and Plasma Samples of People Living With HIV in Kenya Using HPLC-UV and LC-MS/MS Techniques
    (Kenyatta University, 2025-01) Chepkirui C. Philomena
    Monitoring the response to antiretroviral drugs (ARVs) in patients is crucial for effective HIV treatment. Antiretroviral therapy (ART) is pivotal in mitigating the epidemic of human immunodeficiency virus (HIV), particularly in the prevention of vertical transmission of the virus. Monitoring of the adherence of the patients to ART is imperative for gauging their response to antiretroviral drugs (ARVs) and identifying treatment inadequacies. Methods previously used in monitoring adherence, like measuring ARV drug concentrations in blood and urine, are limited by their ability to only reflect doses taken within 1 to 2 days before the day of sampling. In response to these limitations, hair testing has emerged as a preferred tool for assessing chronic exposure to various substances, owing to its extended detection window. Therefore, this study determined the viability of hair samples for adherence monitoring, serving as an alternative to blood-based ARV analysis. Furthermore, it investigated the potential of using high-performance liquid chromatography with a UV detector (HPLC-UV) as a cost-effective substitute of liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique, particularly in resource-limited settings like Kenyan hospitals. The research focused on nevirapine (NVP), a fundamental component of Kenya's first-line ART regimen. Hair and blood samples were collected from consenting patients with varying viral loads. NVP levels in these samples were compared using HPLC-UV and LC-MS/MS instruments. Significantly, the findings reveal no substantial difference between hair and plasma NVP concentrations, as verified by statistical tests. A robust positive association between the two measurement methods further validates the utility of HPLC-UV for monitoring ARV drug concentrations in both hair and blood in resource-limited settings. Quantitatively, the median (IQR) NVP levels in hair and blood samples were 67.80 ng/mL and 706.50 ng/mL for HPLC-UV, and 36.80 ng/mL and 19.32 ng/mL for LC-MS/MS, respectively. The Wilcoxon signed-rank test, yielding a statistical result of (Z = -0.93, p > 0.05), confirms no significant difference between hair and plasma NVP concentrations. The Spearman rank test indicates a significant positive association between NVP concentrations analysed using both LC-MS/MS and HPLC-UV (r2 = 0.995, p < 0.05) for hair samples, and (r2 = 0.966, p < 0.05) for plasma samples. This research demonstrated the potential of using hair testing as a non-invasive, cost effective means to quantitatively monitor ARV adherence among people living with HIV, particularly in regions lacking traditional laboratory facilities and skilled personnel for blood sampling. Importantly, it does not suggest replacing plasma testing with hair testing in all scenarios; instead, these methods can complement each other for a comprehensive assessment of adherence to antiretroviral therapy