Clinical Use of a Simultaneous HPLC Assay for Indinavir, Saquinavir, Ritonavir, and Nelfinavir in Children and Adults

Abstract

Protease inhibitor (PI) monitoring may improve the care of human immunodeficiency virus (HIV)-infected patients; however, pediatric data are limited. A high-performance liquid chromatographic (HPLC) assay developed for the simultaneous determination of indinavir, ritonavir, saquinavir, and nelfinavir in 0.2 mL of plasma was used to quantify PI concentrations in HIV patients. The reliability, sensitivity, and specificity of the assay were first verified in stored adult samples. Later, blood collected prospectively from patients aged 2.9 to 42 years of age (10 adults aged 24 to 42 and 15 children aged 2.9 to 18 years) was tested. Nondetectable (below 25-50 ng/mL) concentrations (ND) were found in 33% of adult samples and 24% of pediatric samples. Four patients taking from 13.7 to 28 mg/kg/d of ritonavir (mean of 21.3) had concentrations ranging from ND to 11.4 microg/mL, quite different from predicted values. Correctable, important clinical problems including drug-drug interactions, drug administration problems, and confirmed noncompliance were identified and corrected using modern therapeutic drug monitoring (TDM) techniques. Routine PI monitoring and interpretation (TDM) could improve the care of adult and pediatric HIV patients; especially in patients who do not respond as expected to treatment, develop viral resistance or toxicity, and have questionable compliance.

Conventional HPLC Method Used for Simultaneous Determination of the Seven HIV Protease Inhibitors and Nonnucleoside Reverse Transcription Inhibitor Efavirenz in Human Plasma

“…When antiretroviral drugs are administered at the recommended dose, plasma concentrations are expected in the 0.3 to 8.2 mg/ml range for APV, 12) the 0.2 to 10 mg/ml range for ATV, 17) the 0.1 to 7.7 mg/ml range for IDV, 18,19) the 5.5 to 9.6 mg/ml range for LPV, 12) the 0.1 to 4.0 mg/ml range for NFV, 18,20) the 0.1 to 11.2 mg/ml range for RTV, 18,20) the 0 to 0.2 mg/ml range for SQV, 18) and the 1 to 4 mg/ml range for EFV. 21) Our method successfully covers these regions with good precision and accuracy.…”

Docosahexaenoic acid (DHA) inhibits saquinavir metabolism in-vitro and enhances its bioavailability in rats

“…Extraction of saquinavir from plasma samples was performed according to the method of Walson et al (2003). The frozen plasma samples were thawed and vortexed.…”

Ionic liquid‐based dispersive liquid–liquid microextraction followed by RP‐HPLC determination of saquinavir in rat serum: application to pharmacokinetics

“…Quantitative determination of SQV from Caco-2 cell monolayers by HPLC-UV was reported by Ucpinar and Stavchansky (2003). Walson et al (2003) developed a simultaneous assay of indinavir, saquinavir, ritonavir and nelfinavir in children and adults by HPLC for clinical use. Berginc et al (2010) studied the pharmacokinetic method of SQV while Buchanan et al (2008) reported pharmacokinetics of saquinavir after intravenous and oral dosing of saquinavir hydroxybutenyl-β-cyclodextrin formulations.…”