Pharmacokinetics of nevirapine and lamivudine in patients with HIV-1 infection
Journal Title: The AAPS Journal - Year 2000, Vol 2, Issue 1
Abstract
The purpose of this parallel treatment group, double-blind. multicenter study was to lharacterize the pharmacokinetics of nevirapine and lamivudine when coadministered to patients with the HIV-1 infection. This pharmacokinetic interaction study was nested within a larger Phase III clinical trial conducted to characterize the safety and efficacy of coadministered nevirapine and lamivudine. One hundred HIV-1 infected patients with CD4+ lymphocyte counts=200 cells/mm3 and who were on a background of nucleoside (zidovudine [ZDV], didanosine [ddl], zalcitabine [ddC], stavudine [d4T]) therapy were randomly assigned to be treated with either nucleoside+ lamivudine+nevirapine or nucleoside+lamivudine+ placebo. Each patient underwent blood sampling at defined times for the purpose of determining the concentration of nevirapine in plasma and lamivudine in serum under steady-state conditions. Each patient was also monitored closely for concomitant administration of other drugs, including ZDV, ddl, ddC, d4T and cotrimoxazole. The pharmacokinetics of nevirapine and lamivudine were characterized using nonlinear mixed-effects modeling. There were no reported serious adverse events during the 40-day pharmacokinetic study. The results of the modeling analysis revealed that nevirapine had no effect on the pharmacokinetics of lamivudine. Estimates of the apparent clearance for nevirapine (CL/F=3.3 L/hour; 95% confidence interval [Cl] 2.9 to 3.7 L/hour) and lamivudine (CL/F 27.6 L/hour; 95% Cl 22 to 33.2 L/hour) were consistent with the values reported in earlier trials. However, the results also showed that concomitant administration of lamivudine with cotrimoxazole resulted in a 31% reduction in the apparent clearance of lamivudine, resulting in a 43% increase in the average steady-state lamivudine serum concentrations. These results indicate that chronic concurrent administration of cotrimoxazole with lamivudine may significantly affect the steady-state pharmacokinetics of lamivudine.
Authors and Affiliations
John P. Sabo, Michael J. Lamson, Gerhard Leitz, Chan-Loi Yong, Thomas R. MacGregor
Wet granulation fine particle ethylcellulose tablets: Effect of production variables and mathematical modeling of drug release
In the present study, the applicability of fine particle ethylcellulose (FPEC) to produce matrix tablets by a wet granulation technique was evaluated. The effect of various formulation and process variables, such as FPEC...
Progressively Reducing Regulatory Burden
Principles of dissolution science have been applied to allow waiver of in vivo bioequivalence studies for oral immediate release solid dosage forms, providing certain stipulations are met. This approach reduces regulator...
A novel method for the determination of biliary clearance in humans
Biliary excretion is an important route of elimination and the biliary tract is a potential site of toxicity for many drugs and xenobiotics. Quantification of biliary excretion in healthy human volunteers is logistically...
Determination of membrane protein glycation in diabetic tissue
Diabetes-associated hyperglycemia causes glycation of proteins at reactive amino groups, which can adversely affect protein function Although the effects of glycation on soluble proteins are well characterized, there is...
Pharmacodynamic Studies to Demonstrate Bioequivalence of Oral Inhalation Products
In the session on “Pharmacodynamic studies to demonstrate efficacy and safety”, presentations were made on methods of evaluating airway deposition of inhaled corticosteroids and bronchodilators, and syste...