Liver function parameters in HIV/HCV co-infected patients treated with amprenavir and ritonavir and correlation with plasma levels.

Acute liver toxicity is a frequent adverse event that occurs during antiretroviral therapy and was observed in 6-30% of the patients on treatment, especially in presence of HCV coinfection (Cooper et al., 2002, Maida et al., 2006, Sulkowski et al., 2000). A correlation between HCV-associated liver-fibrosis severity and the risk of HAART associated hepatoxicity has been demonstrated (Aranzabal et al., 2005, Sulkowski et al., 2004). This high liver toxicity rate might be due to increased drug exposure in patients with liver disease (Veronese et al., 2000). It has been reported that patients with chronic hepatitis C show significantly reduced CPY3A4 and CYP2D6 activity in comparison with healthy volunteers (Becquemont et al., 2002). The aim of this study was to evaluate the liver function tests in HCV-co-infected patients treated with fos-amprenavir and ritonavir.

Amprenavir and ritonavir plasma concentrations in HIV-infected patients treated with fosamprenavir/ritonavir with various degrees of liver impairment.

OBJECTIVES: The purpose of this study was to evaluate the steady-state pharmacokinetics of amprenavir and ritonavir in HIV-infected patients with different degrees of hepatic impairment. METHODS: HIV-positive patients receiving fosamprenavir/ritonavir (700/100 mg twice daily) were included. Patients were classified into three groups: (i) chronic hepatitis; (ii) liver cirrhosis; (iii) normal liver function. Serial blood samples for steady-state amprenavir and ritonavir pharmacokinetics (>14 days on treatment) were collected in the fasting state before the morning dose (C(trough)) and then 1, 2, 3, 4, 6, 8, 10 and 12 h after drug intake. Amprenavir and ritonavir plasma concentrations were determined by HPLC. RESULTS: Twenty-one HIV-infected patients were included. Seven had chronic hepatitis, eight had liver cirrhosis and six patients were in the control group. Amprenavir AUC(0-12), AUC(0-infinity), C(max) and C(ss) were increased by 50% to 60% in the cirrhotic group when compared with controls, whereas CL/F was decreased by 40%. Patients with chronic hepatitis showed a significant increase in AUC(0-12), C(max) and C(ss) values when compared with controls. Ritonavir pharmacokinetics was different only in cirrhotic patients when compared with controls. Liver function parameters at weeks 4, 12 and 24 were not different from baseline in any of the groups. Overall, a significant correlation between amprenavir AUC(0-12) and total bilirubin values on the day of pharmacokinetic analysis was found (r = 0.64, P = 0.003). CONCLUSIONS: On the basis of these data and also of data available in the literature, it seems reasonable to adapt the dose of fosamprenavir and/or ritonavir exclusively in the presence of adverse events, possibly related to protease inhibitors (i.e. liver toxicity), in subjects with high drug plasma levels. Therapeutic drug monitoring is advised in the management of these patients.

Higher plasma lopinavir concentrations are associated with a moderate rise in cholestasis markers in HIV-infected patients.

OBJECTIVES: The aim of this study was to evaluate the correlation between liver function markers (necrosis and cholestasis) and plasma lopinavir levels in a cohort of HIV-infected patients treated with lopinavir and ritonavir. PATIENTS AND METHODS: The blood samples for determining steady-state C(trough) lopinavir levels and analysing liver function were drawn from fasting patients. Steady-state C(trough) lopinavir levels, liver function and immuno-virological markers were assessed on the same day. Plasma lopinavir and ritonavir levels were determined by means of high-performance liquid chromatography. RESULTS: One hundred and forty-nine patients were included in the analysis [57 were HCV co-infected (34%) and 10 were HBV co-infected (6.7%)]; they had been treated with lopinavir/ritonavir for a median of 232 days (range 132-282). All patients received lopinavir/ritonavir [400/100 mg twice daily or 533/133 mg twice daily if amprenavir or a non-nucleoside reverse transcriptase inhibitor (NNRTI) was part of therapy] and concomitant therapy with NRTI(s). Median (interquartile) lopinavir trough levels were 6391 ng/mL (4121-8726), 5662 (3585-8893) and 6819 ng/mL (5324-8726) in the patients with HIV alone and those with HIV/HCV (or HBV) co-infection, respectively (P = not significant). Univariate analysis showed a significant association between the cholestasis markers and C(trough) lopinavir level. Multivariate analysis selected only gamma glutamyltranspeptidase (GGT) (OR = 1.010, 95% CI: 1.002-1.021) as being independently associated with plasma lopinavir levels of >6425 ng/mL; alkaline phosphatase (OR = 1.004, 95% CI: 1.000-1.010; P = 0.08) and total bilirubin (OR = 3.118, 95% CI: 0.980-11.715; P = 0.07) were not associated. CONCLUSIONS: Elevated lopinavir concentrations are associated with raised GGT.