Elevated Plasma Concentrations of Protease Inhibitors and Nonnucleoside Reverse Transcriptase Inhibitors in Patients Coinfected with Human Immunodeficiency Virus and Hepatitis B or C: Case Series and Literature Review

Raltegravir pharmacokinetics before and during treatment with ombitasvir, paritaprevir/ritonavir plus dasabuvir in adults with human immunodeficiency virus-1 and hepatitis C virus coinfection: AIDS Clinical Trials Group sub-study A5334s

AIMS

AIDS Clinical Trials Group study A5334s evaluated the pharmacokinetics of raltegravir before and during combined administration of ombitasvir, paritaprevir/ritonavir, plus dasabuvir (OBV/PTV/r + DSV) and weight-based ribavirin in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfected adults. The pharmacokinetics of OBV/PTV/r + DSV during raltegravir coadministration were also characterized.

METHODS

Adults living with HIV/HCV coinfection receiving steady-state raltegravir (400 mg twice daily) with 2 nucleos(t)ide analogues were enrolled. Pharmacokinetics of raltegravir were assessed prior to HCV therapy, and 4 weeks later following initiation of OBV/PTV/r (25/150/100 mg) once daily + DSV (250 mg) twice daily. Geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were used to compare the following: raltegravir pharmacokinetics with HCV therapy (week 4) vs before HCV therapy (week 0); OBV/PTV/r and DSV pharmacokinetics vs historical healthy controls; raltegravir pharmacokinetics at week 0 vs historical control adults living with HIV.

RESULTS

Eight of 11 participants had decreased raltegravir exposures after initiation of HCV therapy. The GMRs (90% CI) for maximum concentration and area under the concentration-time curve of raltegravir with vs without HCV therapy were 0.68 (0.38-1.19) and 0.82 (0.58-1.17), respectively. Comparing OBV/PTV/r pharmacokinetics in healthy controls, A5334s study participants demonstrated generally lower maximum concentration and area under the concentration-time curve values by 41-82% and 4-73%, respectively. Raltegravir exposures tended to be higher in A5334s study participants compared to adults living with HIV.

CONCLUSIONS

The majority of participants' plasma raltegravir exposures were lower after initiation of HCV therapy in coinfected adults; however, confidence intervals were wide.

Review article: prescribing medications in patients with cirrhosis - a practical guide

BACKGROUND

Most drugs have not been well studied in cirrhosis; recommendations on safe use are based largely on experience and/or expert opinion, with dosing recommendations often based on pharmacokinetic (PK) changes.

AIM

To provide a practical approach to prescribing medications for cirrhotic patients.

METHODS

An indexed MEDLINE search was conducted using keywords cirrhosis, drug-induced liver injury, pharmacodynamics (PDs), PKs, drug disposition and adverse drug reactions. Unpublished information from the Food and Drug Administration and industry was also reviewed.

RESULTS

Most medications have not been adequately studied in cirrhosis, and specific prescribing information is often lacking. Lower doses are generally recommended based on PK changes, but data are limited in terms of correlating PD effects with the degree of liver impairment. Very few drugs have been documented to have their hepatotoxicity potential enhanced by cirrhosis; most of these involve antituberculosis or antiretroviral agents used for HIV or viral hepatitis. Paracetamol can be used safely when prescribed in relatively small doses (2-3 g or less/day) for short durations, and is recommended as first-line treatment of pain. In contrast, NSAIDs should be used cautiously (or not at all) in advanced cirrhosis. Proton pump inhibitors have been linked to an increased risk of spontaneous bacterial peritonitis (SBP) in cirrhosis and should be used with care.

CONCLUSIONS

Most drugs can be used safely in cirrhosis, including those that are potentially hepatotoxic, but lower doses or reduced dosing frequency is often recommended, due to altered PKs. Drugs that can precipitate renal failure, gastrointestinal bleeding, SBP and encephalopathy should be identified and avoided.

Pharmacokinetics of Nelfinavir in Subjects With Hepatic Impairment

HIV-seronegative subjects with hepatic impairment (6 mild, 6 moderate) and 12 matched healthy controls received nelfinavir 1250 mg every 12 hours with food for 2 weeks. Mild impairment did not significantly change nelfinavir or major metabolite (M8) steady-state exposures compared with controls. In subjects with moderate impairment, steady-state area under the plasma concentration time-curve over the dosing interval and maximum observed plasma concentrations were 62% and 22% higher for nelfinavir than for controls, and for M8 were 46% and 35% of control values. With increasing degree of impairment, no trend toward increase in unbound nelfinavir was observed, but there was an increase in unbound M8 levels. Nelfinavir was safe and well tolerated. One subject with moderate impairment was discontinued because of transient leucopenia. Observed changes are unlikely to affect nelfinavir efficacy or markedly influence safety. Dose reduction of nelfinavir does not appear necessary for subjects with mild/moderate impairment. Further long-term evaluations of nelfinavir pharmacokinetics and safety in HIV-seropositive subjects with hepatic impairment may be useful.

A pilot study on the efficacy, pharmacokinetics and safety of atazanavir in patients with end-stage liver disease

OBJECTIVES

Antiretroviral combinations including atazanavir are currently not recommended in HIV-infected patients with end-stage liver disease (ESLD). The objective of our study was to evaluate efficacy, pharmacokinetics and safety of unboosted atazanavir in HIV-infected patients with ESLD screened for orthotopic liver transplantation (OLT(x)). Patients and methods Single-arm, 24 week pilot study. Atazanavir-naive patients undergoing highly active antiretroviral therapy were switched to atazanavir 400 mg/day plus two non-thymidine nucleoside reverse transcriptase inhibitors. Results Fifteen patients (10 males and 5 females) were included. In the study period, 2 patients were transplanted and 10 completed 24 weeks of atazanavir treatment. Median area under the concentration-time curve at week 4 was 19 211 ng.h/mL (IQR = 8959-27 500). At week 24, median atazanavir trough concentrations (C(trough)) per patient calculated across the study were above the minimum effective concentration (MEC = 100 ng/mL) in 8 of 10 subjects. Atazanavir C(trough) time-point values were always above the MEC in five patients. The other three subjects experienced only one determination below the MEC, with median atazanavir C(trough) levels across the study being above the MEC in two of them. At 8 of 11 time-points when atazanavir and proton pump inhibitors (PPIs) were co-administered and at 16 of 19 time-points in which patients had a concomitant tenofovir association, atazanavir C(trough) was above the MEC. Conclusions Unboosted atazanavir showed a favourable pharmacokinetic profile and was able to maintain or gain immuno-virological eligibility for OLT(x) in all patients. Limited biochemical toxicities (including unconjugated hyperbilirubinaemia) and allowance of concomitant administration of tenofovir and PPIs were observed.

Efavirenz concentrations in HIV-infected patients with and without viral hepatitis

AIMS

Data on efavirenz in HIV/viral hepatitis co-infected patients is non-consensual, probably due to liver function heterogeneity in the patients included.

METHODS

A case control study was performed on 27 HIV-infected patients, with controlled and homogenous markers of hepatic function, either mono-infected or co-infected with HBV/HCV, to ascertain the influence of viral hepatitis on efavirenz concentrations over a 2-year follow-up period.

RESULTS

No differences were found in efavirenz concentrations between groups both during and at the end of the follow-up period: control (2.43 +/- 1.91 mg l(-1)) vs. co-infected individuals (2.37 +/- 0.37 mg l(-1)).

CONCLUSION

It was concluded that HBV/HCV infections in themselves do not predispose to an overexposure to efavirenz.

The spectrum of hepatic functional impairment in compensated chronic hepatitis C: results from the Hepatitis C Anti-viral Long-term Treatment against Cirrhosis Trial

BACKGROUND

The spectrum of functional impairment in patients with compensated chronic hepatitis C is incompletely defined.

AIM

To define hepatic impairment by quantitative tests (quantitative liver function tests) and correlate results with disease severity in patients with chronic hepatitis C.

METHODS

We studied 285 adult patients with chronic hepatitis C prior to treatment in the Hepatitis C Anti-viral Long-term Treatment against Cirrhosis Trial; 171 had Ishak fibrosis stages 2-4 (fibrosis) and 114 had stage 5 or 6 (cirrhosis). None had had clinical decompensation. A battery of 12 quantitative liver function test assessed the spectrum of hepatic microsomal, mitochondrial and cytosolic functions, and hepatic and portal blood flow.

RESULTS

Twenty-six to 63% of patients with fibrosis and 45-89% with cirrhosis had hepatic impairment by quantitative liver function test; patients with cirrhosis had the greatest impairment (P-value ranging from 0.15 to <0.0001). Cholate Cl(oral), cholate shunt and perfused hepatic mass correlated with cirrhosis, stage of fibrosis (r = -0.51, +0.49, -0.51), varices and variceal size (r = -0.39, +0.36, -0.41). PHM < 95 and cholate shunt >35% identified 91% of patients with medium- or large-sized varices.

CONCLUSIONS

Hepatic impairment is common in compensated patients with fibrosis or cirrhosis because of chronic hepatitis C. Cholate shunt, and cholate Cl(oral) and perfused hepatic mass, identify patients at risk for cirrhosis or varices.