Medication use and medical comorbidity in patients with chronic hepatitis C from a US commercial claims database: high utilization of drugs with interaction potential

Evaluation of US Food and Drug Administration Drug Label Recommendations for Coadministration of Antivirals and Acid-Reducing Agents

Coadministration with acid-reducing agents (ARAs), including proton pump inhibitors (PPIs), histamine H2 -receptor antagonists (H2 blockers), and antacids has been demonstrated to reduce antiviral exposure and efficacy. Therefore, it is essential that US Food and Drug Administration (FDA) drug labels include recommendations to manage these drug-drug interactions (DDIs). This investigation analyzed information in FDA drug labels to manage DDIs between ARAs and antivirals approved from 1998 to 2019. To ascertain clinical adoption, we assessed whether FDA label recommendations were incorporated into current antiviral clinical practice guidelines. We identified 82 label recommendations for 43 antiviral approvals. Overall, 56.1% of recommendations were deemed clinically actionable, with the most common actionable management strategies being dose adjustment during coadministration (40.2%) and coadministration not recommended (9.8%). The sources informing DDI recommendations were clinical DDI studies (59.8%) and predictions of altered exposure (40.2%). Antivirals with low aqueous solubility were more likely to have label recommendations and were more commonly investigated using clinical DDI studies (P < 0.01). For recommendations informed by clinical DDI studies, changes in drug exposure were associated with actionable label recommendations (P < 0.01). The frequency of exposure changes in clinical DDI studies was similar across antiviral indications, but exposure changes were numerically higher for antacids (71.4%) relative to PPIs (42.9%) and H2 blockers (28.6%). Of DDI pairs identified within drug labels, 76.8% were included in guidelines, and recommended management strategies were concordant in 90.5% of cases. Our findings demonstrate that current regulatory oversight mostly (but not completely) results in actionable label recommendations to manage DDIs for high-risk antivirals.

The impact of proton pump inhibitors in liver diseases and the effects on the liver

In this systematic and comprehensive overview, we aimed to evaluate the impact of proton pump inhibitors (PPIs) on chronic liver diseases, especially on cirrhosis. A manual and comprehensive search of the PubMed database was conducted to obtain relevant literatures. PPIs altered the composition and function of the intestinal microflora and might lead to small intestinal bacterial overgrowth and bacterial translocation, which were associated with adverse effects in liver diseases. They might increase the risk of hepatic encephalopathy, spontaneous bacterial peritonitis, infections, and are related to an increased mortality in cirrhosis. PPIs might lead to an increased risk of hepatocellular carcinoma, although the mechanism is unknown, and the results are controversial. PPIs also had an impact on the direct-acting antiviral regimen in patients with chronic hepatitis C. They were associated with an increased risk of liver abscess and increased mortality. Additionally, PPIs might lead to metabolic risk events, such as liver steatosis and weight gain. PPIs are associated with several adverse outcomes in liver diseases. Cautious use of PPIs is recommended and clinicians should be aware of the indications for their use in patients with liver diseases.

Influence of Piperine and Omeprazole on The Regional Absorption of Daclatasvir from Rabbit Intestine

The study assessed the site dependent intestinal absorption of daclatasvir and investigated the effects of piperine and omeprazole on such absorption utilizing in situ rabbit intestinal perfusion technique. The intestinal absorption of daclatasvir was assessed in four segments: duodenum, jejunum, ileum, and colon. The effect of co-perfusion with omeprazole was monitored through the tested anatomical sites. The effect of piperine, a P-glycoprotein (P-gp) inhibitor on daclatasvir absorption from jejunum and ileum was tested. The results showed that daclatasvir was incompletely absorbed from the rabbit small and large intestine. The absorptive clearance per unit length (PeA/L) was site dependent and was ranked as colon > duodenum > jejunum > ileum. This rank is the opposite of the rank of P-gp intestinal content suggesting possible influence for P-gp. Co-perfusion with omeprazole increased PeA/L and this was evidenced also with reduced the L95% of daclatasvir from both small and large intestinal segments. Significant enhancement in daclatasvir absorption through jejunum and ileum was shown in presence of piperine. Daclatasvir showed site dependent intestinal absorption in a manner suggesting its affection by P-gp efflux. This effect was inhibited by piperine. Co-administration of daclatasvir with omeprazole can enhance intestinal absorption a phenomenon which requires extension to human pharmacokinetic investigation. This article is protected by copyright. All rights reserved.

Elbasvir/grazoprevir administered for 12 weeks via percutaneous endoscopic gastrostomy tube achieves sustained virologic response: A case report and a review of the literature

Enteral tubes are necessary for certain patients; however, medication absorption can be affected by this route of administration potentially resulting in decreased efficacy. All first-line treatments for Hepatitis C Virus (HCV) infection are only available as tablets and may have decreased absorption if administered via an enteral tube. This report describes the first case of a pegylated interferon and ribavirin treatment-experienced patient who successfully achieved HCV cure after 12 weeks of elbasvir/grazoprevir administered via percutaneous gastrostomy tube. We further review the available pharmacokinetic and clinical literature regarding administration via enteral feeding tubes for all first-line direct-acting antivirals (DAAs). The literature suggests that crushed administration can be considered for DAAs in patients with gastric access. However, caution should be exercised in patients with extragastric enteral tubes and in those with altered gastrointestinal tract anatomy.

Direct antiviral agents for hepatitis C and drug interaction risk: A retrospective cohort study with real and simulated data on medication interaction, prevalence of comorbidities and comedications

Introduction and aim

Comorbidities and comedication are common in patients with hepatitis C, which could result in a risk of drug-drug interaction. The objective of this study was to evaluate the prevalence of comorbidities, comedication and drug-drug interactions involving direct-acting antivirals in this population.

Methods

Comorbidities and comedications were evaluated in a retrospective cohort of hepatitis C patients. Drug-drug interactions were estimated in real life and with simulated data on comedications following drug regimens: telaprevir; elbasvir/grazoprevir, ombitasvir/paritaprevir/r/ritonavir (2D regimen), and sofosbuvir/simeprevir, sofosbuvir/daclatasvir, sofosbuvir/ledipasvir; 2D/dasabuvir (3D regimen); glecaprevir/pibrentasvir and sofosbuvir/velpatasvir/voxilaprevir. The interactions were evaluated according to the University of Liverpool database. Statistical analysis was performed by SPSS^® 18.0.

Results

Data from 1433 patients with hepatitis C were evaluated. The mean patient age was 51.7 years (SD ± 10.7), and 50.6% were female. Direct-acting antivirals were prescribed for 345 (24.1%) patients, and a sustained virological response occurred in 264 (76.5%). The main comorbidities were systemic arterial hypertension [436 (30.4%)], diabetes mellitus [352 (24.6%)] and depression [130 (9.1%)]. The mean number of comorbidities was 1.52 (median [IQR] of 1.00 [1.00–2.00]). The mean number of comedications was 3.16 (median [IQR] of 3.00 [1.00–5.00]). A total of 12916 drug-drug interactions were found, of which 1.859 (14.4%) were high risk, with a mean of 1.29 ± 3.13 per patient. The 3D regimen, as well as glecaprevir/pibrentasvir and sofosbuvir/velpatasvir/voxilaprevir, presented the highest drug-drug interaction indexes.

Conclusion

Comorbidities and comedications are common in patients with hepatitis C, as are drug-drug interactions. Even when second generation drugs are used, the occurrence of drug-drug interactions still presents a significant risk.

Impact of HCV cure with drug-acting antivirals in the use of concomitant medication and lipid profile: follow-up data 2 years after the sustained virological response

BACKGROUND AND AIM

Patients with chronic hepatitis C (CHC) frequently associated comorbidities and concomitant medication. Sustained virological response (SVR12) has been related to an increase in cholesterol serum levels and in peripheral vascular resistance. Our aim was to evaluate the impact of SVR12 on the use of concomitant medication and serum lipid profile.

METHODS

Prospective study including patients treated with direct-acting antivirals who had achieved the SVR12. Clinical data and concomitant drugs were analysed at baseline and at least 1 year after SVR12. Differences from baseline to follow-up in the concomitant medication were evaluated by Stuart-Maxwell test and lipid profile by Wilcoxon signed-rank test. Patients were categorized according to the increase/decrease in the number of drugs included in each class (Anatomical Therapeutic Chemical classification system).

RESULTS

Two hundred twenty-six patients with SVR12 were included, 73.5% were receiving concomitant drugs (49.6% with antihypertensive effect, 30.5% antacids, 16.4% anti-diabetic drugs, and 7.1% lipid-lowering agents). One year after SVR12, total cholesterol serum levels increased from 161 to 179 mg/dl (P < 0.001) and, after a median time of 25.7 months, the use of lipid-lowering drugs increased from 7.8 to 11.5% (P = 0.009). In addition, we observed a trend to use more antihypertensive drugs in older patients (P = 0.06), especially in those with cirrhosis. Anxiolytics decreased after SVR12 from 13.7 to 10.6% (P = 0.035).

CONCLUSION

CHC cure is associated with a significant increase in cholesterol serum levels and the use of lipid-lowering agents, as well as the use of drugs with antihypertensive effect in older patients.

Drug-Drug Interactions of Newly Approved Direct-Acting Antiviral Agents in Patients with Hepatitis C

Hepatitis C is a major health problem worldwide, frequently resulting in cirrhosis and increasing the risk of hepatocellular carcinoma significantly. In recent years, the advent of direct-acting antivirals (DAAs) has dramatically improved the therapeutic outcomes in hepatitis C patients. In the last two years, several new DAA combinations have been approved for the treatment of the hepatitis C virus (HCV) infection, including elbasvir/grazoprevir, sofosbuvir/velpatasvir, sofosbuvir/velpatasvir/voxilaprevir, and glecaprevir/pibrentasvir. The newly approved DAA regimens may be prescribed with other drugs simultaneously, increasing the potential of pharmacokinetic interactions. Therefore, the knowledge and management of drug-drug interactions (DDIs) with DAAs should be considered a key issue in HCV therapy. This review summarizes researches of DDIs focusing on newly approved DAAs (elbasvir, grazoprevir, velpatasvir, voxilaprevir, glecaprevir, pibrentasvir) for patients undergoing HCV treatment to provide clinical consideration for comedication. With respect to DDIs, newly approved DAA regimens, including elbasvir/grazoprevir, sofosbuvir/velpatasvir, sofosbuvir/velpatasvir/voxilaprevir, and glecaprevir/pibrentasvir, are safely applicable.

Comorbidities and concomitant medications in patients with chronic hepatitis C virus infection receiving second-generation direct-acting antiviral regimens in Belgium: an observational study

Objective

To describe comorbidities and concomitant medications in patients initiating treatment for hepatitis C virus (HCV) infection with direct-acting antiviral (DAA) regimens in Belgium.

Methods

This was a noninterventional, observational, multicenter study of data from patient charts. Adult patients with HCV infection receiving second-generation DAA therapy were included. Comorbidities were assessed at the time of HCV treatment initiation. Concomitant medications were recorded at the time of diagnosis and at treatment initiation. Potential clinically relevant drug-drug interactions (DDIs) were assessed based on information available at www.hep-druginteractions.org. The primary objective was to describe concomitant medication use ; secondary objectives were to describe modifications in concomitant therapies and comorbidities.

Results

405 patients were included. A total of 956 comorbidities were reported by 362 patients (median, 2 ; range, 0-15). The most common comorbidities were hypertension (27.2%) ; HIV coinfection (22.5%), and type 2 diabetes mellitus (14.3%). Overall, 1455 concomitant medications were being taken by 365 patients (90.1% ; median, 3 ; range 0-16). The most common concomitant medications were psycholeptics (28.6%), antiviral agents (24.2%), and medications for acid-related disorders (21.0%) Overall, 74/365 (20.3%) patients receiving a concomitant medication required an adaptation to their concomitant medication. The medications that most frequently required change were drugs for acid-related disorders (n = 14) and antiviral drugs (n = 5) ; those that were most frequently stopped were lipid-modifying drugs (n = 25) and drugs for acid-related disorders (n = 13).

Conclusion

Physicians are aware of the potential for DDIs with DAAs, but improved alignment between clinical practice and theoretical recommendations is required.

Real-world clinical outcomes among individuals with chronic HCV infection in China: CCgenos study

BACKGROUND

This 5-year follow-up of the CCgenos cross-sectional study aimed to observe real-life outcomes in a cohort of 997 Han Chinese patients with chronic HCV infection and to explore the impacts of HCV genotype, patient characteristics and treatment status.

METHODS

Clinical information and centralized HCV RNA measures were collected every 6/3 months for untreated/treated patients. Overall disease progression was defined as ≥1 of: de novo development of cirrhosis, Child-Turcotte-Pugh score increased by ≥2 points (if cirrhosis at baseline), progression to decompensated cirrhosis, hepatocellular carcinoma (HCC), liver transplant or death. Cox regression assessed risk factors for the time from estimated infection to cirrhosis or HCC. Logistic regression assessed risk factors for incidence rates of cirrhosis and overall disease progression.

RESULTS

281 of 514 patients enrolled across China completed 5 years of follow-up. Overall disease progression occurred in 36/364 (9.9%) treated patients and 35/148 (23.6%) untreated patients (odds ratio = 0.35; 95% CI 0.21, 0.59; P<0.0001). Overall disease progression occurred in 6/231 (2.6%) patients achieving sustained virological response at 24 weeks (SVR24) versus 11/82 (13.4%) who did not (P=0.0002). Cirrhosis development was significantly associated with abnormal aspartate aminotransferase (AST), age ≥40 years, body mass index ≥28 kg/m², HCV GT1, platelet count <100×10⁹/l, and AST to platelet ratio index (APRI) ≥2 (multivariate Cox regression, P<0.05). HCC was significantly associated with HCV GT1 and platelet count <100×10⁹/l (multivariate Cox regression, P<0.05).

CONCLUSIONS

Achieving SVR24 significantly reduced the probability of overall disease progression but no significant difference was seen for both cirrhosis and HCC during 5 years of follow-up.

Improving Medication-Related Outcomes in Chronic Liver Disease

Patients with chronic liver disease (CLD) are becoming increasingly complex due to the rising prevalence of multimorbidity and polypharmacy. Medications are often essential to manage the underlying liver disease, complications of cirrhosis and portal hypertension, and comorbidities. However, medication-related problems (MRPs) have been associated with adverse patient outcomes, including hospitalization and mortality. Factors that can contribute to MRPs in people with CLD are variable and often entwined. This narrative literature review discusses key barriers and opportunities to modify risk factors and improve medication-related outcomes for people with CLD.

Review of Clinically Relevant Drug Interactions with Next Generation Hepatitis C Direct-acting Antiviral Agents

In this review, we examine the pharmacokinetics and clinically relevant drug interactions of the newer generation direct-acting antivirals (DAAs) for the treatment of chronic hepatitis C, specifically sofosbuvir/velpatasvir (Epclusa®), sofosbuvir/velpatasvir/voxilaprevir (Vosevi®), glecaprevir/pibrentasvir (Maviret®), and elbasvir/grazoprevir (Zepatier®). We searched MEDLINE (1948-January 2020), Embase (1964-January 2020), Google, and GoogleScholar using the terms pharmacokinetics, drug interaction, drug metabolism, sofosbuvir, velpatasvir, Epclusa, voxilaprevir, Vosevi, glecaprevir, pibrentasvir, Maviret, elbasvir, grazoprevir, and Zepatier, from inception to January 13, 2020. The search was limited to randomized controlled trials, in vitro studies, prospective and retrospective human studies, drug monographs, abstracts, and conference proceedings. All relevant published literature on pharmacokinetic and pharmacodynamic interactions involving DAAs were reviewed and the data extracted. Numerous clinically relevant drug-drug interactions (DDIs) were identified with the newer generation DAAs and commonly prescribed drugs. NS3/4A protease inhibitors are more likely to be involved in DDIs, followed by NS5A inhibitors and NS5B polymerase inhibitor. The majority of clinically relevant DDIs are predictable, according to known pharmacokinetic, pharmacodynamics, and physicochemical properties of DAAs; however, in select cases, unpredictable DDIs do occur. As expected, many drug interactions exist between newer generation DAAs and commonly prescribed medications. While the majority of clinically relevant interactions are predictable, many require therapeutic dose adjustment or careful selection of non-interacting drugs. In select cases, severe and unpredictable drug interactions can occur. Clinicians should consult hepatitis C virus pharmacotherapy experts and tertiary drug interaction resources when initiating DAA therapy in patients taking other medications.

Comparing drug interaction frequencies of various hepatitis C treatment regimens among monoinfected patients

INTRODUCTION AND OBJECTIVES

Four regimens are recommended for treating hepatitis C (HCV) genotype 1 infection. Study aims were to (1) compare frequencies of contraindicated drug interactions (XDDIs) when each HCV regimen is added to medication profiles of HCV-monoinfected patients, (2) quantify the proportion of patients with XDDIs to all four regimens and (3) determine covariates independently associated with having a XDDI to all four regimens.

MATERIALS AND METHODS

A cross-sectional study was performed within Upstate New York Veterans Healthcare Administration.

INCLUSION CRITERIA

(1) age ≥18 years, (2) HCV monoinfection and (3) available medication list. Data extracted were: demographics, comorbidities, and medication list. Primary outcome was XDDIs involving patient's home medications and each HCV regimen. University of Liverpool drug interaction website was used to define XDDIs. Two-way comparisons of regimens were performed using McNemar's test where p<0.0083 was considered statistically significant. Multivariate regression analyses were performed to determine predictors.

RESULTS

Of the 4047 subjects, mean±standard deviation age was 59.8±7.6. Median (interquartile range) number of medications used was 7 [4-11]. Frequencies of XDDIs after the addition of each regimen ranged from 2.8% to 17.8% and were mostly statistically different from one another. There were 95 (2.3%) patients with XDDIs to all four regimens. Predictors of having XDDIs to all four regimens were ≥6 medications and HCV infection ≥10 years.

CONCLUSION

The frequencies of XDDIs varied between HCV regimens. Number of medications and duration of HCV infection were predictors of having XDDIs to all four regimens.

Cardiovascular Risk Management and Hepatitis C: Combining Drugs

Direct-acting antivirals (DAAs) are known victims (substrate) and perpetrators (cause) of drug–drug interactions (DDIs). These DAAs are used for the treatment of hepatitis C virus (HCV) infections and are highly effective drugs. Drugs used for cardiovascular risk management are frequently used by HCV-infected patients, whom also are treated with DAAs. Therefore, the aim of this review was to describe DDIs between cardiovascular drugs (CVDs) and DAAs. An extensive literature search was performed containing search terms for the marketed DAAs and CVDs (β-blocking agents, ACE inhibitors, angiotensin II antagonists, renin inhibitors, diuretics, calcium channel blockers, statins/ezetimibe, fibrates, platelet aggregation inhibitors, vitamin K antagonists, heparins, direct Xa inhibitors, nitrates, amiodarone, and digoxin). In particular, the drug labels from the European Medicines Agency and the US Food and Drug Administration were used. A main finding of this review is that CVDs are mostly victims of DDIs with DAAs. Therefore, when possible, monitoring of pharmacodynamics is recommended when coadministering these drugs with DAAs. Nevertheless, it is sometimes better to discontinue a drug on a temporary basis (statins, ezetimide). The DAAs are victims of DDIs in combination with bisoprolol, carvedilol, labetalol, verapamil, and gemfibrozil. Despite there are many DDIs predicted in this review, most of these DDIs can be managed by monitoring the efficacy and toxicity of the victim drug or by switching to another CVD/DAA.

Drug-drug interactions between direct-acting antivirals and statins in the treatment of chronic hepatitis C

As the first line of treatment for hepatitis C virus (HCV) infection, direct-acting antivirals (DAAs) have greater efficacy and fewer adverse effects than other treatments; however, drug-drug interactions (DDIs) must be avoided when used in combination with other medications, such as statins. HCV patients are mostly in the need for polypharmacy, particularly the comedication of DAAs and cardiovascular drugs such as statins. This poses a risk of pharmacokinetic interactions between the two classes of drugs that may lead to severe myopathy or even rhabdomyolysis. Therefore, evaluating the severity of the DDIs and managing them is important. A multidisciplinary team-based model of care for HCV patients receiving DAAs can review the pharmacology profiles of other drugs for relevant DDIs with the DAAs, before prescription. Such a model can also follow the patients through the therapeutic cycle to make sure that their medical regimen is safe and effective. This article reviews the comedication rate and DDI-prevalence in HCV patients receiving statins along with the DAAs, details the mechanisms involved, gives recommendations for management, and shares our experience with a multidisciplinary team-based care program for the treatment of HCV patients.

Barriers to treatment of chronic hepatitis C with direct acting antivirals in an urban clinic

INTRODUCTION AND AIM

Direct-acting antiviral (DAA) agents are highly effective for treatment of chronic hepatitis C virus (HCV) yet access to treatment remains a serious challenge. The aim of this study was to identify barriers to treatment initiation with DAA-containing regimens in an urban clinic setting.

MATERIALS AND METHODS

A retrospective cohort of all chronic HCV patients seen in an urban academic practice in Jacksonville, FL, USA from 1/2014 to 1/2017 was analyzed. Baseline characteristics were recorded and a review of medical records was performed to identify barriers to treatment initiation and overall success rates.

RESULTS

Two-hundred and forty patients with chronic HCV were analyzed. Fifty-six percent of patients were African-American and 63% were insured through Medicaid/county programs or uninsured. Sixty-nine percent had barriers to initiating antiviral therapy categorized as psychosocial (n=112), provider (n=26), medical (n=20), and insurance-related factors (n=7). The most commonly encountered psychosocial barriers included failure to keep appointments (79/240, 33%), active substance abuse (18/240, 8%), and failure to obtain laboratory testing (11/240, 5%). Overall, only 27% of patients evaluated were initiated on DAA-containing regimens with 18% reaching SVR12 within the 36-month study period.

CONCLUSION

In conclusion, only 27% of patients who presented to an urban academic practice with chronic HCV received DAA-containing regimens over a 36-month period. Psychosocial issues were the major barriers to antiviral therapy. These findings illustrate the need for an integrated approach that addresses psychosocial factors as well as comorbidities and adherence to care in order to increase rates of HCV treatment in at risk patients.

Limited drug-drug interaction of elbasvir/grazoprevir for chronic hepatitis C

BACKGROUND/PURPOSE

The assessment of drug-drug interaction (DDI) is important not only for safety but also for maintaining the efficacy of direct acting antivirals in chronic hepatitis C (CHC). This study aims to evaluate DDI before and during elbasvir/grazoprevir (EBR/GZR) treatment.

METHODS

CHC patients who treated with EBR/GZR in five hospitals were enrolled. The patients' demographic data, comorbidities, concomitant medications taken before and during EBR/GZR were recorded. DDI was evaluated using a tool from the HEP Drug Interactions (www.hep-druginteractions.org) website. In addition to the evaluation of DDI for EBR/GZR, the virtual DDI of ledipasvir/sofosbuvir (LDV/SOF), sofosbuvir/velpatasvir (SOF/VEL) and glecaprevir/pibrentasvir (GLE/PIB) were evaluated. Degrees of DDI were classified as "do not co-administer", "potential interaction", and "potentially weak interaction".

RESULTS

A total of 460 patients were enrolled. At baseline, 80.1% of patients had one or more comorbidities and 72.8% took one or more medications. Cardiovascular diseases (43.9%), gastrointestinal diseases (37.4%), and metabolic diseases (36.7%) were the three most common comorbidities. The prevalence of DDI before EBR/GZR treatment was 12.8% (59 patients). Among the same population, the prevalence of virtual DDI of SOF/VEL, GLE/PIB, and LDV/SOF were 38.5% (179 patients), 48.8% (220 patients), and 57.0% (262 patients), respectively. During EBR/GZR treatment, 167 patients (36.3%) took newly prescribed medications. One patient (0.2%) and seven patients (1/5%) exhibited do-not-co-administer and potential interaction with EBR/GZR, respectively.

CONCLUSION

DDI was limited in treatment with EBR/GZR. DDI can occur upon the administering of a new medication during antiviral treatment and attention should be paid to it.

TRIAL REGISTRATION NUMBER

NCT03706222.

Effect of comedication on ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin therapy in chronic hepatitis C - a real-world study

Aim of the study

This multicentre study aimed to examine the actual risk for drug-drug interactions in a cohort of Polish patients, and their impact on antiviral therapy.

Material and methods

Concomitant medications were analyzed in hepatitis C virus (HCV)-infected patients treated with still valuable therapy with OBV/PTV/r ± DSV ± RBV. An established online tool (http://www.hep-druginteractions.org/) was used to assess potential drug interactions. To assess the impact of comedications on virologic outcomes, HCV RNA levels were measured at given time points during and after the treatment. The results were compared between subgroups depending on the number of drugs used.

Results

Among the 209 patients included in this multicentre study, concomitant medications were taken by 140 (67.0%) patients. Modification of treatment due to expected interactions was required in 33 (15.8%) patients, of whom nine (4.3%) had at least one comedication replaced or discontinued. Sustained virologic response rates ranged from 95.1% to 100.0%, and were lowest in patients taking one to five comedications who were null-responders to pegylated interferon or cirrhotic.

Conclusions

Although most HCV-infected patients received concomitant medications, only some required treatment modification. OBV/PTV/r ± DSV ± RBV was effective in all subgroups, irrespective of the number of comedications taken. Multimorbidity and polypharmacy in patients with chronic hepatitis C should not discourage the decision to initiate antiviral therapy, although caution should be exercised for potential drug-drug interactions.

Prevalence of the potential drug-drug interactions between pangenotypic direct-acting antivirals and the concomitant medications associated with patients with chronic hepatitis C virus infection in Spain

OBJECTIVE

To determine the comorbidity and potential for drug-drug interactions (DDIs) among pangenotypic direct-acting-antivirals (pDAAs) and the concomitant medications associated with chronic hepatitis C (CHC) patients in routine clinical practice in Spain.

METHODS

Retrospective observational study. Included patients were ≥18 years, diagnosed with CHC, on antiviral treatment and required medical attention during 2017. Two groups were differentiated according to age ranges (<50 and ≥50 years). The variables collected were: age, gender, general/specific comorbidity, concomitant medication and potential DDIs (www.hep-druginteractions.org). The pDAAs analysed were: a) Sofosbuvir/Velpatasvir (SOF/VEL), b) Glecaprevir/Pibrentasvir (GLE/PIB) and c) Sofosbuvir/Velpatasvir/Voxilaprevir (SOF/VEL/VOX). Bivariate statistical analysis, P<.05.

RESULTS

3,430 patients with a mean age of 56.9 years and 60.3% males were enrolled. The average Charlson index was 0.8. Age range distribution: 18-49 years (28.9%) and ≥50 years (71.1%). The average number of medications per patient/year was 3.1 (SD 2.6). The total percentage of potential DDIs was: 8.6% minor DDIs, 40.5% clinically significant DDIs and 10.0% contraindicated medication. These DDIs were greater in patients ≥50 years (8.6%, 43.8% and 12.4%, respectively, P<.001). For all ages, SOF/VEL showed a lower percentage of: minor interactions (1.3% vs. 6.6% and 5.9%, P<.001); clinically significant interactions (53.4%, vs. 77.4% and 66.3%, P<.001) and contraindicated medication (1.7% vs. 8.3% and 10.7%, P<.001) compared to GLE/PIB and SOF/VEL/VOX, respectively.

CONCLUSIONS

Patients with CHC present high comorbidity and concomitant medication use, particularly elderly patients, thus implying a greater exposure to potential DDIs. Although the DDI rate was considerable with the three combinations analysed, SOF/VEL showed a lower number of clinically significant interactions.

HCV-infected individuals have higher prevalence of comorbidity and multimorbidity: a retrospective cohort study

Background

Almost 1% of Canadians are hepatitis C (HCV)-infected. The liver-specific complications of HCV are established but the extra-hepatic comorbidity, multimorbidity, and its relationship with HCV treatment, is less well known. We describe the morbidity burden for people with HCV and the relationship between multimorbidity and HCV treatment uptake and cure in the pre- and post-direct acting antiviral (DAA) era.

Methods

We linked adults with HCV at The Ottawa Hospital Viral Hepatitis Program as of April 1, 2017 to provincial health administrative data and matched on age and sex to 5 Ottawa-area residents for comparison. We used validated algorithms to identify the prevalence of mental and physical health comorbidities, as well as multimorbidity (2+ comorbidities). We calculated direct age- and sex-standardized rates of comorbidity and comparisons were made by interferon-based and interferon-free, DAA HCV treatments.

Results

The mean age of the study population was 54.5 years (SD 11.4), 65% were male. Among those with HCV, 4% were HIV co-infected, 26% had liver cirrhosis, 47% received DAA treatment, and 57% were cured of HCV. After accounting for age and sex differences, the HCV group had greater multimorbidity (prevalence ratio (PR) 1.38, 95% confidence interval (CI) 1.20 to 1.58) and physical-mental health multimorbidity (PR 2.71, 95% CI 2.29–3.20) compared to the general population. Specifically, prevalence ratios for people with HCV were significantly higher for diabetes, renal failure, cancer, asthma, chronic obstructive pulmonary disease, substance use disorder, mood and anxiety disorders and liver failure. HCV treatment and cure were not associated with multimorbidity, but treatment prevalence was significantly lower among middle-aged individuals with substance use disorders despite no differences in prevalence of cure among those treated.

Conclusion

People with HCV have a higher prevalence of comorbidity and multimorbidity compared to the general population. While HCV treatment was not associated with multimorbidity, people with substance use disorder were less likely to be treated. Our results point to the need for integrated, comprehensive models of care delivery for people with HCV.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4315-6) contains supplementary material, which is available to authorized users.

Clinical and Economic Burden of Patients with Chronic Hepatitis C with Versus Without Antiviral Treatment in Japan: An Observational Cohort Study Using Hospital Claims Data

Introduction

Japan has one of the highest prevalence rate of chronic hepatitis C (CHC) in the industrialized world. However, the burden of CHC treatment is poorly understood. Thus, the healthcare resource utilization and costs of treated versus untreated patients, and patients with early versus delayed treatment initiation, were assessed in Japan.

Methods

Adult patients with ≥ 2 CHC diagnoses were identified from the Medical Data Vision hospital claims database (1 April 2008–31 May 2016). The presence or absence of antiviral treatment claims was used to form the treated and untreated cohorts, respectively. Among treated patients, the presence of a cirrhosis-related diagnosis was used as an indicator of delayed treatment. The index date was defined as the date of the first antiviral claim for treated patients and randomized to any date with a medical visit for untreated patients. Annualized total healthcare costs and costs associated with hepatic manifestations (HMs) or extrahepatic manifestations (EHMs) were evaluated from the index date to the last observed medical visit.

Results

Of 100,125 patients with CHC, 12,984 were treated (early: 8104, delayed: 4880) and 87,141 were untreated. After adjusting for covariates, untreated patients had ¥613,034 ($5456 USD; ¥1 = $0.0089) higher annual medical costs compared with treated patients (P < 0.001), a difference driven by higher inpatient costs. Between 65% (treated patients) and 70% (untreated patients) of medical costs were EHM-related and between 14% (untreated patients) and 15% (treated patients) were HM-related. Patients in the delayed treatment cohort had ¥114,347 ($1018) higher annual medical costs (P < 0.001) versus those in the early treatment cohort. About 95% of these costs were EHM-related, and 64% were HM-related.

Conclusion

Withholding or delaying antiviral treatment initiation for Japanese patients with CHC increases the clinical and economic burden associated with HMs and EHMs.

Funding

AbbVie.

Enabling an HCV Treatment Revolution and the Frontiers of Solid Solution Formulation

The discovery and development of small molecule direct acting antiviral (DAA) drugs has revolutionized the treatment of Hepatitis C virus infection. Formulations based on solid solution technology have enabled the oral absorption of the majority of commercial DAA products starting with the approval of telaprevir in 2011. A particularly important class of DAA drugs are those targeting nonstructural protein 5A. In addition to simply promoting the oral absorption of nonstructural protein 5A compounds, solid solutions have been used within this class of compounds to mitigate changes in absorption caused by variations in food and stomach pH. This commentary reviews the formulation and biopharmaceutical aspects of the solid solutions used to enable the recent revolution in Hepatitis C virus infection treatment.

Drug-Drug Interactions Potential of Direct-Acting Antivirals for the treatment of Chronic Hepatitis C Virus infection

The advent of direct-acting antiviral agents (DAAs) has transformed the hepatitis C virus (HCV) therapeutic landscape in terms of efficacy and safety, with a cure rate of more than 90%. However, an important potential for drug-drug interactions (DDIs) is expected with these combinations, particularly in patients with other comorbidities (e.g. HIV co-infection, cardiovascular diseases). Each DAA can be a substrate, an inhibitor and/or an inducer of metabolic enzymes and drug efflux transporters. DAAs can act as both victims and perpetrators of DDIs and can sometimes increase the risk and/or intensity of side effects or limit the efficacy of treatment. Therefore, knowledge and management of DDIs with DAAs should be considered a key issue of HCV therapy. This review describes the pharmacokinetic profile of currently used and recommended DAA regimens and summarizes available data regarding DDIs to optimize HCV treatment in clinical practice.

Drug-Drug Interactions in Hepatitis Patients: Do these Interactions Matter in Clinical Perspectives?

INTRODUCTION AND AIM

Hepatitis patients usually present with comorbidities and polypharmacy which increases risk of potential drug-drug interactions (pDDIs). We explored frequency, levels, predictors, and clinical relevance of pDDIs in hospitalized hepatitis patients.

MATERIAL AND METHODS

Retrospective cohort study was used. Clinical profiles of 413 hepatitis patients were reviewed for pDDIs using Micromedex-DrugReax. Frequency, levels and clinical relevance of pDDIs were reported. Logistic regression analysis was used to calculate odds-ratios for predictors.

RESULTS

Of total 413 patients, pDDIs were reported in 55.2%. Major-pDDIs were found in 35% patients. Total 660 pDDIs were identified, of which, 304 (46%) were of major-severity and 299 (45%) of moderateseverity. Patient's profiles of top-10 major-pDDIs were presented with signs/symptoms such as fever, hepatomegaly, anorexia, jaundice, hypertension, tachycardia, bradycardia, & pedal edema; and abnormalities in labs such as electrolytes-level, alanine aminotransferase, blood urea nitrogen, bilirubin-level, & serum creatinine. Significant association was observed for the presence of pDDIs with > 9 prescribed medicines (p < 0.001), hospitalization of > 5 days (p = 0.03), and stroke as comorbidity (p = 0.05). Moreover, odds of exposure to major-pDDIs were significantly higher in patients taking > 9 prescribed medicines (p < 0.001), hospitalization of > 5 days (p = 0.002), and stroke as comorbidity (p = 0.002).

CONCLUSION

We observed hepatitis patients presented with a considerable number of clinically relevant pDDIs. Attention should be given to widespread major-pDDIs and their potential adverse outcomes. Clinically relevant parameters, such as labs and signs/symptoms should be monitored particularly in high risk patients having polypharmacy, prolong hospitalization, and stroke as comorbidity.

A Multi-Fidelity Rollout Algorithm for Dynamic Resource Allocation in Population Disease Management

Dynamic resource allocation for prevention, screening, and treatment interventions in population disease management has received much attention in recent years due to excessive healthcare costs. In this paper, our goal is to design a model and an efficient algorithm to optimize sequential intervention policies under resource constraints to improve population health outcomes. We consider a discrete-time finite-horizon budget allocation problem with disease progression within a closed birth-cohort population. To address the computational challenges associated with large-state and multiple-period dynamic decision-making problems, we propose a low-fidelity approximation that preserves the population dynamics under a stationary policy. To improve the healthcare interventions in terms of population health outcomes, we then embed the low-fidelity approximation into a high-fidelity optimization model to efficiently identify a good non-stationary sequential intervention policy. Our approach is illustrated by a numerical example of screening and treatment policy implementation for chronic hepatitis C virus (HCV) infection over a budget planning period. We numerically compare our Multi-Fidelity Rollout Algorithm (MF-RA) to a grid search approach and demonstrate the similarity of sequential policy trends and closeness of overall health outcomes measured by quality-adjusted life-years (QALYs) and the total number of individuals that undergo screening and treatment for different annual budgets and birth-cohorts. We also show how our approach scales well to problems with high dimensionality due to many decision periods by studying time to elimination of HCV.

Pharmacokinetic Interactions and Safety of Coadministration of Glecaprevir and Pibrentasvir in Healthy Volunteers

BACKGROUND AND OBJECTIVE

Glecaprevir and pibrentasvir are pangenotypic direct-acting antiviral agents for the treatment of chronic hepatitis C virus infection. The aim of the present study was to evaluate the drug-drug interaction and safety of glecaprevir and pibrentasvir coadministration in healthy volunteers.

METHODS

In this open-label, randomized, multiple-dose, Phase 1 study in 72 subjects, glecaprevir (100-1200 mg once daily) and pibrentasvir (40-200 mg once daily) were administered alone for 7 days and then in combination for another 7 days. Intensive blood sampling was performed on Days 1, 7, 8, and 14, and pharmacokinetic interactions were assessed using a repeated measures analysis of glecaprevir and pibrentasvir maximum plasma concentration (C _max) and area under the curve (AUC).

RESULTS

Coadministration of glecaprevir 400 mg increased pibrentasvir 120 and 40 mg steady-state C _max and AUC values to 2.9-6.3-fold, and coadministration of glecaprevir 700 mg increased pibrentasvir 160 mg steady-state C _max and AUC₂₄ values to up to sevenfold of the values when pibrentasvir was administered alone. Glecaprevir C _max and AUC values during coadministration were less than 1.5-fold of the values when glecaprevir was administered alone. The combination of glecaprevir and pibrentasvir at doses up to 400 mg was well tolerated by the healthy subjects in this study. High glecaprevir exposures at 700 and 1200 mg were associated with grade 2/3 elevations in alanine aminotransferase, aspartate aminotransferase, and/or bilirubin.

CONCLUSIONS

Coadministration of pibrentasvir 120 mg with glecaprevir doses up to 400 mg resulted in increases in pibrentasvir exposures without significant changes in glecaprevir exposures in the absence of any clinically significant laboratory abnormalities.

Comorbidities and co-medications in populations with and without chronic hepatitis C virus infection in Japan between 2015 and 2016

BACKGROUND

Direct-acting anti-viral agents have improved the treatment of chronic hepatitis C virus (HCV) infection, but this treatment is challenging for patients using co-medications because of potential drug-drug interactions. This study aimed to examine the comorbidities and co-medications of Japanese chronic HCV patients by age group, compared with a non-HCV patient population.

METHODS

This was a retrospective observational study using a hospital-based medical claims database. We extracted data of patients with chronic HCV aged ≥18 years, and age-, sex-, and hospital-matched patients without HCV, for the period from January 2015 to November 2016, and then examined chronic comorbidities, long-term co-medications, and medications prescribed at least once during the study period.

RESULTS

We analysed data from 128,967 chronic HCV patients and 515,868 non-HCV patients. The median age was 70 years, and 51.0% of patients were male. More chronic HCV patients than non-HCV patients (70.5% vs. 47.1%) had at least one comorbidity, and older patients had more comorbidities than younger patients. The most common comorbidities in chronic HCV patients were diseases of oesophagus, stomach and duodenum (41.7%), followed by hypertensive diseases (31.4%). Chronic HCV patients used co-medications more commonly than non-HCV patients, and older patients used more co-medications. The most common long-term co-medications in chronic HCV patients were proton pump inhibitors (14.0%), which were prescribed to 31.9% of chronic HCV patients at least once during the study period.

CONCLUSIONS

Patients with chronic HCV in Japan had more comorbidities than patients without chronic HCV regardless of age. Particularly older patients, who constitute the majority of the HCV patient population in Japan, commonly had multiple comorbidities and used co-medications. To optimise HCV treatment, physicians need to know the exact medication profiles of patients and take appropriate action to manage drug-drug interactions.

Comorbidity, concomitant medication, use of resources and healthcare costs associated with chronic hepatitis C virus carriers in Spain

OBJECTIVES

To assess the comorbidity, concomitant medications, healthcare resource use and healthcare costs of chronic hepatitis C virus patients in the Spanish population.

PATIENTS AND METHODS

Retrospective, observational, non-interventional study. Patients included were≥18 years of age who accessed medical care between 2010-2013. Patients were divided into 2 groups based on the presence or absence of liver cirrhosis. The follow-up period was 12 months. Main assessment criteria included general comorbidity level (determined by the resource utilisation band score) and prevalence of specific comorbidities, concomitant medications, healthcare resource use and healthcare costs. Statistical analysis was performed using regression models and ANCOVA, P<.05.

RESULTS

One thousand fifty-five patients were enrolled, the mean age was 57.9 years and 55.5% were male. A percentage of 43.5 of patients had a moderate level of comorbidity according to the resource utilisation band score. The mean time from diagnosis was 18.1 years and 7.5% of the patients died during the follow-up period. The most common comorbidities were dyslipidaemia (40.3%), hypertension (40.1%) and generalised pain (38.1%). Cirrhosis was associated with cardiovascular events (OR 3.8), organ failures (OR 2.2), alcoholism (OR 2.1), diabetes (OR 1.2) and age (OR 1.2); P<.05. The most commonly used medications were anti-infectives (67.8%) and nervous system medications (66.8%). The mean total cost per patient was 3,198€ (71.5% healthcare costs, 28.5% indirect/non-healthcare costs). In the corrected model, the total costs per patient-year were 2,211€ for those without cirrhosis and 7,641€ for patients with cirrhosis; P<.001.

CONCLUSIONS

Chronic hepatitis C virus patients are associated with a high level of comorbidity and the use of concomitant medications, especially in patients with liver cirrhosis. Chronic hepatitis C virus infection represents a substantial economic burden on the Spanish National Health System.

Drug-Drug Interactions Between the Anti-Hepatitis C Virus 3D Regimen of Ombitasvir, Paritaprevir/Ritonavir, and Dasabuvir and Eight Commonly Used Medications in Healthy Volunteers

Background and Aims

The three direct-acting antiviral regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir (3D regimen) is approved for treatment of hepatitis C virus (HCV) genotype 1 infection. Drug–drug interaction (DDI) studies of the 3D regimen and commonly used medications were conducted in healthy volunteers to provide information on coadministering these medications with or without dose adjustments.

Methods

Three phase I studies evaluated DDIs between the 3D regimen (ombitasvir/paritaprevir/ritonavir 25/150/100 mg once daily + dasabuvir 250 mg twice daily) and hydrocodone bitartrate/acetaminophen (5/300 mg), metformin hydrochloride (500 mg), diazepam (2 mg), cyclobenzaprine hydrochloride (5 mg), carisoprodol (250 mg), or sulfamethoxazole/trimethoprim (SMZ/TMP) (800/160 mg twice daily), all administered orally. DDI magnitude was determined using geometric mean ratios and 90 % confidence intervals for the maximum plasma concentration (C_max) and area under the plasma concentration–time curve (AUC).

Results

Changes in exposures (C_max and AUC geometric mean ratios) of acetaminophen, metformin, sulfamethoxazole, trimethoprim, and diazepam were ≤25 % upon coadministration with the 3D regimen. The C_max and AUC of nordiazepam, an active metabolite of diazepam, increased by 10 % and decreased by 44 %, respectively. Exposures of cyclobenzaprine and carisoprodol decreased by ≤40 and ≤46 %, respectively, whereas exposures of hydrocodone increased up to 90 %. Ombitasvir, paritaprevir, ritonavir, and dasabuvir exposures changed by ≤25 %, except for a 37 % decrease in paritaprevir C_max with metformin and a 33 % increase in dasabuvir AUC with SMZ/TMP.

Conclusions

Acetaminophen, metformin, sulfamethoxazole, and trimethoprim can be coadministered with the 3D regimen without dose adjustment. Higher doses may be needed for diazepam, cyclobenzaprine, and carisoprodol based on clinical monitoring. A 50 % lower dose and/or clinical monitoring should be considered for hydrocodone. No dose adjustment is necessary for the 3D regimen.

Concomitant proton pump inhibitor use does not reduce the efficacy of elbasvir/grazoprevir: A pooled analysis of 1,322 patients with hepatitis C infection

Concomitant proton pump inhibitor (PPI) use reduces plasma concentrations of certain nonstructural protein 5A inhibitors, which are key components of modern hepatitis C infection (HCV) treatments. These reduced concentrations may decrease efficacy, leading to challenging treatment failures due to the development of resistance-associated substitutions. This post-hoc analysis assessed 12-week sustained viral response (SVR12) and pharmacokinetics of fixed-dose combination elbasvir/grazoprevir (EBR/GZR) in patients with HCV infection and self-reported PPI use. Data were derived from six phase 3 EBR/GZR trials with treatment-naive or treatment-experienced genotype 1- or 4-infected patients, with or without compensated cirrhosis. Baseline PPI use was defined as ≥7 consecutive days of use between study days -7 and 7. Bivariate analyses assessed PPI use and factors associated with SVR12 with sex, age (continuous and dichotomous), cirrhosis status, prior treatment status, baseline HCV RNA (continuous and dichotomous), HCV genotype, and baseline resistance-associated substitutions as variables in the models. Overall, 12% (162/1,322) of EBR/GZR-treated patients reported baseline PPI use. Of those, 96% achieved SVR12. In patients without PPI use, 97% achieved SVR12. PPI use was not a predictive factor in achieving SVR12 based on a univariate analysis (P = 0.188). In the bivariate models, none of the interaction terms involving PPI use were statistically significant. There was no significant effect of PPI usage, regardless of adjustment for considered factors. The estimated area under the curve and maximum concentration values for EBR were comparable among patients with and without reported PPI use. Conclusion: These results demonstrate that PPI use with EBR/GZR had no clinically significant effect on SVR12 rates in genotype 1/4-infected patients with or without compensated cirrhosis. (clinicaltrials.gov identifiers: NCT02092350, NCT02105467, NCT02105662, NCT02105688, NCT02105701, NCT02358044) (Hepatology Communications 2017;1:757-764).

Changes in renal function indices in cirrhotic chronic hepatitis C patients treated with sofosbuvir-containing regimens

This study aimed to explore changes in hepatic and renal function indices in chronic hepatitis C (CHC) patients treated with direct-acting antivirals (DAAs). Forty-three CHC patients treated with sofosbuvir (SOF)-containing regimens were enrolled. At the end of treatment, the estimated glomerular filtration rate (eGFR) level was significantly decreased and the serum creatinine (Scr) and uric acid (UA) levels were significantly increased compared with baseline levels (eGFR: 86.7 ± 20.4 vs 80.5 ± 21.3, P₀₁ = 0.005; Scr: 83.9 ± 19.1 vs 89.6 ± 21.1, P₀₁ < 0.001; UA: 323.7± 86.2 vs 358.5 ± 93.2, P₀₁ < 0.001); no significant improvements were observed at 24 w post-treatment (eGFR: 86.7 ± 20.4 vs 81.4 ± 18.6, P₀₂ = 0.013; Scr: 83.6 ± 17.9 vs 87.9 ± 18.3, P₀₂ = 0.014; UA: 320.8 ± 76.3 vs 349.3 ± 91.0, P₀₂ = 0.004). When the patients were grouped by liver conditions, non-cirrhotic patients and cirrhotic patients had decreased eGFR levels and increased Scr levels at the end of treatment; at 24 w post-treatment, the eGFR and Scr levels were significantly improved in non-cirrhotic patients (88.4 ± 21.7 vs 83.8 ± 18.5, P₀₂ = 0.142; 84.4 ± 20.4 vs 87.0 ± 16.9, P₀₂ = 0.088), while no obvious improvements were observed in cirrhotic patients (84.3 ± 18.7 vs 78.1 ± 18.6, P₀₂ = 0.002; 83.2 ± 17.7 vs 89.2 ± 20.6, P₀₂ = 0.006). Clinical physicians should closely monitor renal function in patients treated with SOF-containing regimens, especially in cirrhotic patients.

Prioritization for interferon-free regimens and potential drug interactions of current direct-acting anti-hepatitis C agents in routine clinical practice

BACKGROUND

We determined the proportions of patients with chronic hepatitis C (CHC) in association with possible prioritized indications for interferon-free regimens and the use of co-medications with potential drug-drug interactions (DDIs).

METHODS

Five hundred consecutive mono-infected CHC patients seen in 2015 at 5 Greek centers were included. Priorities for interferon-free regimens were based on liver disease severity, contraindication(s) for interferon and prior interferon-treatment failure. All co-medications were classified into those with no DDIs/no clear data for DDIs, potential DDIs, and contraindication due to DDI for each agent, according to the HEP Drug Interaction Checker.

RESULTS

Of the 500 patients, 1% had undergone liver transplantation, whereas 6.6% had decompensated cirrhosis, 21.8% F4, 17.1% F3, 10.4% F2, and 34.8% F0-1 fibrosis. Contraindications for interferon were present in 38.5% of non-transplant patients with compensated liver disease. The probability of contraindications/potential DDIs was greater for boceprevir/telaprevir and ombitasvir/paritaprevir/ritonavir±dasabuvir, compared to all other agents (P<0.001), and least for sofosbuvir (P<0.05). Contraindications/potential DDIs were more frequently present in patients ≥50 than <50 years old (P≤0.034), and more common in F3-4 than F0-2, and F4 than F0-3 fibrosis (P≤0.019) for all direct-acting antivirals (DAAs).

CONCLUSIONS

The expansion of the criteria for prioritization of interferon-free regimens from cirrhosis to F3 and perhaps F2 fibrosis will increase the proportion of patients with DAA access by only 10-15% and 10%, respectively. A potential for DDIs is frequently present with protease inhibitors, but also exists with other DAAs. The probability of DDIs is higher in patients with priority for DAAs, including those who have advanced liver disease and are usually of older age.

No Pharmacokinetic Interaction Between the Hepatitis C Virus Inhibitors Elbasvir/Grazoprevir and Famotidine or Pantoprazole

Use of agents to suppress gastric acid secretion is common among patients with hepatitis C virus (HCV) infection. The aims of this open‐label, three‐period, fixed‐sequence study were to evaluate the effect of famotidine and pantoprazole on the pharmacokinetics and safety of elbasvir/grazoprevir fixed‐dose combination (FDC) in 16 healthy subjects. Elbasvir and grazoprevir each exhibited similar pharmacokinetics following single‐dose administration of elbasvir/grazoprevir with or without famotidine or pantoprazole. Geometric mean ratios (GMRs) of grazoprevir AUC(0,∞), C_max, and C₂₄ (elbasvir/grazoprevir + famotidine or elbasvir/grazoprevir + pantoprazole vs. elbasvir/grazoprevir) ranged from 0.89–1.17. Similarly, GMRs of elbasvir AUC(0,∞), C_max, and C₂₄ (elbasvir/grazoprevir + famotidine or elbasvir/grazoprevir + pantoprazole vs. elbasvir/grazoprevir) ranged from 1.02–1.11. These results indicate that gastric acid‐reducing agents do not modify the pharmacokinetics of elbasvir or grazoprevir in a clinically relevant manner and may be coadministered with elbasvir/grazoprevir in HCV‐infected patients without restriction.

Clinically Significant Drug-Drug Interactions Between Hepatitis C Virus and HIV Treatments

The potential for drug-drug interactions is an important consideration in the treatment of HIV/hepatitis C virus (HCV) coinfection. Regimens for HCV genotype 1 infection are discussed in the context of an individual on stable antiretroviral therapy, to determine which HCV treatments may be initiated without requiring a change in antiretroviral regimen or an increase in monitoring for potential drug-drug interactions. The effects of potential interactions between HCV drugs and other therapeutic classes of drugs are also discussed. This article summarizes a presentation by Jennifer J. Kiser, PharmD, at the IAS-USA continuing education program, Improving the Management of HIV Disease, held in Los Angeles, California, in April 2016.

Managing drug-drug interactions with new direct-acting antiviral agents in chronic hepatitis C

Several direct-acting antiviral agents (DAAs) have marketing authorization in Europe and in the USA and have changed the landscape of hepatitis C treatment: each DAA has its own metabolism and drug-drug interactions (DDIs), and managing them is a challenge. To compile the pharmacokinetics and DDI data of the new DAA and to provide a guide for management of DDI. An indexed MEDLINE search was conducted using the keywords: DAA, hepatitis C, simeprevir, daclatasvir, ledipasvir, sofosbuvir, 3D regimen (paritaprevir/ritonavir, ombitasvir, dasabuvir), DDI and pharmacokinetics. Data were also collected from hepatology, and infectious disease and clinical pharmacology conferences abstracts. Food can play a role in the absorption of DAAs. Most of the interactions are linked to metabolism (cytochrome P450-3 A4 [CYP3A4]) or hepatic and/or intestinal transporters (organic anion-transporting polypeptide and P-glycoprotein [P-gp]). To a lesser extent other pathways can be involved such as breast cancer resistance protein transporter or UDP-glucuronosyltransferase metabolism. DDI are more likely to occur with 3D regimen, daclatasvir, simeprevir and ledipasvir, as they are all both substrates and inhibitors of P-gp and/or CYP3A4, than with sofosbuvir. They can increase concentrations of coadministered drugs and their concentrations may be influenced by P-gp or CYP3A4 inducers or inhibitors. Overdosage or low dosage can be encountered with potent inducers or inhibitors of CYP3A4 or drugs with a narrow therapeutic range. The key to interpret DDI data is a good understanding of the pharmacokinetic profiles of the drugs involved. Their ability to inhibit CYP450-3A4 and transporters (hepatic and/or intestinal) can have significant clinical consequences.

Effect of co-medications on paritaprevir, ritonavir, ombitasvir, dasabuvir and ribavirin pharmacokinetics: analysis of data from seven Phase II/III trials

BACKGROUND

The three drug direct-acting antiviral regimen (3D regimen) of ombitasvir, paritaprevir/ritonavir and dasabuvir, with and without ribavirin, was evaluated in one Phase II trial and six Phase III trials in over 2,300 HCV genotype-1-infected patients. Patients continued taking their protocol-permitted co-medications while receiving the 3D ± ribavirin regimen. The effects of the co-medications on exposures of the 3D regimen and ribavirin were examined.

METHODS

Population pharmacokinetic model-predicted steady-state area under the curve (AUC_24,ss) values were evaluated in the presence/absence of the co-medications. Interactions resulting in a greater than 50% reduction or 100% increase in an AUC_24,ss value were examined as covariates for an effect on apparent clearance (CL/F).

RESULTS

More than 1,200 co-medications belonging to 15 drug classes and/or 19 enzyme and transporter inhibitor and/or inducer categories were used concomitantly with the 3D regimen in the trials. Approximately 1,500 patients (65%) in Phase III trials received two or more co-medications from multiple drug classes or categories. No co-medication class/category decreased or increased ombitasvir, dasabuvir, ritonavir or ribavirin AUC_24,ss by more than half or twofold, respectively. Opioids, antipsychotics, anti-epileptics, antidiabetics and non-ethinyl estradiol-containing hormone replacement therapies appeared to have an effect (AUC_24,ss ratio ≤0.5 or ≥2.0) on paritaprevir exposures. However, when these classes were included in the paritaprevir population pharmacokinetic model, only opioids and antidiabetics had a statistically significant effect on CL/F, but with no clinically meaningful increase in exposures (≤55%).

CONCLUSIONS

No dose adjustment is necessary for the 3D ± ribavirin regimen when used with the co-medications included in this analysis as there were no clinically meaningful effects on exposures of the DAAs.

Investigation of the effect of food and omeprazole on the relative bioavailability of a single oral dose of 240 mg faldaprevir, a selective inhibitor of HCV NS3/4 protease, in an open-label, randomized, three-way cross-over trial in healthy participants

Objectives

This study was conducted to investigate the effect of food and coadministration of omeprazole on the relative bioavailability (BA) of faldaprevir (FDV).

Methods

Fifteen healthy participants participated in this open-label, randomized, three-way cross-over study. Faldaprevir was administered as a 240 mg single dose during fasting state, following intake of a high-fat breakfast, or following omeprazole 40 mg q.d. dosing for 5 days. PK samples were collected on the day of faldaprevir administration.

Key findings

We found geometric mean (gMean) AUC0–∞ values for faldaprevir of 48 200, 37 900 and 36 000 ng h/ml under the fed, fasted and omeprazole coadministration conditions respectively. Similarly, gMean Cmax values for faldaprevir were 2600, 2030, 1920 ng/ml under the same respective conditions. The adjusted gMean ratio between the fed and fasted condition was approximately 120% for both AUC0–∞ and Cmax, while the ratio of omeprazole coadministration to fasted condition was approximately 94%. Faldaprevir was safe and well tolerated in the study.

Conclusions

Administration of a single dose of 240 mg faldaprevir after high-fat breakfast led to a modest, clinically irrelevant increase in faldaprevir exposure, while coadministration of omeprazole did not influence faldaprevir exposure.

Dosing Recommendations for Concomitant Medications During 3D Anti-HCV Therapy

The development of direct-acting antiviral (DAA) agents has reinvigorated the treatment of hepatitis C virus infection. The availability of multiple DAA agents and drug combinations has enabled the transition to interferon-free therapy that is applicable to a broad range of patients. However, these DAA combinations are not without drug-drug interactions (DDIs). As every possible DDI permutation cannot be evaluated in a clinical study, guidance is needed for healthcare providers to avoid or minimize drug interaction risk. In this review, we evaluated the DDI potential of the novel three-DAA combination of ombitasvir, paritaprevir, ritonavir, and dasabuvir (the 3D regimen) with more than 200 drugs representing 19 therapeutic drug classes. Outcomes of these DDI studies were compared with the metabolism and elimination routes of prospective concomitant medications to develop mechanism-based and drug-specific guidance on interaction potential. This analysis revealed that the 3D regimen is compatible with many of the drugs that are commonly prescribed to patients with hepatitis C virus infection. Where interaction is possible, risk can be mitigated by paying careful attention to concomitant medications, adjusting drug dosage as needed, and monitoring patient response and/or clinical parameters.

Drug-Drug Interaction of Omeprazole With the HCV Direct-Acting Antiviral Agents Paritaprevir/Ritonavir and Ombitasvir With and Without Dasabuvir

Paritaprevir (administered with low-dose ritonavir), ombitasvir, and dasabuvir are direct-acting antiviral agents administered as combination regimens for the treatment of chronic hepatitis C virus infection. Drug-drug interactions between 2D (ombitasvir/paritaprevir/ritonavir) or 3D (ombitasvir/paritaprevir/ritonavir and dasabuvir) regimens and omeprazole, a CYP2C19 substrate and acid-reducing agent, were evaluated in 24 healthy volunteers. Subjects received omeprazole (40 mg once daily) on day 1 and days 20-24 and the 2D or 3D regimen (ombitasvir/paritaprevir/ritonavir 25/150/100 mg once daily ± dasabuvir 250 mg twice daily) on days 6-24. Compared with omeprazole alone, coadministration with the 2D or 3D regimen decreased omeprazole geometric mean Cmax and AUCt values by 40% to 50%. Ombitasvir, dasabuvir, and ritonavir mean exposures showed <10% change, and paritaprevir mean exposures showed <20% change when the 2D or 3D regimen was administered with omeprazole compared with administration without omeprazole. Although no a priori dose adjustment is needed, a higher omeprazole dose should be considered if clinically indicated when coadministered with the 2D or 3D regimen. No dose adjustment is required for the 2D or 3D regimen when administered with omeprazole, other acid-reducing agents, or CYP2C19 inhibitors.

Drug Interactions with the Direct-Acting Antiviral Combination of Ombitasvir and Paritaprevir-Ritonavir

The two direct-acting antiviral (2D) regimen of ombitasvir and paritaprevir (administered with low-dose ritonavir) is being developed for treatment of genotype subtype 1b and genotypes 2 and 4 chronic hepatitis C virus (HCV) infection. Drug-drug interactions were evaluated in healthy volunteers to develop dosing recommendations for HCV-infected subjects. Mechanism-based interactions were evaluated for ketoconazole, pravastatin, rosuvastatin, digoxin, warfarin, and omeprazole. Interactions were also evaluated for duloxetine, escitalopram, methadone, and buprenorphine-naloxone. Ratios of geometric means with 90% confidence intervals for the maximum plasma concentration and the area under the plasma concentration-time curve were estimated to assess the magnitude of the interactions. For most medications, coadministration with the 2D regimen resulted in a <50% change in exposures. Ketoconazole, digoxin, pravastatin, and rosuvastatin exposures increased by up to 105%, 58%, 76%, and 161%, respectively, and omeprazole exposures decreased by approximately 50%. Clinically meaningful changes in ombitasvir, paritaprevir, or ritonavir exposures were not observed. In summary, all 11 medications evaluated can be coadministered with the 2D regimen, with most medications requiring no dose adjustment. Ketoconazole, digoxin, pravastatin, and rosuvastatin require lower doses, and omeprazole may require a higher dose. No dose adjustment is required for the 2D regimen.

Drug-drug interactions of telaprevir and boceprevir in HCV-monoinfected and HIV/HCV-coinfected patients can modify the adherence

BACKGROUND & AIMS

The first generation protease inhibitors, boceprevir (BOC) and telaprevir (TVR), are both CYP3A4 inhibitors, which predispose drug-drug interactions (DDIs). The aim of this study was to evaluate the prevalence of potential DDIs, the management of outpatient medication and its impact on adherence and efficacy to antiviral treatment in hepatitis C virus (HCV)-monoinfected and human immunodeficiency virus (HIV)/HCV-coinfected patients receiving BOC and TVR.

METHODS

The usual medication starting with BOC or TVR was screened by the pharmacist of the multidisciplinary support programme (MSP) for potential DDIs. Recommendations were made to avoid significant DDIs, and changes in the baseline medication were recorded. Adherence to antiviral treatment was considered as 80/80/95% of total doses. Sustained virological response was assessed at week 12 (SVR12).

RESULTS

At least one potential DDI was found in 70 (64.8%) patients, 45 (54.2%) being HCV-monoinfected and 25 (100%) HIV/HCV-coinfected (P < 0.01). Baseline treatment modifications were required in 38 (35.2%) patients. Adherence and SVR12 were higher in patients without DDIs (86.8%) and (67.6%) compared to those with DDIs (62.8%) (P = 0.021) and (47.2%) (P = 0.097) respectively.

CONCLUSIONS

More than half of the patients were at risk of presenting DDIs, leading to changes in the baseline medication in one-third of the patients. Drug interactions are frequent in patients with lower adherence.