Recommendations for the safe use of direct oral anticoagulants in patients with cirrhosis based on a systematic review of pharmacokinetic, pharmacodynamic and safety data.

PURPOSE: The popularity of direct oral anticoagulants (DOACs) is increasing among patients with cirrhosis. Cirrhosis has a major impact on the pharmacokinetics of drugs, potentially increasing adverse events. Safe use of drugs in cirrhosis requires a diligent risk-benefit analysis. The aim of this study is to develop practice recommendations for safe use of DOACs in cirrhosis based on a systematic review of pharmacokinetic, pharmacodynamic and safety data. METHODS: We conducted a systematic literature search to identify studies on pharmacokinetics, pharmacodynamics and safety of DOACs in cirrhosis. Data were collected and presented in summary tables by severity of cirrhosis using the Child-Turcotte-Pugh (CTP) classification. A multidisciplinary expert panel evaluated the results and classified the DOACs according to safety. RESULTS: Fifty four studies were included. All DOACs were classified as 'no additional risks known' for CTP A. For CTP B, apixaban, dabigatran and edoxaban were classified as 'no additional risks known'. Apixaban and edoxaban showed fewer adverse events in patients with cirrhosis, while dabigatran may be less impacted by severity of cirrhosis based on its pharmacokinetic profile. Rivaroxaban was classified as 'unsafe' in CTP B and C based on significant pharmacokinetic alterations. Due to lack of data, apixaban, dabigatran and edoxaban were classified as 'unknown' for CTP C. CONCLUSION: DOACs can be used in patients with CTP A cirrhosis, and apixaban, dabigatran and edoxaban can also be used in CTP B. It is recommended to avoid rivaroxaban in CTP B and C. There is insufficient evidence to support safe use of other DOACs in CTP C cirrhosis.

Modifying Tacrolimus-related Toxicity After Liver Transplantation Comparing Life Cycle Pharma Tacrolimus Versus Extended-released Tacrolimus: A Multicenter, Randomized Controlled Trial.

Background: The aim of this open-label, multicenter, randomized controlled study was to investigate whether the life cycle pharma (LCP)-tacrolimus compared with the extended-release (ER)-tacrolimus formulation results in a difference in the prevalence of posttransplant diabetes, hypertension and chronic kidney disease (CKD) at 12 mo after liver transplantation. Methods: Patients were 1:1 randomized to either of the 2 tacrolimus formulations. The primary endpoint was defined as a composite endpoint of any of 3 events: sustained (>3 mo postrandomization) posttransplant diabetes, new-onset hypertension, and/or CKD, defined as estimated glomerular filtration rate <60 mL/min/1.73 m2 for >3 m during the follow-up. Results: In total, 105 patients were included. In the intention-to-treat analysis, a statistically significant lower proportion of liver transplant recipients in the LCP-tacrolimus group reached the composite primary endpoint at 12 mo compared with the ER-tacrolimus group (50.9% [27/53], 95% confidence interval [CI], 37.9%-63.9% versus 71.2% [37/52], 95% CI, 57.7%-81.7%; risk difference: 0.202; 95% CI, 0.002-0.382; P = 0.046). No significant difference was found in the per protocol analysis. In the intention-to-treat and per protocol population, fewer liver transplant recipients in the LCP-tacrolimus group developed CKD and new-onset hypertension compared with the ER-tacrolimus group. No differences in rejection rate, graft and patient survival were found. Conclusions: A statistically significant and clinically relevant reduction in the prevalence of the composite primary endpoint was found in the LCP-tacrolimus group compared with the ER-tacrolimus group in the first year after liver transplantation with comparable efficacy.

Health-related Quality of Life and Fatigue in Liver Transplant Recipients Receiving Tacrolimus Versus Sirolimus-based Immunosuppression: Results From a Randomized Trial.

BACKGROUND: The impact of different immunosuppression regimes on the health-related quality of life (HRQoL) and the severity of fatigue in liver transplant recipients is largely unknown. We investigated the impact of a sirolimus-based regimen compared with a tacrolimus (TAC)-based regimen on the HRQoL and the severity of fatigue. METHODS: In this multicenter, open-label, randomized, controlled trial, 196 patients were randomized 90 d after transplantation to (1) once daily normal-dose TAC or (2) once daily combination therapy of low-dose sirolimus and TAC. HRQoL was measured with the EQ-5D-5L questionnaire, the EQ-visual analog scale, and the severity of fatigue questionnaire Fatigue Severity Score (FSS). The EQ-5D-5L scores were translated to societal values. We examined the HRQoL and the FSS over the course of the study by fitting generalized mixed-effect models. RESULTS: Baseline questionnaires were available for 87.7% (172/196) of the patients. Overall, patients reported the least problems in the states of self-care and anxiety/depression and the most problems in the states of usual activities and pain/discomfort. No significant differences in HrQol and FSS were seen between the 2 groups. During follow-up, the societal values of the EQ-5D-5L health states and the patient's self-rated EQ-visual analog scale score were a little lower than those of the general Dutch population in both study arms. CONCLUSIONS: The HRQoL and FSS were comparable in the 36 mo after liver transplantation in both study groups. The HRQoL of all transplanted patients approximated that of the general Dutch population, suggesting little to no residual symptoms in the long term after transplantation.

Oral antibiotics lower mycophenolate mofetil drug exposure, possibly by interfering with the enterohepatic recirculation: A case series.

Mycophenolate mofetil has an important role as immunosuppressive agent in solid organ transplant recipients. Exposure to the active mycophenolic acid (MPA) can be monitored using therapeutic drug monitoring. We present three cases in which MPA exposure severely decreased after oral antibiotic coadministration. By diminishing gut bacteria ß-glucuronidase activity, oral antibiotics can prevent deglucuronidation of the inactive MPA-7-O-glucuronide metabolite to MPA and thereby possibly prevent its enterohepatic recirculation. This pharmacokinetic interaction could result in rejection, which makes it clinically relevant in solid organ transplant recipients, especially when therapeutic drug monitoring frequency is low. Routine screening for this interaction, preferably supported by clinical decision support systems, and pragmatic close monitoring of the MPA exposure in cases is advised.

Three-year results of renal function in liver transplant recipients on low-dose sirolimus and tacrolimus: a multicenter, randomized, controlled trial.

The aim of this study was to investigate whether the combination of low-dose sirolimus (SRL) and low-dose extended-release tacrolimus (TAC) compared to normal-dose extended-release TAC results in a difference in the renal function and comparable rates of rejection, graft and patient survival at 36 months after transplantation. This study was an open-label, multicenter randomized, controlled trial. Patients were randomized to once-daily normal-dose extended-release TAC (control group) or once-daily combination therapy of SRL and low-dose extended-release TAC (interventional group). The primary endpoint was the cumulative incidence of chronic kidney disease (CKD) defined as grade ≥3 (estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2) at 36 months after transplantation. In total, 196 patients were included. CKD at 36 months was not different between the control and interventional group (50.8%, 95% CI: 39.7%-59.9%) vs. 43.7%, 95% CI: 32.8%-52.8%). Only at 6 months after transplantation, the eGFR was higher in the interventional group compared to the control group (mean eGFR 73.1±15 vs. 67.6±16 mL/min/1.73 m2, p=0.02) in the intention-to-treat population. No differences in the secondary endpoints and the number of serious adverse events were found between the groups. Once daily low-dose SRL combined with low-dose extended-release TAC does ultimately not provide less CKD grade ≥3 at 36 months compared to normal-dose extended-release TAC.

Evaluation of medication-related problems in liver transplant recipients with and without an outpatient medication consultation by a clinical pharmacist: a cohort study.

BACKGROUND: Transplant recipients undergo significant changes in their medication regimen during follow-up and are at an increased risk for medication-related problems (MRPs). AIM: This study aimed to compare the prevalence and types of MRPs and interventions in liver transplant recipients with and without an outpatient medication consultation by a clinical pharmacist as well as the satisfaction with information about medicines and medication adherence. METHOD: We performed a single-center, observational cohort study. A retro- and prospective cohort were used and subdivided in a group that did and did not receive a medication consultation. The prevalence and types of MRPs and interventions were identified and categorized. The satisfaction parameters were evaluated using validated questionnaires. RESULTS: Included were 291 patients. In total, 368 MRPs were identified in 197 patients in the non-medication consultation cohort (median 1; range 1-3 per patient) and 248 MRPs in 94 patients in the medication consultation cohort (median 2; range 1-4 per patient). In the medication consultation cohort, significantly fewer MRPs as unnecessary drugs (17.3% versus 58.7%, p < 0.001), suboptimal therapy (2.4% versus 9.5%, p < 0.001), untreated indication (2.8% versus 6.8%, p = 0.040) and underdosed drugs (0.4% versus 6.3%, p < 0.001) were identified. In the non-medication consultation cohort significantly more patients used unnecessary drugs (72.1% versus 39.4%, p < 0.001) compared to the medication consultation cohort. Patients in both cohorts are satisfied with the information about medicines and reported a high medication adherence. CONCLUSION: Patients in the medication consultation cohort had significantly fewer MRPs and used significantly less unnecessary drugs. Including a clinical pharmacist to the post-transplant care has an added value.

Therapeutic drug monitoring of immunosuppressive drugs in hepatology and gastroenterology.

Immunosuppressive drugs have been key to the success of liver transplantation and are essential components of the treatment of inflammatory bowel disease (IBD) and autoimmune hepatitis (AIH). For many but not all immunosuppressants, therapeutic drug monitoring (TDM) is recommended to guide therapy. In this article, the rationale and evidence for TDM of tacrolimus, mycophenolic acid, the mammalian target of rapamycin inhibitors, and azathioprine in liver transplantation, IBD, and AIH is reviewed. New developments, including algorithm-based/computer-assisted immunosuppressant dosing, measurement of immunosuppressants in alternative matrices for whole blood, and pharmacodynamic monitoring of these agents is discussed. It is expected that these novel techniques will be incorporate into the standard TDM in the next few years.

Medication-Related Problems in Liver Transplant Recipients in the Outpatient Setting: A Dutch Cohort Study.

Background: After liver transplantation (LTx), adherence to immunosuppressive medication and avoidance of contra-indicated drugs is essential for long-term survival. This study aimed to investigate the prevalence, types and severity of medication-related problems (MRPs) and interventions initiated by a clinical pharmacist (CP) in a cohort of LTx recipients in the outpatient setting. Method: This study was a retrospective, observational study in LTx recipients that visited the outpatient clinic for an annual check-up. A 20-minutes consultation with a CP consisted of medication reconciliation and consultation about medication, adherence, and adverse drug reactions (ADRs). Discrepancies between actual and intended drug use, and MRPs were identified and the severity of MRPs was assessed. Potential interventions were discussed with the patient and the treating physician and evaluated after one year. Results: The CP counseled 64 LTx recipients and found 96 discrepancies in 37 patients. Most discrepancies (60.4%, n = 58) concerned missing medications. In total, 98 MRPs were identified in 53 patients (median 2; range 1-5 per patient), with a total of 113 interventions. Most frequent MRPs were: ADRs (22.4%, n = 22), nonadherence (19.3%, n = 19), unnecessary drugs (16.3%, n = 16) and undertreatment (12.2%, n = 12). Interventions most frequently proposed included optimization of dosage regimen (21.2%, n = 24), individualized recommendation regarding compliance (16.8%, n = 19) and drug discontinuation (12.4%, n = 14). After one year, 15 of the 19 patients (79%) experienced no longer compliance issues and 27 of the 29 patients (93%) used no drugs with indication issues anymore. Conclusion: The CP in an outpatient monitoring program for LTx recipients can signal relevant discrepancies and MRPs. This leads to interventions that are accepted by both the patients and the physicians, with a positive effect after one year.

Determining the therapeutic range for ribavirin in transplant recipients with chronic hepatitis E virus infection.

The aim of this study was to define the therapeutic range for ribavirin (RBV) in transplant recipients with chronic hepatitis E virus (HEV) infection. In this retrospective multicentre cohort study, data of adult transplant recipients with chronic HEV infection, who had been treated with RBV monotherapy between 01-3-2008 and 01-08-2018, were included. ROC curve analyses were performed, and the half-maximal effective RBV concentration was calculated to determine a representative therapeutic range. In 96 patients, RBV monotherapy for a median of three months resulted in a sustained virologic response in 63.5% of the patients, while 88.5% of the patients developed anaemia. RBV plasma concentrations at steady state were significantly higher in clinical responders compared with clinical non-responders: median 1.96 (IQR 1.81-2.70) versus 0.49 (IQR 0.45-0.73) mg/L, P = .0004. RBV caused a dose-dependent haemoglobin reduction with higher RBV plasma concentrations resulting in more haemoglobin reduction. The therapeutic range for RBV for chronic HEV infection in transplant recipients ranges between 1.8 and 2.3 mg/L.

Differences in CYP3A genotypes of a liver transplant recipient and the donor liver graft and adjustment of tacrolimus dose.

Tacrolimus (Tac) is well established as main immunosuppressant in most immunosuppressive regimens in solid organ transplantation. Due to the narrow therapeutic window, pre dose Tac levels (C0) are monitored in all patients receiving Tac to reach optimal therapeutic levels. Tac is metabolized in the liver and intestine by the cytochrome P450 3A (CYP3A) isoforms CYP3A4 and CYP3A5. We present a case of an African American woman who underwent a liver transplantation in which adequate Tac levels were difficult to accomplish due to differences in cytochrome P450 3A4/5 (CYP3A4/5) polymorphisms of the transplant recipient and the donor liver graft. This case report highlights that genotyping the liver transplant recipient and the donor liver graft might provide data which could be used to predict the tacrolimus metabolism post transplantation.

Comparison of hypersensitivity reactions of intravenous iron: iron isomaltoside-1000 (Monofer® ) versus ferric carboxy-maltose (Ferinject® ). A single center, cohort study.

AIMS: Intravenous iron supplementation is widely used to treat iron deficiency and iron deficiency anemia when oral iron administration is ineffective or poorly tolerated. Hypersensitivity reactions (HSRs) during infusions are rare, but can be life-threatening. This study aimed to compare the risk for HSRs with the intravenous administration of iron isomaltoside-1000 and ferric carboxymaltose for the treatment of iron deficiency and iron deficiency anemia. METHODS: This was a single-centre cohort study. Nurses and physicians were instructed to fill out an HSR registration form with every administration of intravenous iron. HSRs were distinguished into serious and non-serious HSRs using the Ring and Messmer classification. RESULTS: HSRs occurred in 18/836 (2.1%) ferric carboxymaltose and 43/496 (8.7%) iron isomaltoside-1000 administrations. The crude risk for HSRs was 75% lower after ferric carboxymaltose treatment (RR = 0.248, 95% CI: 0.145-0.426, P < 0.0001). The risk for grade II HSRs was 88% lower after ferric carboxymaltoside (RR = 0.123, 95% CI: 0.051-0.294). The likelihood of HSRs was 3.4 times higher after the administration of iron isomaltoside-1000 (95% CI: 1.910-6.093, P < 0.0001). Regardless of the type of intravenous iron, patients with comorbidities have a factor 3.6 higher risk (95% CI: 1.899-6.739, P < 0.0001). CONCLUSIONS: Ferric carboxymaltose is associated with a 75% lower risk for HSRs compared with iron isomaltoside-1000 in our population. The presence of a comorbidity raises the likelihood of an HSR by a factor of three regardless of the type of intravenous iron infusion. Further research is needed to clarify the underlying mechanism in various patient groups.

Therapeutic Drug Monitoring of Methotrexate in Plasma Using Ultra High-Performance Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry: Necessary After Administration of Glucarpidase in Methotrexate Intoxications.

High-dose methotrexate (HD-MTX) is used to treat a variety of cancers. In all patients receiving HD-MTX, plasma MTX levels are monitored mainly to anticipate rescue therapy to prevent adverse events. We present 2 children treated with HD-MTX and afterward treated with glucarpidase at different time-points after their HD-MTX infusions. After the administration of glucarpidase, a nontoxic metabolite of MTX cross-reacts with MTX in the standard immunoassay (Abbott Diagnostics, Hoofddorp, the Netherlands) resulting in an artificially elevated MTX level. An artificially elevated MTX level results in unnecessarily long folinic acid administration, which decreases the effectivity of MTX. This grand round highlights the importance of measuring plasma MTX levels after the administration of glucarpidase with an ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method instead of with an immunoassay.

In vitro pharmacokinetics/pharmacodynamics of the combination of avibactam and aztreonam against MDR organisms.

OBJECTIVES: The combination of aztreonam and avibactam has been proposed for the treatment of infections caused by metallo-ß-lactamase-producing Gram-negative organisms, given the stability of aztreonam against metallo-ß-lactamases plus the broad coverage of avibactam against AmpC ß-lactamases and ESBLs. This study aimed to evaluate the efficacy of the combination against four clinical isolates with defined but diverse ß-lactamase profiles. METHODS: The MICs of aztreonam were determined without and with avibactam (1, 2, 4, 8 and 16 mg/L). Using the MIC values, the static time-kill kinetic studies were designed to encompass aztreonam concentrations of 0.25, 0.5, 1, 2 and 4 times the MIC at the respective avibactam concentrations from 0 to 8 mg/L. Aztreonam and avibactam concentrations were determined by LC-MS/MS during the course of the time-kill kinetic studies to evaluate whether avibactam protects aztreonam from degradation. RESULTS: Three of the four isolates had aztreonam MICs ≥128 mg/L in monotherapy. Dramatically increasing susceptibility associated with a decrease in aztreonam MIC was observed with increasing avibactam concentration. Against all isolates, the combinations resulted in greater killing with a much lower dose requirement for aztreonam. The resulting changes in base-10 logarithm of cfu/mL at both the 10 h and 24 h references (versus 0 h) were synergistic. In contrast, a significantly higher concentration of aztreonam in the monotherapy was required to produce the same kill as that in the combination therapy, due to rapid aztreonam degradation in two isolates. CONCLUSIONS: The aztreonam/avibactam combination protects aztreonam from hydrolysis and provides synergy in antimicrobial activity against multiple ß-lactamase-expressing strains with a wide MIC range.

Evaluation of in vitro synergy between vertilmicin and ceftazidime against Pseudomonas aeruginosa using a semi-mechanistic pharmacokinetic/pharmacodynamic model.

The aim of this study was to develop a semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model to evaluate the in vitro synergy between vertilmicin and ceftazidime against Pseudomonas aeruginosa. The in vitro antimicrobial activity of vertilmicin alone was initially assessed by static and dynamic time-kill experiments against three bacterial strains, including MSSA, MRSA and P. aeruginosa. The combined killing effect with ceftazidime was then evaluated in a static time-kill study against P. aeruginosa. Vertilmicin displayed a concentration-dependent killing effect against the three bacterial strains, and its short half-life may possibly have a dramatic impact on antimicrobial activities. A two-compartment pharmacodynamic model consisting of drug-susceptible and -resistant compartments was developed to characterise the relationship between drug exposure and bacterial response for the time-kill curves from both monotherapy and combination therapy. Loewe additivity was incorporated into the pharmacodynamic model to describe the drug-drug interactive effect in the combination therapy. For monotherapy, the estimated EC50 of the dynamic time-kill study against each strain was close to its MIC but was higher than that of the static time-kill study. The EC50 of combination therapy was estimated at 2.67 mg/L compared with 4.54 mg/L in monotherapy, indicating an enhanced bactericidal capacity. The drug-drug interactive effect was not significantly synergistic but highly varied at each specific combination. Potential synergistic combinations could be screened using PK/PD modelling and simulation. These results demonstrated that PK/PD modelling provides an innovative approach to assist dose selection of combination vertilmicin and ceftazidime for future clinical study design.