No relevant pharmacokinetic interaction between pantoprazole and mycophenolate in renal transplant patients: a randomized crossover study

Co prescription of anti-acid therapy reduces the bioavailability of mycophenolate mofetil in systemic sclerosis patients: A crossover trial

OBJECTIVE

Mycophenolate mofetil (MMF) is an effective treatment option for interstitial lung disease (ILD) in systemic sclerosis (SSc). Many patients require co-administration of proton pump inhibitors (PPI) or H2 receptor blockers (HRB) because of various gastrointestinal (GI) manifestations in SSc. Co-treatment with PPI or HRB have shown to reduce serum drug levels in post-transplant patients. We wanted to see if there is a similar phenomenon for Mycophenolate in SSc.

METHODS

Twenty SSc patients, who were on a stable dose of MMF (1.5-3 g) underwent a sequential cross over study with MMF alone in the first month, followed by co-treatment with Ranitidine and then Esomeprazole in the second and third month respectively. Estimation of 12-hour area under curve (AUC) of Mycophenolic Acid (MPA) levels and total GI score were calculated at the end of each month and compared between the treatment arms. [Trial registration: CTRI/2020/06/025,939] RESULTS: Co-administration of esomeprazole was associated with 32.7% (mean difference = 22.28 μg h ml-1) reduction in mean AUC MPA, whereas ranitidine caused a reduction of 21.97% (mean difference = 14.93 μg h ml-1) in MPA AUC when compared to MMF without anti-acid therapies. The addition of ranitidine or esomeprazole resulted in significant reduction in the total GI score.

CONCLUSION

Co-administration of PPI or HRB can significantly reduce the bioavailability of MMF in patients with SSc. To avoid therapeutic failure of MMF drug level monitoring is essential when these agents are co-prescribed with MMF.

Population Pharmacokinetics of Mycophenolic Acid in Renal Transplant Patients: A Comparison of the Early and Stable Posttransplant Stages

Mycophenolic acid (MPA) is an antimetabolic immunosuppressive drug widely used in solid organ transplantation and autoimmune diseases. Pharmacokinetics (PK) of MPA demonstrates high inter- and intra-variability. The aim of this study was to compare the population PK properties of MPA in adult renal transplant patients in the early and stable post-transplant stages and to simulate an optimal dosing regimen for patients at different stages. A total of 51 patients in the early post-transplant period (1 week after surgery) and 48 patients in the stable state (5.5–10 years after surgery) were included in the study. In the two-compartment population PK model, CL/F (23.36 L/h vs. 10.25 L/h) and V/F (78.07 vs. 16.24 L) were significantly different between the two stages. The dose-adjusted area under the concentration time curve (AUC_ss,12h/dose) for patients in the early stage were significantly lower than those for patients in the stable state (40.83 ± 22.26 mg h/L vs. 77.86 ± 21.34 mg h/L; p < 0.001). According to Monte Carlo simulations, patients with 1.0–1.5 g of mycophenolate mofetil twice daily in the early phase and 0.50–0.75 g twice daily in the stable phase had a high probability of achieving an AUC_ss,12h of 30–60 mg h/L. In addition, limited sampling strategies showed that two 4-point models (C0-C1-C2-C4 and C1-C2-C3-C6) performed well in predicting MPA exposure by both Bayesian estimate and regression equation and could be applied in clinical practice to assist therapeutic drug monitoring of MPA.

Personalized Therapy for Mycophenolate: Consensus Report by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology

ABSTRACT

When mycophenolic acid (MPA) was originally marketed for immunosuppressive therapy, fixed doses were recommended by the manufacturer. Awareness of the potential for a more personalized dosing has led to development of methods to estimate MPA area under the curve based on the measurement of drug concentrations in only a few samples. This approach is feasible in the clinical routine and has proven successful in terms of correlation with outcome. However, the search for superior correlates has continued, and numerous studies in search of biomarkers that could better predict the perfect dosage for the individual patient have been published. As it was considered timely for an updated and comprehensive presentation of consensus on the status for personalized treatment with MPA, this report was prepared following an initiative from members of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT). Topics included are the criteria for analytics, methods to estimate exposure including pharmacometrics, the potential influence of pharmacogenetics, development of biomarkers, and the practical aspects of implementation of target concentration intervention. For selected topics with sufficient evidence, such as the application of limited sampling strategies for MPA area under the curve, graded recommendations on target ranges are presented. To provide a comprehensive review, this report also includes updates on the status of potential biomarkers including those which may be promising but with a low level of evidence. In view of the fact that there are very few new immunosuppressive drugs under development for the transplant field, it is likely that MPA will continue to be prescribed on a large scale in the upcoming years. Discontinuation of therapy due to adverse effects is relatively common, increasing the risk for late rejections, which may contribute to graft loss. Therefore, the continued search for innovative methods to better personalize MPA dosage is warranted.

Effect of the proton-pump Inhibitor pantoprazole on MycoPhenolic ACid exposure in kidney and liver transplant recipienTs (IMPACT study): a randomized trial

BACKGROUND

Mycophenolic acid (MPA) is widely utilized as an immunosuppressant in kidney and liver transplantation, with reports suggesting an independent relationship between MPA concentrations and adverse allograft outcome. Proton-pump inhibitors (PPIs) may have variable effects on the absorption of different MPA formulations leading to differences in MPA exposure.

METHODS

A multicentre, randomized, prospective, double-blind placebo-controlled cross-over study was conducted to determine the effect of the PPI pantoprazole on the MPA and its metabolite MPA-glucuronide (MPA-G) area under the curve (AUC) >12 h (MPA-AUC12 h) in recipients maintained on mycophenolate mofetil (MMF) or enteric-coated mycophenolate sodium (EC-MPS). We planned a priori to examine separately recipients maintained on MMF and EC-MPS for each pharmacokinetic parameter. The trial (and protocol) was registered with the Australian New Zealand Clinical Trials Registry on 24 March 2011, with the registration number of ACTRN12611000316909 ('IMPACT' study).

RESULTS

Of the 45 recipients screened, 40 (19 MMF and 21 EC-MPS) were randomized. The mean (standard deviation) recipient age was 58 (11) years with a median (interquartile range) time post-transplant of 43 (20-132) months. For recipients on MMF, there was a significant reduction in the MPA-AUC12 h [geometric mean (95% confidence interval) placebo: 53.9 (44.0-65.9) mg*h/L versus pantoprazole: 43.8 (35.6-53.4) mg*h/L; P = 0.004] when pantoprazole was co-administered compared with placebo. In contrast, co-administration with pantoprazole significantly increased MPA-AUC12 h [placebo: 36.1 (26.5-49.2) mg*h/L versus pantoprazole: 45.9 (35.5-59.3) mg*h/L; P = 0.023] in those receiving EC-MPS. Pantoprazole had no effect on the pharmacokinetic profiles of MPA-G for either group.

CONCLUSIONS

The co-administration of pantoprazole substantially reduced the bioavailability of MPA in patients maintained on MMF and had the opposite effect in patients maintained on EC-MPS, and therefore, clinicians should be cognizant of this drug interaction when prescribing the different MPA formulations.

Therapeutic drug monitoring of mycophenolate mofetil in pediatric patients: novel techniques and current opinion

Introduction: Mycophenolate mofetil (MMF) is an ester prodrug of the immunosuppressant mycophenolic acid (MPA) and is recommended and widely used for maintenance immunosuppressive therapy in solid organ and stem-cell transplantation as well as in immunological kidney diseases. MPA is a potent, reversible, noncompetitive inhibitor of the inosine monophosphate dehydrogenase (IMPDH), a crucial enzyme in the de novo purine synthesis in T- and B-lymphocytes, thereby inhibiting cell-mediated immunity and antibody formation. The use of therapeutic drug monitoring (TDM) of MMF is still controversial as outcome data of clinical trials are equivocal. Areas covered: This review covers in great depth the existing literature on TDM of MMF in the field of pediatric (kidney) transplantation. In addition, the relevance of TDM in immunological kidney diseases, in particular childhood nephrotic syndrome is highlighted. Expert opinion: TDM of MMF has the potential to optimize therapy in pediatric transplantation as well as in nephrotic syndrome. Limited sampling strategies to estimate MPA exposure increase its feasibility. Future perspectives rather encompass approaches reflecting total immunosuppressive load than single drug TDM.

Different Routes of Proton Pumps Inhibitors Co-Administration have Significant Impact on Mycophenolate Acid (MPA) Serum Levels in Heart Transplant Recipients

Background

Antiproliferative drugs including mycophenolate mofetil (MMF) are widely accepted part of an immunosuppressive therapy following heart transplantation. Proton pump inhibitors (PPIs) are routinely administered after cardiac surgery procedures including transplantation. They may also have impact on mycophenolate acid (MPA) serum levels.

Material/Methods

There were 30 consecutive patients (28 male and 2 female patients) with a mean age of 45±12 years who were enrolled into this study. MPA serum levels were studied; PPIs were intravenously and orally administered.

Results

The mean MPA plasma concentrations were statistically significantly different between parenteral group (2.3±1.4 umg/mL) and oral group (3.1±2.2 umg/mL) (P=0.036) before immunosuppressive drug administration (C-0 time). There was a statistically significant different drug concentration at the second sample time C-30 (30 minutes after drug intake) reaching 4.4±2.8 umg/mL versus 7.9±4.5 umg/mL (P<0.05). There was no statistically significant difference in MPA plasma concentration at the 3^rd measurement C-120 (10.7±4,9 umg/mL versus 9.8±5 umg/mL) (P=0.3). There is a statistically significant different MMF serum concentration after oral intake and intravenous infusion at C-30 (2.4±1.4 in group 1 versus 3.3±2.5 in group 2, P<0.036) but not at C-120 time interval (8.9±5.0 versus 9.8±5.3 in group 1 and 2, respectively) (P=0.3).

Conclusions

Our study was the first study that compared different routes of PPI co-administration on MPA serum levels in a transplant recipient group. Our study revealed that the parenteral route of administration only slowed not decreased MPA pharmacokinetics within 120 minutes following MMF administration.

The Effect of Proton Pump Inhibitor Use on Renal Function in Kidney Transplanted Patients

Recently, proton pump inhibitor (PPI) intake has been linked to acute kidney injury and chronic kidney disease. The objective of this study was to assess the effect of PPIs on renal function and rejection rate in kidney transplant patients. We performed a single center, retrospective analysis of 455 patients who received a kidney transplant between May 2010 and July 2015. Median follow-up time was 3.3 years. PPI prescription was assessed in half-year intervals. Primary outcome parameters were the estimated glomerular filtration rate (eGFR), change in the eGFR, and >30% and >50% eGFR decline for different time periods (up to four years post-transplantation). Our secondary outcome parameter was occurrence of biopsy proven acute rejection (BPAR) in the first two years after transplantation. Except for >30% eGFR decline from half a year to two years post-transplantation (p = 0.044) and change in the eGFR, >30% and >50% eGFR decline showed no association with PPI intake in our patient cohort (p > 0.05). Similarly, by analyzing 158 rejection episodes, BPAR showed no correspondence with mean daily PPI intake. We conclude that prolonged PPI intake has no relevant adverse effect on kidney transplant function or rejection rates. Polypharmacy, however, remains a problem in renal transplant recipients and it is thus advisable to question the necessity of PPI prescriptions when clear indications are missing.

Inosine Monophosphate Dehydrogenase Pharmacogenetics in Hematopoietic Cell Transplantation Patients

We evaluated inosine monophosphate dehydrogenase (IMPDH) 1 and IMPDH2 pharmacogenetics in 247 recipient-donor pairs after nonmyeloablative hematopoietic cell transplant (HCT). Patients were conditioned with total body irradiation + fludarabine and received grafts from related or unrelated donors (10% HLA mismatch), with postgraft immunosuppression of mycophenolate mofetil (MMF) with a calcineurin inhibitor. Recipient and donor IMPDH genotypes (rs11706052, rs2278294, rs2278293) were not associated with day 28 T cell chimerism, acute graft-versus-host disease (GVHD), disease relapse, cytomegalovirus reactivation, nonrelapse mortality, or overall survival. Recipient IMPDH1 rs2278293 genotype was associated with a lower incidence of chronic GVHD (hazard ratio, .72; P = .008) in nonmyeloablative HCT recipients. Additional studies are needed to confirm these results with the goal of identifying predictive biomarkers to MMF that lower GVHD.

Patient-centered Outcomes with Concomitant Use of Proton Pump Inhibitors and Other Drugs

PURPOSE

We performed a systematic review of patient-centered outcomes after the concomitant use of proton pump inhibitors (PPIs) and other drugs.

METHODS

We searched 4 databases in July 2016 to find studies that reported mortality and morbidity after the concomitant use of PPIs and other drugs. We conducted direct meta-analyses using a random-effects model and graded the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation working group approach.

FINDINGS

We included data from 17 systematic reviews and meta-analyses, 16 randomized controlled trials, and 16 observational studies that examined the concomitant use of PPIs with medications from 10 drug classes. Low-quality evidence suggests that the use of PPIs is associated with greater morbidity when administered with antiplatelet drugs, bisphosphonates, antibiotics, anticoagulants, metformin, mycophenolate mofetil, or nelfinavir. Concomitant PPIs reduce drug-induced gastrointestinal bleeding and are associated with greater docetaxel and cisplatin response rates in patients with metastatic breast cancer. For demonstrated statistically significant relative risks and benefits from concomitant PPIs, the magnitudes of the effects are small, with <100 attributable events per 1000 patients treated, and the effects are inconsistent among specific drugs. Among individual PPIs, the concomitant use of pantoprazole or esomeprazole, but not omeprazole or lansoprazole, is associated with an increased risk for all-cause mortality, nonfatal myocardial infarction, or stroke. Clopidogrel is associated with a greater risk for myocardial infarction compared with prasugrel. Conflicting results between randomized controlled trials and observational studies and high risk for bias in the body of evidence lessened our confidence in the results.

IMPLICATIONS

Available evidence suggests a greater risk for adverse patient outcomes after the concomitant use of PPIs and medications from 9 drug classes and warns against inappropriate drug combinations.