Diminished Mycophenolic Acid Exposure Caused by Omeprazole May Be Clinically Relevant in the First Week Posttransplantation

Comparing safety of proton-pump inhibitors versus H2-receptor antagonists in kidney transplant recipients: A systematic review and meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Multiple studies have been conducted to compare the safety of proton-pump inhibitors (PPIs) and H2-receptor antagonists (H2RAs) as acid-suppressive treatment in kidney transplant recipients with conflicting results. This systematic review and meta-analysis aimed to evaluate the risk of adverse effects in kidney transplant patients receiving PPIs compared to those treated with H2RAs.

METHODS

A systematic search was performed on the databases from inception to June 2021. The treatment effects were expressed as odds ratio (OR), weighted mean differences (WMD) and their 95% confidence intervals (CI) and pooled by a random-effects model.

RESULTS AND DISCUSSIONS

Eight studies, consisting 4,844 patients, were included. Patients were followed for a mean duration of 23.57 months after transplantation. Compared with H2RAs, PPIs exposure was associated with similar rate of biopsy-proven acute rejection (BPAR) (OR = 1.05, 95% CI 0.83-1.34, p = 0.67), mortality (OR = 1.31, 95% CI 0.56-3.07, p = 0.533), graft loss (OR = 1.06, 95% CI 0.59-1.93, p = 0.842), Clostridioides difficile infection (OR = 1.37, 95% CI 0.49-3.85, p = 0.545) and pneumonia (OR = 1.83, 95% CI 0.95-3.52, p = 0.072). The estimated glomerular filtration rate (eGFR) at 12 months was lower in patients who received PPIs than those treated with H2RAs (WMD = -1.01, 95% CI -1.89 to -0.12 ml/min/1.73m² , p = 0.02). The PPI-treated kidney transplant patients experienced higher rate of antibody-mediated rejection (AMR) (OR = 1.87, 95% CI 1.03-3.04, p = 0.039) and hypomagnesemia (OR = 2.16, 95% CI 1.46-3.20, p ˂ 0.001).

WHAT IS NEW AND CONCLUSIONS

Compared with H2RAs, PPIs were not associated with higher risks of BPAR, mortality, graft loss or infection-related outcomes. However, taking PPIs was associated with higher rates of AMR and hypomagnesemia, and lower eGFR at one year after transplantation. Further well-controlled studies are needed to assess the impact of acid-suppressive strategy on long-term outcomes in KTRs.

The impact of omeprazole on mycophenolate pharmacokinetics in kidney transplant recipients

Background

The absorption rates of mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS) may be influenced by the concomitant use of omeprazole.

Methods

One hundred kidney transplant patients were recruited during their outpatient visits, including 50 on MMF and 50 on EC-MPS. At the clinic, a predose mycophenolic acid (MPA) sample (C0) was collected; subsequently, the participants received the proton-pump inhibitor omeprazole along with either MMF or EC-MPS. Two more blood samples were collected at 1.5 and 3.5 hours and used to estimate an area under the curve (AUC) from zero to 12 hours [AUC (0-12)].

Results

The mean number of months after transplant was 92 months. The median AUC (0-12) and C0 results were 62.2 mg·h/L and 2.0 mg/L for the MMF group and 71.9 mg·h/L and 1.8 mg/L for the EC-MPS group (P = 0.160 and 0.225, respectively). Interestingly, 54% of the MMF group and 62% of the EC-MPS group showed AUCs above the target values. The correlation between MPA C0 and the predicted AUC was poor in both groups.

Conclusion

Omeprazole can be safely co-administered with either MMF or EC-MPS, as it did not compromise the MPA exposure. Unexpectedly, however, a high percentage of patients presented MPA AUCs exceeding the target value, highlighting the importance of periodically assessing MPA level.

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.

Safety assessment of omeprazole use: a review

BACKGROUND

Risks regarding hospital admission due to adverse drug reactions and drug interactions from use of omeprazole have been reported. The question guiding the present review was "Which adverse events occur in patients using omeprazole in a Food and Drug Administration-approved and/or off-label manner?" It was also proposed to evaluate the safety of use of omeprazole.

DESIGN AND SETTING

Qualitative narrative review with critical evaluation, in a public university.

METHODS

The PubMed, SCOPUS, LILACS, SciELO, EMBASE and EBSCO databases were searched on July 31, 2018. Studies evaluating adverse events were screened.

RESULTS

72 articles were included, among which 58 reported on adverse drug events (47, adverse drug reactions; 5, drug interactions; and 6, situations of ineffectiveness). 28 adverse drug reactions not described in compendia and drug leaflets were described in these studies: myocardial infarction (6); stroke (2); spontaneous abortion (1); proliferative changes (1); chills (1); heart failure (1); thrombosis (2); and dementia (1), among others. Severe adverse reactions, for instance cardiac problems, Steven-Johnson syndrome and proliferative changes, were identified. The antiplatelet effects of drugs such as clopidogrel, in patients who underwent heart-related surgery, increased the risk of developing cardiac problems, such as cardiovascular death, myocardial infarction and stroke. In newly transplanted patients, decreased absorption of mycophenolate mofetil occurred, thus leading to rejection of transplanted organs.

CONCLUSION

Use of omeprazole should be monitored primarily in patients with heart disorders using antiplatelet agents concomitantly, and in newly transplanted patients using mycophenolic acid, in order to avoid serious adverse reactions.

Routine prophylaxis with proton pump inhibitors and post-transplant complications in kidney transplant recipients undergoing early corticosteroid withdrawal

Surgical stress, corticosteroids, and mycophenolate may contribute to gastrointestinal ulcers/bleeding after kidney transplantation. Prophylactic acid suppression with H2RAs or PPIs is often utilized after transplantation, although unclear if truly indicated after early corticosteroid withdrawal (CSWD). PPIs have been associated with increased risks of Clostridium difficile infection (CDI), pneumonia, and acute rejection. This retrospective cohort study investigated benefits and risks of prolonged PPI use following kidney transplantation and included 286 kidney recipients undergoing CSWD within five d of transplant who were maintained on tacrolimus and mycophenolate mofetil/sodium. Patients on PPI before transplant, H2RA before/after transplant, and/or those with pre-transplant GI complications were excluded. A total of 171 patients received PPI>30 d, mean duration 287 ± 120 d (PPI group); 115 patients were not maintained on acid suppression (No-PPI group). GI ulceration and bleeding events were rare in PPI group (1.2% and 2.3%, respectively) and not observed in No-PPI group (p = NS). The incidence of infectious or hematological complications was not significantly different between groups. The PPI group experienced more biopsy-proven acute rejection (9.4% vs. 2.6%, p = 0.03). No direct benefit was observed with PPI in reducing the incidence of GI ulcers and bleeding events in kidney transplant recipients undergoing early CSWD. Further studies are needed to investigate the association of PPI and acute rejection.

Pharmacokinetic drug interaction profile of omeprazole with adverse consequences and clinical risk management

BACKGROUND

Omeprazole, a proton pump inhibitor (PPI), is widely used for the treatment of dyspepsia, peptic ulcer, gastroesophageal reflux disease, and functional dyspepsia. Polypharmacy is common in patients receiving omeprazole. Drug toxicity and treatment failure resulting from inappropriate combination therapy with omeprazole have been reported sporadically. Systematic review has not been available to address the pharmacokinetic drug-drug interaction (DDI) profile of omeprazole with adverse consequences, the factors determining the degree of DDI between omeprazole and comedication, and the corresponding clinical risk management.

METHODS

Literature was identified by performing a PubMed search covering the period from January 1988 to March 2013. The full text of each article was critically reviewed, and data interpretation was performed.

RESULTS

Omeprazole has actual adverse influences on the pharmacokinetics of medications such as diazepam, carbamazepine, clozapine, indinavir, nelfinavir, atazanavir, rilpivirine, methotrexate, tacrolimus, mycophenolate mofetil, clopidogrel, digoxin, itraconazole, posaconazole, and oral iron supplementation. Meanwhile, low efficacy of omeprazole treatment would be anticipated, as omeprazole elimination could be significantly induced by comedicated efavirenz and herb medicines such as St John's wort, Ginkgo biloba, and yin zhi huang. The mechanism for DDI involves induction or inhibition of cytochrome P450, inhibition of P-glycoprotein or breast cancer resistance protein-mediated drug transport, and inhibition of oral absorption by gastric acid suppression. Sometimes, DDIs of omeprazole do not exhibit a PPI class effect. Other suitable PPIs or histamine 2 antagonists may be therapeutic alternatives that can be used to avoid adverse consequences. The degree of DDIs associated with omeprazole and clinical outcomes depend on factors such as genotype status of CYP2C19 and CYP1A2, ethnicity, dose and treatment course of precipitant omeprazole, pharmaceutical formulation of object drug (eg, mycophenolate mofetil versus enteric-coated mycophenolate sodium), other concomitant medication (eg, omeprazole-indinavir versus omeprazole-indinavir-ritonavir), and administration schedule (eg, intensified dosing of mycophenolate mofetil versus standard dosing).

CONCLUSION

Despite the fact that omeprazole is one of the most widely prescribed drugs internationally, clinical professionals should enhance clinical risk management on adverse DDIs associated with omeprazole and ensure safe combination use of omeprazole by rationally prescribing alternatives, checking the appropriateness of physician orders before dispensing, and performing therapeutic drug monitoring.

Lack of a clinically significant drug-drug interaction in healthy volunteers between the HCV protease inhibitor boceprevir and the proton pump inhibitor omeprazole

OBJECTIVES

Proton pump inhibitors (PPIs) can limit the solubility of concomitant drugs, which can lead to decreased absorption and exposure. Reduced efficacy can be a consequence and in the case of an antimicrobial agent this may contribute to development of resistance. Patients chronically infected with the hepatitis C virus can be treated with a boceprevir-containing regimen and it is relevant to know if interactions between PPIs and boceprevir exist. This study was designed to investigate the influence of a frequently used PPI, omeprazole, on the pharmacokinetics of boceprevir and vice versa.

METHODS

In this open-label, three-period, randomized, cross-over, Phase I study, healthy subjects were randomly assigned to 40 mg of omeprazole once daily for 5 days, 800 mg of boceprevir three times daily for 5 days and 40 mg of omeprazole once daily + 800 mg of boceprevir three times daily for 5 days, or the same treatment in a different order. Every treatment was followed by a wash-out period. At day 5 of every treatment pharmacokinetic blood sampling was performed for 8 h after medication intake. ClinicalTrials.gov: NCT01470690.

RESULTS

All 24 subjects (15 males) completed the study and no serious adverse events were reported. Geometric mean ratios (90% CI) of the area under the plasma concentration-time curve up to 8 h (AUC0-8) and maximum plasma concentration (Cmax) of boceprevir with omeprazole versus boceprevir alone were 0.92 (0.87-0.97) and 0.94 (0.86-1.02), respectively. For omeprazole these values were 1.06 (0.90-1.25) for AUC0-8 and 1.03 (0.85-1.26) for Cmax for the combination versus omeprazole alone.

CONCLUSIONS

Omeprazole did not have a clinically significant effect on boceprevir exposure, and boceprevir did not affect omeprazole exposure.