Effect of omeprazole on the plasma concentrations of indinavir when administered alone and in combination with ritonavir

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.

An Open Label, Phase 1, Randomized, Seven-treatment, Seven-period, Crossover Study to Assess the Relative Bioavailability, pH Effect, Food Effect, and Dose Proportionality of CC-292, a Potent and Orally Available Bruton's Tyrosine Kinase Inhibitor

BACKGROUND AND OBJECTIVE

CC-292 is a potent, selective, orally administered small molecule inhibitor of Bruton's tyrosine kinase (BTK). To support the clinical investigation of CC-292, a randomized, seven-treatment, seven-period, crossover study was conducted to assess the relative bioavailability, pH effect, food effect, and dose-proportionality of two formulated tablets of CC-292.

METHODS

Healthy subjects (n = 24) were enrolled in the study and randomly assigned into different treatment sequences. Blood samples were collected at pre-specified time points to measure the drug concentrations in plasma. Statistical analyses were performed to compare the pharmacokinetics of CC-292 under different conditions.

RESULTS

The relative bioavailability of the newly developed formulation [spray-dried dispersion (SDD)] to the reference formulation (P22) was 1.24. When a single dose of CC-292 SDD tablet was administered under fed conditions, the area under the plasma concentration-time curve from time zero to infinity (AUC_∞) increased by 10.9% and the maximum plasma drug concentration C_max) decreased by 19.4% compared to when CC-292 was administered under fasted conditions. When a single dose of CC-292 SDD tablet was administered after multiple doses of omeprazole, the area under the plasma concentration-time curve from time zero to infinity (AUC_∞) decreased by 36.8% and the maximum plasma drug concentration C_max) decreased by 48.1% compared to when CC-292 was administered alone. Over a dose range of 100-300 mg (SDD formulation), CC-292 exhibited more than dose-proportional increases of drug exposures.

CONCLUSIONS

CC-292 was well tolerated when administered to healthy subjects as single oral doses under all conditions. Food intake had no clinically relevant impact on CC-292 pharmacokinetics compared to fasted conditions. Therefore, CC-292 can be administered with or without food. Co-administration of CC-292 with multiple doses of omeprazole (40 mg) decreased the pharmacokinetic exposure of CC-292. However, the effect was not clinically relevant.

CLINICAL TRIALS REGISTRATION

NCT02433457.

Drug-Drug Interactions With Over-The-Counter Medicines: Mind the Unprescribed

BACKGROUND

This review provides a summary of the currently available clinical data on drug-drug interactions (DDIs) involving over-the-counter (OTC) medicines. It aims to educate and increase awareness among health care providers and to support decisions in daily practice.

METHODS

An extensive literature search was performed using bibliographic databases available through PubMed.gov. An initial structured search was performed using the keywords "drug-drug-interaction AND (over-the-counter OR OTC)," without further restrictions except for the language. The initial results were screened for all described DDIs involving OTC drugs, and further information was gathered specifically on these drugs using dedicated database searches and references found in the bibliography from the initial hits.

RESULTS

From more than 1200 initial hits (1972-June 2021), 408 relevant publications were screened for DDIs involving OTC drugs, leading to 2 major findings: first, certain types of drug regimens are more prone to DDIs or have more serious DDI-related consequences, such as antiretroviral, anti-infective, and oral anticancer therapies. Second, although most DDIs involve OTC drugs as the perpetrators, some prescription drugs (statins or phosphodiesterase-5 inhibitors) that currently have OTC status can be identified as the victims in DDIs. The following groups were identified to be frequently involved in DDIs: nonsteroidal anti-inflammatory drugs, food supplements, antacids, proton-pump inhibitors, H2 antihistamines, laxatives, antidiarrheal drugs, and herbal drugs.

CONCLUSIONS

The most significant finding was the lack of high-quality evidence for commonly acknowledged interactions. High-quality interaction studies involving different phenotypes in drug metabolism (cytochrome P450) and distribution (transporters) are urgently needed. This should include modern and critical drugs, such as oral anticancer medications and direct oral anticoagulants.

Effects of medicines used to treat gastrointestinal diseases on the pharmacokinetics of coadministered drugs: a PEARRL Review

Objectives

Drugs used to treat gastrointestinal diseases (GI drugs) are widely used either as prescription or over-the-counter (OTC) medications and belong to both the 10 most prescribed and 10 most sold OTC medications worldwide. The objective of this review article is to discuss the most frequent interactions between GI and other drugs, including identification of the mechanisms behind these interactions, where possible.

Key findings

Current clinical practice shows that in many cases, these drugs are administered concomitantly with other drug products. Due to their metabolic properties and mechanisms of action, the drugs used to treat gastrointestinal diseases can change the pharmacokinetics of some coadministered drugs. In certain cases, these interactions can lead to failure of treatment or to the occurrence of serious adverse events. The mechanism of interaction depends highly on drug properties and differs among therapeutic categories. Understanding these interactions is essential to providing recommendations for optimal drug therapy.

Summary

Interactions with GI drugs are numerous and can be highly significant clinically in some cases. While alterations in bioavailability due to changes in solubility, dissolution rate, GI transit and metabolic interactions can be (for the most part) easily identified, interactions that are mediated through other mechanisms, such as permeability or microbiota, are less well-understood. Future work should focus on characterising these aspects.

Interindividual and intraindividual variability of fasted state gastric fluid volume and gastric emptying of water

The amount and composition of gastrointestinal media are crucial parameters in oral drug delivery. In fasted state, variable residual gastric volumes and gastric emptying behavior often cause variable drug release and absorption from oral drug products. Unfortunately, interindividual and intraindividual variability of the gastric conditions in fasted state are currently insufficiently mapped. In this work, datasets from 5 MRI studies with 16 treatments in total were pooled. The interindividual and intraindividual variability of residual gastric volumes after 10 h overnight fasting and the subsequent emptying of 240 mL of water were compared in healthy human subjects under conditions mimicking clinical studies. This work shows that even under standardized clinical conditions, residual gastric volumes and water emptying are highly variable. Interestingly, interindividual and intraindividual variabilities of both parameters were comparable, suggesting that the variability within the studies was mainly resulting from intraindividual day-to-day variations. The mean resting volumes in all conducted investigations amounted to 25 ± 18 mL (n = 120). Furthermore, 85 ± 13% (n = 22) of initially available gastric volume (resting volume plus 240 mL) was emptied after 30 min. The findings of this work will hopefully contribute to a better comprehension of the variability of oral drug release and absorption.

An Investigation of Oral Exposure Variability and Formulation Strategy: A Case Study of PI3Kδ Inhibitor and Physiologically Based Pharmacokinetic Modeling in Beagle Dogs

It is well acknowledged that drugs with poor aqueous solubility are often associated with poor oral absorption. Fortunately, drugs with a basic pKa can take advantage of solubilization in the stomach under the acidic environment to improve exposure. Consequently, high in vivo variability is often observed when stomach pH is altered. When issue encountered, enabling formulations are often used to solve the problem. However, each enabling formulation has its limitations and the situation can be further complicated by other absorption distribution metabolism elimination parameters. Therefore, formulation strategies need to consider various scenarios in order to be effective. Compound 1 is a potent phosphoinositide 3-kinase delta inhibitor with poor intrinsic solubility and 2 basic pKas. It was dosed as a suspension in dogs and found to have mediocre oral bioavailability with high variability. It was hypothesized that this variability was caused by their stomach pH variability. Pharmacokinetic modeling suggested that the issue could be improved with particle size reduction. Meanwhile, it was found that although the Madin-Darby canine kidney permeability was reasonable, Madin-Darby canine kidney transfected with human MDR1 gene (MDCK-MDR1) suggested that Compound 1 is an efflux transporter substrate. Findings were integrated into the design for in vivo studies in dogs. Data obtained from those studies allowed us to quickly narrow down the formulation approaches.

Pharmacokinetic drug interaction profiles of proton pump inhibitors: an update

Proton pump inhibitors (PPIs) are used extensively for the treatment of gastric acid-related disorders, often over the long term, which raises the potential for clinically significant drug interactions in patients receiving concomitant medications. These drug–drug interactions have been previously reviewed. However, the current knowledge is likely to have advanced, so a thorough review of the literature published since 2006 was conducted. This identified new studies of drug interactions that are modulated by gastric pH. These studies showed the effect of a PPI-induced increase in intragastric pH on mycophenolate mofetil pharmacokinetics, which were characterised by a decrease in the maximum exposure and availability of mycophenolic acid, at least at early time points. Post-2006 data were also available outlining the altered pharmacokinetics of protease inhibitors with concomitant PPI exposure. New data for the more recently marketed dexlansoprazole suggest it has no impact on the pharmacokinetics of diazepam, phenytoin, theophylline and warfarin. The CYP2C19-mediated interaction that seems to exist between clopidogrel and omeprazole or esomeprazole has been shown to be clinically important in research published since the 2006 review; this effect is not seen as a class effect of PPIs. Finally, data suggest that coadministration of PPIs with methotrexate may affect methotrexate pharmacokinetics, although the mechanism of interaction is not well understood. As was shown in the previous review, individual PPIs differ in their propensities to interact with other drugs and the extent to which their interaction profiles have been defined. The interaction profiles of omeprazole and pantoprazole sodium (pantoprazole-Na) have been studied most extensively. Several studies have shown that omeprazole carries a considerable potential for drug interactions because of its high affinity for CYP2C19 and moderate affinity for CYP3A4. In contrast, pantoprazole-Na appears to have lower potential for interactions with other medications. Lansoprazole and rabeprazole also seem to have a weaker potential for interactions than omeprazole, although their interaction profiles, along with those of esomeprazole and dexlansoprazole, have been less extensively investigated. Only a few drug interactions involving PPIs are of clinical significance. Nonetheless, the potential for drug interactions should be considered when choosing a PPI to manage gastric acid-related disorders. This is particularly relevant for elderly patients taking multiple medications, or for those receiving a concomitant medication with a narrow therapeutic index.

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.

[Adverse effects of proton pump inhibitors: should we worry about long-term exposure?]

Long-term treatment with proton pump inhibitors (PPI) is becoming more prevalent. Although they are well tolerated in the short term, serious concerns about long-term use have arisen. Recent data suggest that the latter is associated with an increased risk for osteoporotic fracture (especially vertebral), Clostridium difficile infection and rebound acid hypersecretion after treatment discontinuation. Acute interstitial nephritis is rare but may progress to chronic renal failure. An increased risk of community-acquired pneumonia has not been established in the general population and seems limited to the most vulnerable patients. Consistent data are still missing to correctly assess the risk of iron deficiency, vitamin B12 deficiency or hypomagnesaemia and the risk of digestive malignant diseases, despite the pathophysiological basis that exists concerning gastric malignancy. Many drug interactions can occur on long-term treatment, including some that imply the cytochrome P450 enzymes. Finally, the risk-benefit balance for a chronic PPI use in children seems unfavorable in most cases.

Antiretroviral drug interactions: overview of interactions involving new and investigational agents and the role of therapeutic drug monitoring for management

Antiretrovirals are prone to drug-drug and drug-food interactions that can result in subtherapeutic or supratherapeutic concentrations. Interactions between antiretrovirals and medications for other diseases are common due to shared metabolism through cytochrome P450 (CYP450) and uridine diphosphate glucuronosyltransferase (UGT) enzymes and transport by membrane proteins (e.g., p-glycoprotein, organic anion-transporting polypeptide). The clinical significance of antiretroviral drug interactions is reviewed, with a focus on new and investigational agents. An overview of the mechanistic basis for drug interactions and the effect of individual antiretrovirals on CYP450 and UGT isoforms are provided. Interactions between antiretrovirals and medications for other co-morbidities are summarized. The role of therapeutic drug monitoring in the detection and management of antiretroviral drug interactions is also briefly discussed.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

Evaluation of Continuation of Stress Ulcer Prophylaxis at Hospital Discharge

Purpose

Stress-related mucosal disease (SRMD) can adversely affect patient morbidity and mortality. The use of stress ulcer prophylaxis (SUP) in patients with no risk factors for clinically important bleeding, however, is contributing to health care-related adverse events, drug interactions, and costs. The objective was to determine the percentage of hospitalized patients who receive SUP without an approved indication and to evaluate the financial impact of inappropriate prescribing as well as the risk for significant drug-drug interactions.

Methods

A retrospective chart review was performed of hospitalized adult cardiology, family medicine, and internal medicine patients between July 1, 2006 and June 30, 2007. Prescribing of acid suppressive therapy (AST) during hospital admission and indications for SUP were evaluated. Concomitant medications, cost of therapy, and discharge medications were assessed as secondary outcomes.

Results

Of the 4,603 patients admitted during the study period, 418 were randomly selected for study inclusion. Approximately 53% (221/418) of the selected patients received SUP during hospital admission, 93% (206/221) of whom had no indication for prophylaxis. Of those who continued AST at discharge (14%; 31/221), 84% (26/31) had no approved indication. Overuse of SUP resulted in 77 potential drug-drug interactions and an estimated 30-day outpatient cost of $37,950 for patients receiving these medications at discharge.

Conclusion

SUP is frequently prescribed to non–critically ill patients when the risk of SRMD is low. Use of SUP for patients who do not meet evidence-based criteria appears to contribute to increased health care expenditures, potential adverse events, and drug interactions.

A pharmacokinetic study of etravirine (TMC125) co-administered with ranitidine and omeprazole in HIV-negative volunteers

AIMS

Etravirine is a next-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) with activity against wild-type and NNRTI-resistant HIV. Proton pump inhibitors and H(2)-antagonists are frequently used in the HIV-negative-infected population, and drug-drug interactions have been described with other antiretrovirals. This study evaluated the effect of steady-state omeprazole and ranitidine on the pharmacokinetics of a single dose of etravirine.

METHODS

In an open-label, randomized, one-way, three-period crossover trial, HIV-negative volunteers randomly received a single dose of 100 mg etravirine alone (treatment A); 11 days of 150 mg ranitidine b.i.d. (treatment B); and 11 days of 40 mg omeprazole q.d. (treatment C). A single dose of 100 mg etravirine was co-administered on day 8 of sessions 2 and 3. Each session was separated by a 14-day wash-out.

RESULTS

Nineteen volunteers (seven female) participated. When a single dose of etravirine was administered in the presence of steady-state ranitidine, etravirine least squares means ratios (90% confidence interval) for AUC(last) and C(max) were 0.86 (0.76, 0.97) and 0.94 (0.75, 1.17), respectively, compared with administration of etravirine alone. When administered with steady-state omeprazole, these values were 1.41 (1.22, 1.62) and 1.17 (0.96, 1.43), respectively. Co-administration of a single dose of etravirine and ranitidine or omeprazole was generally safe and well tolerated.

CONCLUSIONS

Ranitidine slightly decreased etravirine exposure, whereas omeprazole increased it by approximately 41%. The increased exposure of etravirine when co-administered with omeprazole is attributed to CYP2C19 inhibition. Considering the favourable safety profile of etravirine, these changes are not clinically relevant. Etravirine can be co-administered with proton pump inhibitors and H(2) antagonists without dose adjustments.