Comparative risk of ischemic stroke among users of clopidogrel together with individual proton pump inhibitors

Safety of Combined Statin and Fibrate Therapy: Risks of Liver Injury and Acute Kidney Injury in a Cohort Study from the Shizuoka Kokuho Database

INTRODUCTION

Statins and fibrates are important means of preventing cardiovascular diseases, particularly when administered in combination as part of various therapeutic strategies. In this study, we explored the risks associated with various combinations of these drugs.

OBJECTIVE

We aimed to evaluate the risk of 1-year hospitalization with acute kidney injury, liver injury, pancreatitis, or rhabdomyolysis related to the concurrent administration of statins and fibrates.

METHODS

We performed a retrospective cohort study using data from the Shizuoka Kokuho Database, focusing on patients prescribed statins, fibrates, or a combination. Four drug exposure patterns were evaluated: adding statins to fibrates (exposure 1), switching from fibrates to statins (exposure 2), adding fibrates to statins (exposure 3), and switching from statins to fibrates (exposure 4). Hospitalization for the specified conditions within 1 year was the outcome. Propensity score matching was used to create balanced cohorts for comparison.

RESULTS

We studied 269,226 statin users and 16,282 fibrate users. After propensity score matching, there were 498 participants in the group of exposure 1, matched with 2988 in the fibrate-only group; 1180 in the group of exposure 2, matched with 7080 in the fibrate-only group; 1183 in group of exposure 3, matched with 11,830 in the statin only group; and 1356 in group of exposure 4, matched with 13,560 in the statin only group. The 1-year hospitalization rate with liver injury was higher in the group of exposure 1 than in the fibrate-only group (1.2% vs 0.3%, p < 0.01), in the group of exposure 2 than in the fibrate-only group (0.9% vs 0.3%, p < 0.01), and in the group of exposure 4 than in the statin-only group (0.6% vs 0.2%, p = 0.02). There was also a higher risk of 1-year hospitalization with acute kidney injury in group of exposure 1 than in the fibrate-only group (1.3% vs 0.3%, p = 0.01) but not in evaluations of exposure 2, 3, and 4. However, there were no differences in the risks of 1-year hospitalization with pancreatitis or rhabdomyolysis among the matched groups.

CONCLUSIONS

We have demonstrated higher risks of 1-year hospitalization with liver injury or acute kidney injury associated with the use of combinations of statins and fibrates. This underscores the need for a cautious approach to the prescribing of such drug combinations and the importance of monitoring patients for potential adverse events.

Gastric cancer risk in the elderly is associated with omeprazole use and inversely associated with aspirin use

BACKGROUND

The association between long-term omeprazole use and gastric cancer (GC) risk is controversial. The aim of this study was to investigate the incidence of GC in elderly community-dwelling omeprazole chronic users with/without aspirin compared to non-users.

METHODS

The registry of a large health management organization was searched for all community-dwelling members aged ≥65 years from January 2002 to December 2016. Data on demographics, background parameters, and chronic omeprazole and aspirin use (>11 prescriptions/year) were retrieved. Those diagnosed with new-onset GC during the study period (from January 2003) were identified.

RESULTS

Of 51 405 subjects who met the inclusion criteria, 197 were diagnosed with GC during a mean follow-up period of 8.74 ± 4.16 years. This group accounted for 0.7% of PPI chronic users (72/11 008) and 0.3% (125/40 397) of nonusers (P < 0.001). GC risk was directly associated with omeprazole chronic use [hazard ratio (HR) 2.03, 95% confidence interval (CI): 1.51-2.73, P < 0.001] and inversely associated with aspirin chronic use (HR 0.55, 95% CI: 0.40-0.75, P < 0.001). Each year of omeprazole use increased GC risk by 9%, and each year of aspirin use decreased GC risk by 10% among omeprazole chronic users. The lowest rate of GC was found in omeprazole nonusers/ aspirin chronic users, and the highest, in omeprazole chronic users/aspirin nonusers.

CONCLUSION

Higher GC rate was associated with omeprazole chronic use and inversely associated with aspirin chronic use relative to omeprazole nonuse in community-dwelling elderly.

Prevalence and Safety of Prescribing PPIs with Clopidogrel in Palestine

BACKGROUND

Proton pump inhibitors (PPIs) are commonly prescribed medications that are thought to increase the risk of cardiovascular events because they reduce the effectiveness of clopidogrel via shared hepatic pathways.

OBJECTIVE

This study examined the prevalence of concomitant prescribing of clopidogrel/PPI among patients diagnosed with acute coronary syndrome and the adverse cardiovascular event associated with this interaction.

METHODS

A retrospective cohort study was conducted by retrieving patient data from the Nat Health Insurance claims processor database in Palestine. Adults diagnosed with Acute Coronary Syndrome (ACS) from 2019 through 2021 who were prescribed clopidogrel or clopidogrel in combination with a PPI were included in the study. Endpoints were adverse cardiac events, including readmission for revascularization during the first year of treatment.

RESULTS

The study included 443 patients; the prevalence of prescribing concomitant clopidogrel with a PPI was 74.7%, whereas 49.2% were prescribed interacting PPI (omeprazole, esomeprazole, and lansoprazole). 59 (13.3%) of participants experienced a cardiovascular event within 1 year of starting therapy, including 27 (12.4%) patients who had a cardiovascular event while taking an interacting PPI. No significant association was found between PPI administration and increased CV event risk in patients receiving concomitant clopidogrel and PPIs therapy (p = 0.579).

CONCLUSION

In this study, we observed a high prevalence of prescribing a PPI in combination with clopidogrel, regardless of the FDA recommendations. No significant increase in cardiovascular events was observed in patients receiving concomitant clopidogrel and PPI therapy.

Thromboembolic Events in Users of Warfarin Treated with Different Skeletal Muscle Relaxants

Background and Objectives: Warfarin and a skeletal muscle relaxant are co-treatments in nearly a quarter-million annual United States (US) office visits. Despite international calls to minimize patient harm arising from anticoagulant drug interactions, scant data exist on clinical outcomes in real-world populations. We examined effects of concomitant use of warfarin and individual muscle relaxants on rates of hospitalization for thromboembolism among economically disadvantaged persons. Materials and Methods: Using 1999−2012 administrative data of four US state Medicaid programs, we conducted 16 retrospective self-controlled case series studies: half included concomitant users of warfarin + one of eight muscle relaxants; half included concomitant users of an inhaled corticosteroid (ICS) + one of eight muscle relaxants. The ICS analyses served as negative control comparisons. In each study, we calculated incidence rate ratios (IRRs) comparing thromboembolism rates in the co-exposed versus warfarin/ICS-only exposed person-time, adjusting for time-varying confounders. Results: Among ~70 million persons, we identified 8693 warfarin-treated subjects who concomitantly used a muscle relaxant, were hospitalized for thromboembolism, and met all other inclusion criteria. Time-varying confounder-adjusted IRRs ranged from 0.31 (95% confidence interval: 0.13−0.77) for metaxalone to 3.44 (95% confidence interval: 1.53−7.78) for tizanidine. The tizanidine finding was robust after quantitatively adjusting for negative control ICS findings, and in numerous prespecified secondary analyses. Conclusions: We identified a potential >3-fold increase in the rate of hospitalized thromboembolism in concomitant users of warfarin + tizanidine vs. warfarin alone. Alternative explanations for this finding include confounding by indication, a native effect of tizanidine, or chance.

An update on drug-drug interactions associated with proton pump inhibitors

INTRODUCTION

Proton pump inhibitors (PPIs) block the gastric H/K-ATPase, therefore inhibiting acid gastric secretion, leading to an increased pH (>4). They account for an extremely high number of prescriptions worldwide. Numerous drug-drug interactions have been described with PPIs, but all the described interactions do not have clinical significance.

AREAS COVERED

This review will discuss the latest updates on drug-drug interactions with PPIs, focusing on the last ten-year publications in the following areas: anti-infective agents, anticancer drugs, antiplatelet agents and anticoagulants, and antidiabetics.

EXPERT OPINION

Although pharmacokinetic interactions of PPIs have been described with many drugs, their clinical relevance remains controversial. However, given the extremely high number of people being treated with PPIs, clinicians should remain vigilant for interactions that may be clinically significant and require dose adjustment or therapeutic monitoring. Interestingly, not all PPIs have the same pharmacokinetic and pharmacodynamic profile, with some having a strong potential to inhibit CYP2C19, such as omeprazole, esomeprazole and lansoprazole, while others, pantoprazole, rabeprazole and dexlansoprazole, are weak CYP2C19 inhibitors. These may be preferred depending on co-prescribed treatments.In addition, new formulations have been developed to prevent some of the gastric pH-dependent drug interactions and should be evaluated in further large-scale prospective comparative studies.

Regular use of proton-pump inhibitors and risk of stroke: a population-based cohort study and meta-analysis of randomized-controlled trials

BACKGROUND

Although randomized controlled trials (RCTs) have suggested a non-significant increased risk of stroke among proton pump inhibitor (PPI) users, the association has not been confirmed. We evaluated the association between regular use of PPIs and incident stroke and identified population groups at high net risk.

METHODS

This is a prospective analysis of 492,479 participants free of stroke from the UK biobank. Incident stroke was identified through linkage to hospital admission and death registries using the International Classification of Diseases (ICD)-10 codes (I60, I61, I63, and I64). We evaluated hazard ratios (HRs) adjusting for demographic factors, lifestyle habits, prevalent comorbidities, concomitant use of medications, and indications of PPIs. We assessed the risk differences (RDs) according to the baseline Framingham Stroke Risk Score. In the meta-analysis, we searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (from 1988 to 1 June 2020) for randomized trials comparing PPIs with other interventions, placebo, or no treatment on stroke risk. Results were combined using a fix-effect meta-analysis (Mantel-Haenszel method).

RESULTS

We documented 5182 incident strokes over 3,935,030 person-years of follow-up. Regular PPI users had a 16% higher risk of stroke than non-users (HR 1.16, 95% CI 1.06 to 1.27). The estimated effect was similar to our meta-analysis of nine RCTs (case/participants 371/26,642; RR 1.22, 95% CI 1.00 to 1.50; quality of evidence: moderate). The absolute effect of PPI use on stroke increased with the baseline Framingham Stroke Risk Score, with an RD of 1.34‰, 3.32‰, 4.83‰, and 6.28‰ over 5 years for the lowest, quartile 2, quartile 3, and the highest quartile, respectively.

CONCLUSIONS

Regular use of PPIs was associated with an increased risk of stroke, with a higher absolute risk observed in individuals with high baseline stroke risk. Physicians should therefore exercise caution when prescribing PPIs. An assessment of the underlying stoke risk is recommended for individualized use of PPIs.

Use of proton pump inhibitors is associated with lower rates of first-time ischemic stroke in community-dwelling elderly

AIM

Data on cardiovascular outcomes in elderly using proton pump inhibitors (PPI) are scant. We aimed to test the association between PPI use and the occurrence of first-time ischemic stroke (FTIS) among elderly.

METHODS

The electronic database of a centrally located district branch of a large health maintenance organization in Israel was retrospectively screened (2002-2016) for community-dwelling individuals (≥65-95 years) for demographics and co-morbidities. Follow-up was until FTIS, death or end of study. Findings were analyzed by PPI use and occurrence of FTIS.

RESULTS

29,639 subjects (without history of stroke and use of antiplatelet aggregation drugs) mean age of 82.2 ± 5.5 years (range: 65-95 years, 38% male) were analyzed: 8,600 (29%) used PPIs. Mean follow up was 10.58 years (SD ± 5.44). Similar total and annual occurrence rates of FTIS were depicted in PPI users and non-users (20.9% vs. 21% and 2% vs. 2.1%, respectively). On a Cox regression analysis, upon adjustment for age, gender and cardiovascular disease related risk factors, PPI use was significantly associated with lower rates of FTIS (HR 0.73, 95% C.I. 0.69-0.77, p < 0.001). The risk for FTIS was significantly lower in subjects using PPI at any dose and for any time period compared to non-users (HR 0.9, 95% C.I. 0.85-0.96 for 7-48 yearly prescriptions and HR 0.51, 95% C.I. 0.46-0.55 for ≥49 yearly prescriptions).

CONCLUSIONS

PPI use was associated with lower rates of FTIS in community-dwelling elders. Prospective large-scale studies are needed to fully elucidate the effect of PPI in this aging population.

The Case-Crossover Design for Drug-Drug Interactions: Considerations for Implementation

BACKGROUND

The case-crossover design may be useful for evaluating the clinical impact of drug-drug interactions in electronic healthcare data; however, experience with the design in this context is limited.

METHODS

Using US healthcare claims data (1994-2013), we evaluated two examples of interacting drugs with prior evidence of harm: (1) cytochrome P450 (CYP)3A4-metabolized statins + clarithromycin or erythromycin and rhabdomyolysis; and (2) clopidogrel + fluoxetine or fluvoxamine and ischemic events. We conducted case-crossover analyses with (1) a three-parameter model with a product term and a six-parameter saturated model that distinguished initiation order of the two drugs; and (2) with or without active comparators.

RESULTS

In the statin example, the three-parameter model produced estimates consistent with prior evidence with the active comparator (product term odds ratio [OR] = 2.05, 95% confidence interval [CI] = 1.00, 4.23) and without (OR = 1.99, 95% CI = 1.04, 3.81). In the clopidogrel example, this model produced results opposite of expectation (OR = 0.78, 95% = 0.68, 0.89), but closer to what was observed in prior studies when active comparator was used (OR = 1.03, 95% CI = 0.90, 1.19). The saturated model revealed heterogeneity of estimates across strata and considerable confounding; strata with concordant clopidogrel exposure likely produced the least biased estimates.

CONCLUSION

The three-parameter model assumes a common drug-drug interaction effect, whereas the saturated model is useful for identifying potential effect heterogeneity or differential confounding across strata. Restriction to certain strata or use of an active comparator may be necessary in the presence of within-person confounding.

Outcome of stroke patients on clopidogrel plus proton-pump inhibitors: a single-center cohort study

BACKGROUND

Recent studies suggest a higher risk of adverse cardiovascular outcome and mortality in patients co-prescribed clopidogrel with proton pump inhibitors (PPI).

OBJECTIVE

Investigate the impact of concomitant prescription of clopidogrel and PPI on 30-day unplanned readmission and one-year all-cause mortality.

DESIGN

Retrospective longitudinal cohort study.

SETTING

Single academic tertiary center.

PATIENTS AND METHODS

The study included patients admitted with a diagnosis of ischemic or hemorrhagic stroke between 2010 and 2014. Demographic and outcome data were collected and compared for patients on clopidogrel plus PPI vs those on clopidogrel plus H2blockers and those not on clopidogrel.

MAIN OUTCOME MEASURES

One-year mortality and 30-day unplanned readmissions were compared among different patient groups using multivariable logistic regression modeling.

SAMPLE SIZE

464 patients.

RESULTS

Out of 464 patients, 175 (37.7%) were discharged on clopidogrel. The concomitant prescription of clopidogrel and PPI was noted in 107 (24.4%) and clopidogrel and H2 blockers in 36 patients (7.8%). The one-year all-cause mortality in the entire cohort was 22.2%. Patients on clopidogrel plus PPI did not have a higher risk of one-year mortality compared to the non-PPI cohort (6.2% vs. 4.8%, p 0.7). There was a non-significant suggestion of lower one-year mortality in patients on clopidogrel plus PPI vs those not on clopidogrel (6.2% vs. 10.1%, p 0.23). In multivariable logistic regression, the use of clopidogrel plus PPI did not predict higher one-year mortality (odds ratio 0.6, P=0.6). The risk of unplanned 30-day readmission was lower in those with clop-idogrel plus PPI (odds ratio 0.6, P=.03).

CONCLUSION

The use of clopidogrel plus PPI resulted in lower readmission rates and was not associated with higher mortality compared with the non-PPI cohorts.

LIMITATIONS

Single center study, not generalizable. Given the retrospective nature of this study, we did not collect data on duration of treatments or patient compliance.

CONFLICT OF INTEREST

None.

No Significant Association Between Proton Pump Inhibitor Use and Risk of Stroke After Adjustment for Lifestyle Factors and Indication

BACKGROUND & AIMS

Proton pump inhibitors (PPI) are among the top 10 most prescribed medications worldwide. We investigated the association between PPI use and ischemic stroke.

METHODS

We collected data on 68,514 women (mean age, 65 ± 7 years) enrolled in the Nurses' Health Study since 2000 and 28,989 men (mean age, 69 ± 8 years) in the Health Professionals Follow-up Study since 2004, without a history of stroke. We used Cox proportional hazards models to examine the association between risk of incident stroke and PPI use among participants. The primary end point was first incident stroke.

RESULTS

In the 2 cohorts, we documented 2599 incident strokes (2037 in women and 562 in men) over a 12-year period, encompassing 949,330 person-years. After adjustment for established risk factors for stroke, PPI use was associated with a significant increase in risk of ischemic stroke (hazard ratio, 1.18; 95% confidence interval, 1.02-1.37). The association was reduced after we adjusted for potential indications for PPI use, including history of peptic ulcer disease, gastroesophageal reflux disease, or gastrointestinal bleeding, and prior use of histamine-2 receptor antagonist therapy (hazard ratio, 1.08; 95% confidence interval, 0.91-1.27). Regular PPI use was not associated with increased risk of stroke overall or hemorrhagic stroke.

CONCLUSIONS

In an analysis of data from the Nurses' Health Study and the Health Professionals Follow-up Study, we did not find a significant association between PPI use and ischemic stroke, after accounting for indications for PPI use. Prior reports of an increased risk of stroke may be due to residual confounding related to chronic conditions associated with PPI use.

Cerebrovascular Outcomes With Proton Pump Inhibitors and Thienopyridines: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Pharmacokinetic and prior studies on thienopyridine and proton pump inhibitors (PPI) coadministration provide conflicting data for cardiovascular outcomes, whereas there is no established evidence on the association of concomitant use of PPI and thienopyridines with adverse cerebrovascular outcomes.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials and cohort studies from inception to July 2017, reporting following outcomes among patients treated with thienopyridine and PPI versus thienopyridine alone (1) ischemic stroke, (2) combined ischemic or hemorrhagic stroke, (3) composite outcome of stroke, myocardial infarction (MI), and cardiovascular death, (4) MI, (5) all-cause mortality, and (6) major or minor bleeding events. After the unadjusted analyses of risk ratios, we performed additional analyses of studies reporting hazard ratios adjusted for potential confounders.

RESULTS

We identified 22 studies (12 randomized controlled trials and 10 cohort studies) comprising 131 714 patients. Concomitant use of PPI with thienopyridines was associated with increased risk of ischemic stroke (risk ratio, 1.74; 95% confidence interval [CI], 1.41-2.16; P<0.001), composite stroke/MI/cardiovascular death (risk ratio, 1.14; 95% CI, 1.01-1.29; P=0.04), and MI (risk ratio, 1.19; 95% CI, 1.00-1.40; P=0.05). Likewise, in adjusted analyses concomitant use of PPI with thienopyridines was again associated with increased risk of stroke (hazard ratios adjusted, 1.30; 95% CI, 1.04-1.61; P=0.02), composite stroke/MI/cardiovascular death (hazard ratios adjusted, 1.23; 95% CI, 1.03-1.47; P=0.02), but not with MI (hazard ratios adjusted, 1.19; 95% CI, 0.93-1.52; P=0.16).

CONCLUSIONS

Co-prescription of PPI and thienopyridines increases the risk of incident ischemic strokes and composite stroke/MI/cardiovascular death. Our findings corroborate the current guidelines for PPI deprescription and pharmacovigilance, especially in patients treated with thienopyridines.

Thromboembolic and neurologic sequelae of discontinuation of an antihyperlipidemic drug during ongoing warfarin therapy

Warfarin and antihyperlipidemics are commonly co-prescribed. Some antihyperlipidemics may inhibit warfarin deactivation via the hepatic cytochrome P450 system. Therefore, antihyperlipidemic discontinuation has been hypothesized to result in underanticoagulation, as warfarin metabolism is no longer inhibited. We quantified the risk of venous thromboembolism (VTE) and ischemic stroke (IS) due to statin and fibrate discontinuation in warfarin users, in which warfarin was initially dose-titrated during ongoing antihyperlipidemic therapy. Using 1999-2011 United States Medicaid claims among 69 million beneficiaries, we conducted a set of bidirectional self-controlled case series studies-one for each antihyperlipidemic. Outcomes were hospital admissions for VTE/IS. The risk segment was a maximum of 90 days immediately following antihyperlipidemic discontinuation, the exposure of interest. Time-varying confounders were included in conditional Poisson models. We identified 629 study eligible-persons with at least one outcome. Adjusted incidence rate ratios (IRRs) for all antihyperlipidemics studied were consistent with the null, and ranged from 0.21 (0.02, 2.82) for rosuvastatin to 2.16 (0.06, 75.0) for gemfibrozil. Despite using an underlying dataset of millions of persons, we had little precision in estimating IRRs for VTE/IS among warfarin-treated persons discontinuing individual antihyperlipidemics. Further research should investigate whether discontinuation of gemfibrozil in warfarin users results in serious underanticoagulation.

Proton-Pump Inhibitor Use and the Risk of First-Time Ischemic Stroke in the General Population: A Nationwide Population-Based Study

OBJECTIVES

An increased risk of adverse cardiovascular events was reported for concomitant use of proton-pump inhibitors (PPIs) in patients taking antiplatelet agents. The present study aimed at determining whether PPI use alone could be associated with first-time ischemic stroke.

METHODS

This was a retrospective nationwide study using database from Taiwan National Health Insurance and involved subjects aged ≥20 years. In propensity score-matched analysis, patients with current PPI use were compared with propensity score-matched PPI non-use controls at a 1:1 ratio. Patients with prior stroke or hospitalization before the index date were excluded. The primary outcome measure was hospitalization with a primary diagnosis of ischemic stroke during 120-day follow-up. A parallel analysis adopting a nested case-control design was carried out. Patients hospitalized for a first-time ischemic stroke were identified and were compared with matched controls using conditional logistic regression analyses focusing on PPI use before the index date.

RESULTS

The propensity score-matched analysis included 198,148 PPI treatment courses and control periods without PPI use. PPI use was associated with a higher risk of hospitalization due to ischemic stroke with a hazard ratio of 1.36 (95% confidence interval (CI) 1.14-1.620, P=0.001). Based on subgroup analysis, patients aged <60 years were more susceptible (P=0.043 for interaction), whereas gender, history myocardial infarction, diabetes mellitus, hypertension, use of antiplatelet agents of non-steroidal anti-inflammatory drugs, or type of PPIs had no effect on the risk. In the nested case-control analysis, 15,378 patients hospitalized owing to ischemic stroke were identified and were compared with 15,378 matched controls. An association between PPI use and increased cerebrovascular risks was identified, and the adjusted odds ratios for PPI use were 1.77 (95% CI 1.45-2.18, P<0.001) within 30 days, 1.65 (95% CI 1.31-2.08, P<0.001) between 31 and 90 days, and 1.28 (95% CI 1.03-1.59, P=0.025) between 91 and 180 days before the onset of first-time ischemic stroke.

CONCLUSIONS

PPI use is associated with an increased risk of first-time ischemic stroke in the general population, and the risk is independent of antiplatelet agents. However, caution should be exercised when considering its clinical relevance as the magnitude of association was modest and a cause-and-effect relationship remained to be established.

A Review of the Novel Application and Potential Adverse Effects of Proton Pump Inhibitors

Proton pump inhibitors (PPIs) are known as a class of pharmaceutical agents that target H⁺/K⁺-ATPase, which is located in gastric parietal cells. PPIs are widely used in the treatment of gastric acid-related diseases including peptic ulcer disease, erosive esophagitis and gastroesophageal reflux disease, and so on. These drugs present an excellent safety profile and have become one of the most commonly prescribed drugs in primary and specialty care. Except for gastric acid-related diseases, PPIs can also be used in the treatment of Helicobacter pylori infection, viral infections, respiratory system diseases, cancer and so on. Although PPIs are mainly used short term in patients with peptic ulcer disease, nowadays these drugs are increasingly used long term, and frequently for a lifetime, for instance in patients with typical or atypical symptoms of gastroesophageal reflux disease and in NSAID or aspirin users at risk of gastrotoxicity and related complications including hemorrhage, perforation and gastric outlet obstruction. Long-term use of PPIs may lead to potential adverse effects, such as osteoporotic fracture, renal damage, infection (pneumonia and clostridium difficile infection), rhabdomyolysis, nutritional deficiencies (vitamin B12, magnesium and iron), anemia and thrombocytopenia. In this article, we will review some novel uses of PPIs in other fields and summarize the underlying adverse reactions.

Concomitant Use of Proton-Pump Inhibitors and Clopidogrel Increases the Risk of Adverse Outcomes in Patients With Ischemic Stroke Carrying Reduced-Function CYP2C19*2

OBJECTIVE

Conflicting data exist as to whether proton-pump inhibitors (PPIs) diminish the efficacy of clopidogrel. The aim of this study was to investigate the association between cytochrome P450 ( CYP) genetic variants and clinical adverse outcomes of concomitant use of PPIs and clopidogrel by patients.

METHODS

We consecutively enrolled 523 patients with ischemic stroke receiving clopidogrel. Platelet aggregation was measured before and after 7 to 10 days of clopidogrel treatment. Single-nucleotide polymorphisms of CYP3A4, CYP3A5, CYP2C19*2, and CYP2C19*3 were examined using mass spectrometry. The primary outcome was a composite of recurrent ischemic stroke (RIS), myocardial infarction (MI), and vascular death that occurred during the 1-year follow-up period. The safety outcome was hemorrhagic episodes that occurred during the 1-year follow-up period.

RESULTS

This study comprised a total of 523 patients with IS, 96.3% (155/161) patients treated with PPIs and 95.9% (347/362) in patients treated without PPIs completed 1-year follow-up. The primary outcome was observed in 69 (13.7%) patients (56 RIS, 7 MI, and 6 died). There was no significant difference in the frequencies of primary outcome and safety outcome between patients treated with or without PPIs. The frequency of primary outcome was significantly higher in patients carrying CYP2C19*2 AG/AA genotype receiving PPIs compared with the same genotype in those not receiving PPIs. The PPIs used in patients carrying CYP2C19*2 AG/AA was independently associated with the primary outcome after adjusting for other risk factors.

CONCLUSIONS

The concomitant use of PPIs and clopidogrel may be associated with an increased risk of RIS, MI, or vascular death in patients with IS carrying reduced-function CYP2C19*2.

Combination Use of Clopidogrel and Proton Pump Inhibitors Increases Major Adverse Cardiovascular Events in Patients With Coronary Artery Disease: A Meta-Analysis

BACKGROUND

Published data indicated that combination use of clopidogrel and proton pump inhibitors (PPIs) may increase the incidence of major adverse cardiovascular events (MACEs). This has been a highly controversial topic for years.

DESIGN

The present study was performed to evaluate whether combination therapy of clopidogrel and PPIs is associated with increased risk of MACEs than with clopidogrel alone in patients with coronary artery disease.

METHODS

A systematic search of MEDLINE, EMBASE, and the Cochrane Library was conducted for studies recording the occurrence of MACEs in patients with exposure to concomitant use of clopidogrel and PPIs up to February 2015. Odds ratios (ORs) were combined using a random-effects model.

RESULTS

Patients receiving combination therapy with PPIs and clopidogrel were at significantly increased risk of MACEs (OR: 1.42; 95% confidence interval [CI]: 1.30-1.55). Adding a PPI to clopidogrel treatment was associated with a higher rate of MACE occurrence in rapid metabolizers (RMs, *1/*1) of CYP2C19 (OR: 1.42; 95% CI: 1.12-1.81), but there was no obviously increased rate (OR: 1.43; 95% CI: 0.89-2.28) in decreased metabolizers (with 1 or 2 loss-of-function allele). The increased risk of MACEs was similar in 4 classes of PPIs (omeprazole, lansoprazole, esomeprazole, and pantoprazole), but rabeprazole (OR: 1.03; 95% CI: 0.55-1.95) wasn't.

CONCLUSION

The combination use of clopidogrel and certain types of PPIs (omeprazole, lansoprazole, esomeprazole, pantoprazole) increases the risk of MACE in patients with coronary artery disease. Only in the RMs of CYP2C19, PPIs were associated with significantly increased MACE in patients coadministered with clopidogrel.

Changes in Prescription and Over-the-Counter Medication and Dietary Supplement Use Among Older Adults in the United States, 2005 vs 2011

IMPORTANCE

Prescription and over-the-counter medicines and dietary supplements are commonly used, alone and together, among older adults. However, the effect of recent regulatory and market forces on these patterns is not known.

OBJECTIVES

To characterize changes in the prevalence of medication use, including concurrent use of prescription and over-the-counter medications and dietary supplements, and to quantify the frequency and types of potential major drug-drug interactions.

DESIGN, SETTING, AND PARTICIPANTS

Descriptive analyses of a longitudinal, nationally representative sample of community-dwelling older adults 62 to 85 years old. In-home interviews with direct medication inspection were conducted in 2005-2006 and again in 2010-2011. The dates of the analysis were March to November 2015. We defined medication use as the use of at least 1 prescription or over-the-counter medication or dietary supplement at least daily or weekly and defined concurrent use as the regular use of at least 2 medications. We used Micromedex to identify potential major drug-drug interactions.

MAIN OUTCOMES AND MEASURES

Population estimates of the prevalence of medication use (in aggregate and by therapeutic class), concurrent use, and major drug-drug interactions.

RESULTS

The study cohort comprised 2351 participants in 2005-2006 and 2206 in 2010-2011. Their mean age was 70.9 years in 2005-2006 and 71.4 years in 2010-2011. Fifty-three percent of participants were female in 2005-2006, and 51.6% were female in 2010-2011. The use of at least 1 prescription medication slightly increased from 84.1% in 2005-2006 to 87.7% in 2010-2011 (P = .003). Concurrent use of at least 5 prescription medications increased from 30.6% to 35.8% (P = .02). While the use of over-the-counter medications declined from 44.4% to 37.9%, the use of dietary supplements increased from 51.8% to 63.7% (P < .001 for both). There were clinically significant increases in the use of statins (33.8% to 46.2%), antiplatelets (32.8% to 43.0%), and omega-3 fish oils (4.7% to 18.6%) (P < .05 for all). In 2010-2011, approximately 15.1% of older adults were at risk for a potential major drug-drug interaction compared with an estimated 8.4% in 2005-2006 (P < .001). Most of these interacting regimens involved medications and dietary supplements increasingly used in 2010-2011.

CONCLUSIONS AND RELEVANCE

In this study, the use of prescription medications and dietary supplements, and concurrent use of interacting medications, has increased since 2005, with 15% of older adults potentially at risk for a major drug-drug interaction. Improving safety with the use of multiple medications has the potential to reduce preventable adverse drug events associated with medications commonly used among older adults.

Pharmacoepidemiologic Methods for Studying the Health Effects of Drug-Drug Interactions

A drug-drug interaction (DDI) occurs when one or more drugs affect the pharmacokinetics (the body's effect on the drug) and/or pharmacodynamics (the drug's effect on the body) of one or more other drugs. Pharmacoepidemiologic studies are the principal way of studying the health effects of potential DDIs. This article discusses aspects of pharmacoepidemiologic research designs that are particularly salient to the design and interpretation of pharmacoepidemiologic studies of DDIs.