Effect of ibuprofen on cardioprotective effect of aspirin

Interactions of Nonsteroidal Antiinflammatory Drugs and Aspirin and Risk of Cardiovascular Disease in Patients With Osteoarthritis

Nonsteroidal antiinf lammatory drugs (NSAIDs) remain the mainstay of the pharmacologic management for relieving osteoarthritis pain, and low-dose aspirin is often prescribed to osteoarthritis patients who are at high risk of cardiovascular disease (CVD). We conducted cohort studies using data from The Health Improvement Network (THIN) database (2000-2019) to assess whether the relationship of initiation of naproxen or ibuprofen vs. initiation of other NSAIDs (excluding both naproxen and ibuprofen), respectively, to the risk of CVD was modified by coprescription of low-dose aspirin among the participants with osteoarthritis. Among participants without coprescription of aspirin, the risk of CVD was lower in naproxen initiators (10.3/1000 person-years) than in other NSAIDs initiators (13.2/1000 person-years; hazard ratio = 0.71, 95% confidence interval: 0.60, 0.85). Among participants with coprescription of aspirin, however, the risk of CVD was higher among naproxen initiators (36.9/1000 person-years) than that among other NSAIDs initiators (34.8/1000 person-years; hazard ratio = 1.48, 95% confidence interval: 1.12, 1.84). The association was significantly modified by coprescription of aspirin (P < 0.001). Similar findings were observed in the association of initiation of ibuprofen vs. other NSAIDs with the risk of CVD, which was significantly modified by coprescription of aspirin (P < 0.001). These findings suggest that osteoarthritis patients and clinicians should be aware of the potential CVD risk of concurrently taking naproxen or ibuprofen and low-dose aspirin.

Provider-directed analgesia for dental pain

INTRODUCTION

Extraction of impacted molar teeth is a common procedure performed by oral surgeons and general dentists, with postoperative pain being a significant adverse event post-surgery. If mismanaged, pain can lead to complications that impact oral and systemic health. The current scourge of the opioid epidemic has ushered in a new era of provider-directed analgesic (PDA) therapy in dentistry.

AREAS COVERED

This article provides an in-depth review on the major pharmacological and therapeutic properties of established and alternative analgesics used to manage dental pain.

EXPERT OPINION

Substantial evidence-based literature shows combination of a non-steroidal anti-inflammatory drug (NSAID; e.g. ibuprofen) and acetaminophen provides superior pain relief than single-agent or combination opioid regimens. However, there are clinical scenarios (e.g. severe pain) when short-course opioid prescription is appropriate in select patients, in which a 2-3-day treatment duration is typically sufficient. Alternative agents (e.g. caffeine, gabapentin, phytotherapies), typically in combination with established agents, can mitigate postoperative dental pain. Some evidence suggests preemptive therapies (e.g. corticosteroids, NSAIDs) reduce amounts of postsurgical analgesic consumption and might lessen opioid prescription burden. In summary, this comprehensive review provides an opportune update on the evolving landscape of pharmacotherapy for acute postsurgical dental pain, informing best practices for PDA in the dental setting.

Strategies for Avoiding Typical Drug-Drug Interactions and Drug-Related Problems in Patients with Vascular Diseases

Background and objectives: Drug-drug interactions and drug-related problems in patients with vascular diseases are common. To date, very few studies have focused on these important problems. The aim of the present study is to investigate the most common drug-drug interactions and DRPs in patients with vascular diseases. Materials and Methods: The medications of 1322 patients were reviewed manually in the time period from 11/2017 to 11/2018; the medications of 96 patients were entered into a clinical decision support system. Potential drug problems were identified, and a read-through consensus was reached between a clinical pharmacist and a vascular surgeon during the clinical curve visits; possible modifications were implemented. The focus was on additional dose adjustment and drug antagonization on drug interactions. Interactions were classified as contraindicated/high-risk combination (drugs must not be combined), clinically serious (interaction can be potentially life-threatening or have serious, possibly irreversible consequences), or potentially clinically relevant and moderate (interaction can lead to therapeutically relevant consequences). Results: A total of 111 interactions were observed. Of these, 6 contraindicated/high-risk combinations, 81 clinically serious interactions, and 24 potentially clinically relevant and moderate interactions were identified. Furthermore, 114 interventions were recorded and categorized. Discontinued use of the drug (36.0%) and drug dose adjustment (35.1%) were the most common interventions. Mostly, antibiotic therapy was continued unnecessarily (10/96; 10.4%), and the adjustment of the dosage to kidney function was overlooked in 40/96; 41.7% of the cases. In the most common cases, a dose reduction was not considered necessary. Here, unadjusted doses of antibiotics were found in 9/96, 9.3% of the cases. Notes for medical professionals summarized information that did not require direct intervention but rather increased attention on the part of the ward doctor. It was usually necessary to monitor laboratory parameters (49/96, 51.0%) or the patients for side effects (17/96, 17.7%), which were expected with the combinations used. Conclusions: This study could help identify problematic drug groups and develop prevention strategies for drug-related problems in patients with vascular diseases. A multidisciplinary collaboration between the different professional groups (clinical pharmacists and surgeons) might optimize the medication process. Collaborative care could have a positive impact on therapeutic outcomes and make drug therapy safer for patients with vascular diseases.

Perioperative Management of Oral Antithrombotics in Dentistry and Oral Surgery: Part 2

Part 1 of "Perioperative Management of Oral Antithrombotics in Dentistry and Oral Surgery" covered the physiological process of hemostasis and the pharmacology of both traditional and novel oral antiplatelets and anticoagulants. Part 2 of this review discusses various factors that are considered when developing a perioperative management plan for patients on oral antithrombotic therapy in consultation with dental professionals and managing physicians. Additionally included are how thrombotic and thromboembolic risks are assessed as well as how patient- and procedure-specific bleeding risks are evaluated. Special attention is given to the bleeding risks associated with procedures encountered when providing sedation and general anesthesia within the office-based dental environment.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

Management of Osteoarthritis: Expert Opinion on NSAIDs

Osteoarthritis (OA) is a leading cause of disability among older adults worldwide. Treatment aims are to alleviate inflammatory pain and improve physical function through non-pharmacological and pharmacological interventions. Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended as first-line therapy. However, selection is challenged by patient age, comorbidities and polypharmacy, and by the drug's benefit/risk balance, all of which together influence the risk of cardiovascular (CV), gastrointestinal (GI) and renal adverse events (AEs). While the efficacy profile of the various NSAIDs is delineated, the differences in their safety profile are not straightforward. This narrative review provides practical indications by a multidisciplinary Italian expert panel for general practitioners and specialists managing OA patients with chronic inflammatory pain; the goal is to maximize therapy efficacy while reducing untoward effects caused by inappropriate NSAID use. The discussion on the best approach to NSAIDs spanned the following topics: (1) patient evaluation: investigate pain origin, duration and components together with possible risk factors for CV, GI and renal AEs; (2) non-pharmacological interventions: the physiatrist provides a person-centered, holistic approach accounting for all patient aspects; (3) pharmacological interventions: patient profile and drugs' pharmacological properties affect NSAID selection, which drugs to be used in combination or to be avoided, formulation and therapy duration; (4) the pharmacologist's, general practitioner's and pain therapist's points of view; (5) NSAID safety: the individual baseline risk and the drug's safety profile are major determinants of CV, GI and renal risk; consider possible drug-drug interactions; (6) periodical re-evaluation of treatment response and adherence, using scales to assess pain and function.

[Résistance à l'aspirine : l'ennemi de mon ami est mon ennemi]

Low dose aspirin is an efficient antiplatelet agent to decrease the risk of occlusive arterial events, however it is not infallible. Aspirin resistance describe its inability to block the formation of thromboxane A2 in platelets and/or to produce an inhibitory effect on platelet aggregation. Detection of aspirin resistance relies on the results of various platelet function tests or on blood and urinary thromboxane metabolites concentrations, but these methods show very low correlation and reproducibility. Moreover, light-transmission aggregometry using arachidonic acid, known as the reference functional assay, requires technical expertise. The incidence rate of aspirin resistance amoung populations suffering from cardiovascular diseases is about 25%, however there is a wide variability depending on the specificity of the used test and the clinical features of the considered population. Aspirin resistance is associated with the recurrence of arterial occlusive events: the odds ratio is about 4 all tests combined, therefore it could be considered as a risk marker. Evidence is lacking regarding the relevance of these tests to resort an intensification of the antithrombotic treatment, and experts recommend to reserve their use for high-risk situations. Nevertheless several studies have explored the effect of dose increases or intake frequency increases, and revealed encouraging results regarding pharmacodynamic endpoints. The reasons for aspirin resistance are numerous, often remain debate, and can accumulate to result in poor response to aspirin.

Interaction Between Low-Dose Aspirin and Nonsteroidal Anti-Inflammatory Drugs Can Compromise Aspirin's Efficacy in Preventing Venous Thrombosis Following Total Joint Arthroplasty

Total joint arthroplasty is a rapid recovery procedure with patients optimized quickly in preparation for discharge. Two significant postoperative goals are effective pain management and prevention of postoperative venous thromboembolism (VTE). Low-risk patients receive aspirin 81 mg twice daily for VTE prophylaxis; this dosing regimen has been reduced over the past few years from 325 mg to 162 mg to 81 mg twice daily. Unless contraindications exist, all patients receive multimodal pain management that includes the use of celecoxib or meloxicam. Upon reduction of the aspirin dose to 81 mg twice daily, we rapidly identified 2 patients who developed a pulmonary embolus when celecoxib or meloxicam was administered concurrently with aspirin. The interaction between nonsteroidal anti-inflammatory drugs (NSAIDs) and low-dose aspirin varies among the different NSAIDs. It is also highly dependent on numerous factors, including time of administration, dose of aspirin, and both pharmacodynamics and dose of the NSAID. Real-world outcomes of concomitant administration of NSAIDs with low-dose aspirin led to increased incidence of VTE, possibly due to competitive inhibition of aspirin at platelet receptor sites. This interaction was mitigated by altering the administration times of both agents.

Role of oxylipins generated from dietary PUFAs in the modulation of endothelial cell function

Oxylipins, which are circulating bioactive lipids generated from polyunsaturated fatty acids (PUFAs) by cyclooxygenase, lipooxygenase and cytochrome P450 enzymes, have diverse effects on endothelial cells. Although studies of the effects of oxylipins on endothelial cell function are accumulating, a review that provides a comprehensive compilation of current knowledge and recent advances in the context of vascular homeostasis is lacking. This is the first compilation of the various in vitro, ex vivo and in vivo reports to examine the effects and potential mechanisms of action of oxylipins on endothelial cells. The aggregate data indicate docosahexaenoic acid-derived oxylipins consistently show beneficial effects related to key endothelial cell functions, whereas oxylipins derived from other PUFAs exhibit both positive and negative effects. Furthermore, information is lacking for certain oxylipin classes, such as those derived from α-linolenic acid, which suggests additional studies are required to achieve a full understanding of how oxylipins affect endothelial cells.

Practice Advisory on the Appropriate Use of NSAIDs in Primary Care

Cyclo-oxygenase (COX)-2 selective and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) are important in managing acute and chronic pain secondary to inflammation. As a greater understanding of the risks of gastrointestinal (GI), cardiovascular (CV) and renal events with NSAIDs use has emerged, guidelines have evolved to reflect differences in risks among NSAIDs. Updated guidelines have yet to reflect new evidence from recent trials which showed similar CV event rates with celecoxib compared to naproxen and ibuprofen, and significantly better GI tolerability for celecoxib. This practice advisory paper aims to present consensus statements and associated guidance regarding appropriate NSAID use based on a review of current evidence by a multidisciplinary group of expert clinicians. This paper is especially intended to guide primary care practitioners within Asia in the appropriate use of NSAIDs in primary care. Following a literature review, group members used a modified Delphi consensus process to determine agreement with selected recommendations. Agreement with a statement by 75% of total voting members was defined a priori as consensus. For low GI risk patients, any nonselective NSAID plus proton pump inhibitor (PPI) or celecoxib alone is acceptable treatment when CV risk is low; for high CV risk patients, low-dose celecoxib or naproxen plus PPI is appropriate. For high GI risk patients, celecoxib plus PPI is acceptable for low CV risk patients; low-dose celecoxib plus PPI is appropriate for high CV risk patients, with the alternative to avoid NSAIDs and consider opioids instead. Appropriate NSAID prescription assumes that the patient has normal renal function at commencement, with ongoing monitoring recommended. In conclusion, appropriate NSAID use requires consideration of all risks.

Selection of analgesics for the management of acute and postoperative dental pain: a mini-review

Pain management is an important part of dental practice, and dentists frequently prescribe analgesics to improve clinical outcomes. Dentists should be aware of the pharmacological characteristics of the analgesics commonly used in dentistry and should choose appropriate analgesics to treat and prevent pain associated with inflammation or surgery. In this article, we review the potential benefits and risks of the analgesics frequently used in dental practice and provide a stepwise approach for pain management.

Cardiovascular risk of nonsteroidal anti-inflammatory drugs in dialysis patients: a nationwide population-based study

Background

Given the cardiovascular risk of nonsteroidal anti-inflammatory drugs (NSAIDs), it is essential to identify the relationship between NSAIDs and cardiovascular outcomes in dialysis patients who have elevated cardiovascular risk.

Methods

A case-crossover study was conducted to assess the association of NSAIDs with major adverse cardiac and cerebrovascular events (MACCEs) and mortality using the Korean Health Insurance dataset. The case period was defined as 1–30 days prior to the event date and the control periods were defined as 61–90 days and 91–120 days prior to the event date.

Results

There were 3433 and 8524 incident dialysis patients who experienced MACCEs and mortality, respectively, after exposure to NSAIDs within 120 days before each event. NSAIDs significantly increased the risk of MACCEs {adjusted odds ratio [aOR] 1.37 [95% confidence interval (CI) 1.26–1.50]} and mortality [aOR 1.29 (95% CI 1.22–1.36)]. Nonselective NSAIDs, but not selective cyclooxygenase-2 inhibitors, significantly increased the risk of MACCEs and mortality. However, the MACCE and mortality risk did not increase in a dose-dependent manner in the analysis according to the cumulative defined daily dosage of NSAIDs. The incidence of MACCEs in the case period tended to be more common in patients who had recent exposure to NSAIDs than in patients who did not have recent exposure to NSAIDs.

Conclusions

Clinicians should be particularly cautious when prescribing NSAIDs to dialysis patients considering the associations of NSAIDs with cardiovascular outcomes and mortality, which might occur independent of the dose and duration of exposure.

Lessons Learned: Using the Caprini Risk Assessment Model to Provide Safe and Efficacious Thromboprophylaxis Following Hip and Knee Arthroplasty

Two of the more common potential complications after arthroplasty are venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolus (PE), and excess bleeding. Appropriate chemoprophylaxis choices are essential to prevent some of these adverse events and from exacerbating others. Risk stratification to prescribe safe and effective medications in the prevention of postoperative VTE has shown benefit in this regard. The Department of Orthopaedic Surgery at Syosset Hospital/Northwell Health, which performs over 1200 arthroplasties annually, has validated and is using the 2013 version of the Caprini Risk Assessment Model (RAM) to stratify each patient for risk of postoperative VTE. This tool results in a culling of information, past and present, personal and familial, that provides a truly thorough evaluation of the patient's risk for postoperative VTE. The Caprini score then guides the medication choices for thromboprophylaxis. The Caprini score is only valuable if the data is properly collected, and we have learned numerous lessons after applying it for 18 months. Risk stratification requires practice and experience to achieve expertise in perioperative patient evaluation. Having access to pertinent patient information, while gaining proficiency in completing the Caprini RAM, is vital to its efficacy. Ongoing, real time analyses of patient outcomes, with subsequent change in process, is key to improving patient care.

Not all (N)SAID and done: Effects of nonsteroidal anti-inflammatory drugs and paracetamol intake on platelets

Platelets are key mediators of hemostasis and thrombosis and can be inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs). As a result, platelet donors are temporarily deferred from donating if they have recently taken NSAIDs such as aspirin or ibuprofen. Despite these measures, a proportion of platelet donations show exposure to these drugs; however, little is known about the effect of NSAIDs and their metabolites on platelet quality in vivo and during storage. In this review, the effect of NSAIDs on platelet function is summarized, with a focus on the widely consumed over-the-counter (OTC) medications aspirin, ibuprofen, and the non-NSAID paracetamol. Aspirin and ibuprofen have well-defined antiplatelet effects. In comparison, studies regarding the effect of paracetamol on platelets report variable findings. The timing and order of NSAID intake is important, as concurrent NSAID use can inhibit or potentiate platelet activation depending on the drug taken. NSAID deferral periods and maximum platelet shelf-life is set by each country and are revised regularly. Reduced donor deferral periods and longer platelet storage times may affect the quality of platelet products, and it is therefore important to identify the possible impact of NSAID intake on platelet quality before and after storage.

No beneficial effects of aspirin on secondary cardiovascular prevention in patients with type 2 diabetes using non-steroidal anti-inflammatory drugs

There is little evidence on whether non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin interact in secondary cardiovascular prevention in type 2 diabetic patients. This is an observational study using data from the Action to Control Cardiovascular Risk in Diabetes and Follow-on studies. Hazard ratios (HRs) for mortality with 95% confidence intervals (95% CIs) were calculated using Cox proportional hazard models to compare time to death in patients using and not using aspirin who were simultaneously using or not using NSAIDs. A total of 3600 type 2 diabetic patients with cardiovascular disease were included. During a mean follow-up period of 8.8 years, 948 patients died. After adjustments, the risk of all-cause mortality in patients not using NSAIDs was significantly lower in those using aspirin than in those not using aspirin (HR, 0.81; 95% CI, 0.70-0.93; P = 0.004). The risk in patients using NSAIDs did not differ significantly between the two groups. There was a significant interaction between aspirin use and NSAIDs use. In type 2 diabetic patients with cardiovascular disease, aspirin use was not beneficial for those using NSAIDs.

Cardiorenal Safety of OTC Analgesics

Over-the-counter analgesics are used globally for the relief of acute pain. Although effective, these agents can be associated with adverse effects that may limit their use in some people. In the early 2000s, observations from clinical trials of prescription-strength and supratherapeutic doses of nonselective and cyclooxygenase-2-selective nonsteroidal anti-inflammatory drugs (NSAIDs) raised safety concerns regarding the risk of cardiovascular adverse effects with the use of these medications. Subsequently, the US Food and Drug Administration mandated additional study of the cardiovascular safety of NSAIDs for a more comprehensive understanding of their risk. As these data were being collected, and based on a comprehensive review of prescription data and the recommendations of the US Food and Drug Administration Advisory Committee, the warning labels of over-the-counter NSAIDs were updated to emphasize the potential cardiovascular risks of these agents. The recently reported “Prospective Randomized Evaluation of Celecoxib Integrated Safety versus Ibuprofen or Naproxen” (PRECISION) trial, in which participants with osteoarthritis or rheumatoid arthritis and underlying cardiovascular risk factors were treated with prescription-strength celecoxib, ibuprofen, or naproxen, revealed similar rates of cardiovascular events (death from cardiovascular causes including hemorrhagic death, nonfatal myocardial infarction, or nonfatal stroke) among the 3 treatment groups. Although informative, the cardiovascular safety findings derived from PRECISION cannot be extrapolated to the safety of the over-the-counter pain relievers ibuprofen and naproxen, given that the doses used were higher (mean [standard deviation]: ibuprofen, 2045 [246] mg; naproxen, 852 [103] mg) and the durations of use longer (∼20 months) than recommended with over-the-counter use of NSAIDs, which for ibuprofen is up to 10 days. This review discusses the cardiorenal safety of the most commonly used over-the-counter analgesics, ibuprofen, naproxen, and acetaminophen. Available data suggest that there is little cardiovascular risk when over-the-counter formulations of these agents are used as directed in their labels.

Pharmacoepidemiology of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are reversible inhibitors of cyclo-oxygenase (COX), mainly used for the symptomatic relief of pain, whether traumatic, infectious, episodic or rheumatologic. Use for the long-term relief of inflammation is waning with the emergence of specific biotherapies. Their effects are related to potency, dosage, and pharmacokinetic or galenic considerations. Adverse reactions are mostly related to COX inhibition, and to the relative COX1 and COX2 inhibition. Over the years have resulted in the withdrawal of some NSAIDs. The most common adverse reactions are: gastrointestinal (COX1) which have declined over time with the emergence of more COX1 sparing drugs and gastroprotection; renal, with an impact on renal function and sodium extraction that is associated with hypertension, heart failure exacerbation, and stress-related renal failure; allergic skin reactions; increased transaminases and acute liver injury which may be idiosyncratic or immunoallergic; increased risk of acute coronary syndromes, initially associated with high-dose long-term use of COX2 specific inhibitors in controlled clinical trials, though more recently there have been indications from poorly controlled observational studies that they could occur with most NSAIDs. Event rates in patients with no overt coronary heart disease are vanishingly low, and the real magnitude of the issue in the treatment of common pain is still unknown. Considering their purely symptomatic effects, they should be used at the lowest possible dose for the shortest possible time, based on the symptomatic relief of pain or fever.

Aspirin in primary prevention for patients with diabetes: Still a matter of debate

BACKGROUND

Patients with diabetes are at high cardiovascular (CV) risk due to an exaggerated platelet activation and aggregation. In the first 2000s low-dose aspirin was first recommended for primary prevention, but then re-discussed.

METHODS

This short narrative review, based on the material searched for and obtained via PubMed up to February 2018, aims at clarifying this controversial topic.

RESULTS

The JPAD2 study has been designed to evaluate the occurrence of any CV event in a cohort of patients with diabetes and concluded that low-dose aspirin did not influence the risk for CV events while increasing the risk for gastrointestinal (GI) bleeding. Reasons for this result can be found in the role of diabetic platelets, which are known to be hyperreactive, thus producing intensified adhesion, activation, and aggregation. In this setting, other associated metabolic conditions can concur to enhance platelet adhesion and activation. Aspirin resistance has been often considered a guilty actor, although many mechanisms have been mistaken for true aspirin resistance, such as patient poor compliance, inadequate dosing, drug interactions, and high-platelet turnover. However, the mere presence of diabetes is not likely to give a net benefit for CV protection with respect to GI bleeding.

CONCLUSION

It appears advisable to follow current guidelines addressing first of all classical risk factors and evaluate aspirin therapy in primary prevention only for patients with type 1 or 2 diabetes at increased CV risk and no risk for GI bleeding. Anyway, additional clinical trials are needed to address the current topic.

Role of Dipyrone in the High On-Treatment Platelet Reactivity amongst Acetylsalicylic Acid-Treated Patients Undergoing Peripheral Artery Revascularisation

OBJECTIVE

To evaluate the effects of dipyrone on sensitivity to aspirin (acetylsalicylic acid [ASA]) in patients who underwent peripheral artery vascular reconstruction.

SUBJECTS AND METHODS

Impedance aggregometry and light transmission aggregometry were used to determine the effects of dipyrone on ASA treatment in 21 patients. Blood samples were drawn in a 7-day period after the surgery. The cut-off value for high on-treatment platelet reactivity (HTPR) was set at < 65% of aggregation inhibition for impedance aggregometry. For light transmission aggregometry the cut-off value for arachidonic acid-induced aggregation was set at > 20% of aggregating platelets, and the cut-off value for epinephrine-induced aggregation was > 44% of aggregating platelets. The cut-off value for each method was derived from a large number of patients treated with a daily dose of 100 mg of ASA.

RESULTS

We found HTPR in 14 (67%) of the 21 patients. None had primary resistance to ASA, i.e., after the addition of ASA in vitro all samples showed antiplatelet efficacy. Regression analysis showed a possible correlation between lower efficacy of ASA treatment and higher daily doses of dipyrone (p = 0.005 for impedance aggregometry, p = 0.04 for light transmission aggregometry), higher platelet count (p = 0.005 for impedance aggregometry), and shorter time from surgery (p = 0.03 for impedance aggregometry).

CONCLUSION

HTPR occurs in 67% of ASA-treated patients after lower limb vascular surgery. The occurrence of HTPR correlates with the daily dose of dipyrone. Therefore, dipyrone should not be used as a postoperative analgesic in ASA-treated patients after peripheral artery revascularisation due to its influence on the effectiveness of ASA.

Drug-drug interaction discovery and demystification using Semantic Web technologies

Objective

To develop a novel pharmacovigilance inferential framework to infer mechanistic explanations for asserted drug-drug interactions (DDIs) and deduce potential DDIs.

Materials and Methods

A mechanism-based DDI knowledge base was constructed by integrating knowledge from several existing sources at the pharmacokinetic, pharmacodynamic, pharmacogenetic, and multipathway interaction levels. A query-based framework was then created to utilize this integrated knowledge base in conjunction with 9 inference rules to infer mechanistic explanations for asserted DDIs and deduce potential DDIs.

Results

The drug-drug interactions discovery and demystification (D3) system achieved an overall 85% recall rate in terms of inferring mechanistic explanations for the DDIs integrated into its knowledge base, while demonstrating a 61% precision rate in terms of the inference or lack of inference of mechanistic explanations for a balanced, randomly selected collection of interacting and noninteracting drug pairs.

Discussion

The successful demonstration of the D3 system's ability to confirm interactions involving well-studied drugs enhances confidence in its ability to deduce interactions involving less-studied drugs. In its demonstration, the D3 system infers putative explanations for most of its integrated DDIs. Further enhancements to this work in the future might include ranking interaction mechanisms based on likelihood of applicability, determining the likelihood of deduced DDIs, and making the framework publicly available.

Conclusion

The D3 system provides an early-warning framework for augmenting knowledge of known DDIs and deducing unknown DDIs. It shows promise in suggesting interaction pathways of research and evaluation interest and aiding clinicians in evaluating and adjusting courses of drug therapy.

Dose-dependent effect of early antiplatelet therapy in acute ischaemic stroke

Antiplatelet agents are essential in treating patients with acute ischaemic stroke (AIS) to prevent recurrent ischaemic events. The aim of this study was to evaluate the effectiveness of early antiplatelet therapy with different aspirin (ASA) dosages in patients with AIS. This observational study included 454 patients with AIS in whom antiplatelet treatment was initiated. The antiplatelet effect was determined by whole blood aggregometry within 48 hours after antplatelet therapy was initiated. An impedance change exceeding 0 Ω after stimulation with arachidonic acid was defined as ASA low response (ALR) and ≥5 Ω in ADP-stimulated specimen as clopidogrel LR. Of the study group 53.5% patients were treated with 200 mg ASA orally, 27.5% with 500 mg ASA intravenously, 8.6% with 100 mg ASA orally, and 7.7% with 75 mg clopidogrel. A dose-dependent antiplatelet effect of ASA treatment was found: 18.4% of patients with 500 mg ASA intravenously were ALR, in contrast to 32.5% on 200 mg and 35.9% on 100 mg ASA orally. Clopidogrel treatment without a loading dose resulted in a high proportion of LR (45.7%). Using the propensity score method revealed a three times higher risk for ALR for patients treated with ASA 200 mg [odds ratio 2.99 (1.55–5.79)] compared to treatment with ASA 500 mg. In conclusion, initiating antiplatelet therapy in patients with AIS resulted in a dose-dependent insufficient platelet inhibitory effect. Our findings suggest using a loading dose of 500 mg ASA intravenously as this seems to be favourable when a sufficient early platelet inhibitory effect is wanted.

ClinicalTrials.gov Identifier: NCT01273935

Effect of Aspirin and ibuprofen either alone or in combination on gastric mucosa and bleeding time and on serum prostaglandin E2 and thromboxane A2 levels in the anaesthetized rats in vivo

There is much evidence that a combination of ibuprofen (IBU) and Aspirin (ASA) can antagonize the irreversible inhibition of platelet function. This study was designed to investigate the degree of gastric damage, bleeding time (BT) and fluctuations in the serum levels of prostaglandin E₂ (PGE₂) and thromboxane A₂ (TXA₂) after oral administration of ASA (200 mg/kg) and IBU (50 mg/kg) either alone or in combination in rats in vivo. The stomach was assessed for any damage either after 6 h, 18 h or 6 days and carboxymethylcellulose (1% CMC) served as a vehicle and control. ELISA was used to measure TXA₂ and PGE₂ in serum. Bleeding time was assessed using tail blood. The results show that ASA and IBU either alone or in combination can cause gastric ulceration in 25-100% of the rats at 6 and 18 h. In contrast, gastric ulceration was seen in 50% of rats with a combination of ASA given before IBU only after 6 days of oral administration. BT was unaffected either by ASA or IBU when administered alone except after 18 h for IBU. In contrast, BT was significantly reduced when IBU was administered before ASA after 18 h and 6 days (P < 0.001). Serum PGE₂ levels decreased significantly after ASA administered either alone or in combination with IBU for 6 h, 18 h and 6 days (P < 0.05). Serum TXA₂ levels were significantly reduced after 6 h, 18 h and 6 days following ASA and IBU administration except for IBU alone which caused a significant increase in serum TXA₂ 6 days after its administration (P < 0.01). It can be concluded that ASA and IBU administered either alone or in combination can cause gastric ulcers in the rat stomach after 6 h and 18 h, but less severe after 6 days. IBU either alone or in combination with ASA reduced BT only after 18 h and 6 days of administration. Together, the results show that gastric ulceration correlated well with the inhibition of serum PGE₂ and TXA₂ levels.

Metamizole and Platelet Inhibition by Aspirin Following On-Pump Coronary Artery Bypass Grafting

OBJECTIVE

The purpose of the study was to evaluate the impact of intravenous metamizole on platelet inhibition by aspirin in patients with coronary artery disease early after on-pump coronary artery bypass grafting (CABG).

DESIGN

Prospective, single-blind, randomized trial.

SETTING

Tertiary referal hospital.

PARTICIPANTS

The study comprised 43 patients with multivessel coronary artery disease undergoing CABG.

INTERVENTIONS

Patients were randomized to postoperative intravenous metamizole ± opioids (study group; n = 23) or opioids alone (control group; n = 20). Aspirin was withheld at least 7 days before the surgery and reinitiated (300 mg) immediately after the procedure prior to metamizole use, and continued daily thereafter (150 mg). Platelet function was evaluated using multielectrode impedance aggregometry (acid-induced platelet activation [ASPI] and collagen-induced platelet activation [COL] test), P-selectin expression and urinary 11-dehydro-thromboxane B₂ (11-DTXB₂) level at baseline, postoperative day (POD) 0, POD 1, POD 2, and POD 6. Residual platelet reactivity (RPR) was defined as ASPI test >400 AU*min.

MEASUREMENTS AND MAIN RESULTS

In all study participants, postoperative ASPI test value moderately decreased (1058.2 v 966.6 AU*min, p = 0.047), urinary 11-DTXB₂ level increased (923.4 v 4367.3 pg/mg, p < 0.001), and P-selectin expression and COL test value remained stable postprocedure. The decreases of ASPI (p = 0.146) and COL test (p = 0.642), and P-selectin expression (p = 0.318) did not differ between both groups. Patients in the control group had higher postoperative increase of urinary 11-DTXB₂ level (p = 0.001). The prevalence of RPR was high and comparable between study and control groups (day 1, 95.6% v 100%, p = 0.535; day 6, 100% v 90%, p = 0.21). Multivariate analysis revealed that metamizole use did not predict the fluctuations of ASPI and COL test values and P-selectin expression, yet it independently predicted postoperative change of 11-DTXB₂ level (b = -0.518, p = 0.001).

CONCLUSIONS

Intravenous metamizole preceded by a loading dose of aspirin did not modify platelet response to aspirin in the postoperative period after CABG.

Clinical Pharmacology and Cardiovascular Safety of Naproxen

The voluntary withdrawal of Vioxx (rofecoxib) from the market in 2004, as well as the 2005 and 2014 US FDA Advisory Committee meetings about non-steroidal anti-inflammatory drugs (NSAIDs) and cardiovascular risk, have raised questions surrounding the use of NSAIDs in at-risk populations. This paper discusses the cardiovascular safety profile of naproxen in the context of the NSAID class. The balance of evidence suggests that cardiovascular risk correlates with cyclooxygenase (COX)-2 selectivity, and the low COX-2 selectivity of naproxen results in a lower cardiovascular risk than that of other NSAIDs. The over-the-counter (OTC) use of naproxen is expected to pose minimal cardiovascular risk; however, the benefit-risk ratio and appropriate use should be considered at an individual patient level, particularly to assess underlying conditions that may increase the risk of events. Likewise, regulatory authorities should revisit label information periodically to ensure labeling reflects the current understanding of benefits and risks.

Influence of nonsteroidal anti-inflammatory drugs on aspirin's antiplatelet effects and suggestion of the most suitable time for administration of both agents without resulting in interaction

Background

Low-dose aspirin irreversibly inhibits platelet cyclooxygenase-1 (COX-1) and suppresses platelet aggregation. It is effective for secondary prevention of cardiovascular events. Because nonsteroidal anti-inflammatory drugs (NSAIDs) reversibly bind with COX-1, the antiplatelet effects of aspirin may be suppressed when NSAIDs are co-administered. This interaction could be avoided by avoiding simultaneous administration; however, the minimum interval that should separate the administration of aspirin and loxoprofen is not well known. In this study, we investigated how to avoid the influence of NSAIDs on the antiplatelet effects of aspirin. An in vitro experiment was performed to investigate the influence of ibuprofen and loxoprofen at various concentrations on aspirin’s antiplatelet action.

Methods

Platelet aggregation and thromboxane B₂ (TXB₂) levels were measured after addition of aspirin only and NSAIDs plus aspirin to platelet-rich plasma. NSAIDs were used at their maximum plasma concentrations, the assumed concentration after 6 h (for loxoprofen only), and the assumed concentration after 12 h of taking one clinical dose. Platelet aggregation threshold index (PATI), defined as the putative stimulus concentration giving 50% aggregation, was calculated as an index of aggregation activity.

Results

PATI decreased in ibuprofen plus aspirin group compared to that in the aspirin only group, regardless of ibuprofen concentration. Furthermore, PATI significantly decreased when aspirin was added after loxoprofen-trans-OH addition at the maximum concentration (4.1 ± 0.1 μg/mL), compared to that in aspirin only group (5.9 ± 0.1 μg/mL). PATI showed no significant difference after addition of loxoprofen at the assumed concentration after 6 h (aspirin only group, 5.0 ± 0.5 μg/mL; loxoprofen-trans-OH plus aspirin group, 4.9 ± 0.4 μg/mL).In addition, TXB₂ concentration tended to decrease with increasing PATI.

Conclusions

It is desirable to avoid ibuprofen co-administration with the usual once-daily low-dose aspirin therapy; however, a 6-h interval between loxoprofen and aspirin could avoid this potential interaction when loxoprofen is taken before aspirin.

Impact of Nonsteroidal Antiinflammatory Drugs on the Cardioprotective Effects of Aspirin

OBJECTIVE:

To examine the evidence of a pharmacodynamic interaction between aspirin and nonsteroidal antiinflammatory drugs (NSAIDs); specifically, to determine whether a deleterious relationship exists with respect to the cardioprotective effects of aspirin.

DATA SOURCES:

Primary articles were identified by a MEDLINE search (1966—May 2004). Search terms included aspirin, nonsteroidal antiinflammatory drug, drug interaction, mortality, myocardial infarction, and stroke.

STUDY SELECTION AND DATA EXTRACTION:

All prospective and retrospective studies conducted in human subjects and investigating the potential interaction between aspirin and NSAIDs were included.

DATA SYNTHESIS:

Several controlled pharmacodynamic studies indicate that the sustained inhibition of cyclooxygenase activity by aspirin is blunted in the presence of some NSAIDs. While these data are fairly consistent, they are limited in that they rely on surrogate markers and not clinical outcomes. Observational studies have shown conflicting results regarding the effect of combination NSAID and aspirin therapy on mortality risk and incidence of myocardial infarction.

CONCLUSIONS:

Pharmacodynamic data indicating an interaction between aspirin and NSAIDs have not translated to a consistent clinical effect in observational studies. In the absence of a randomized, controlled, clinical outcomes study, there is insufficient evidence to dictate a change in therapy.

[DGRh recommendations for the implementation of current security aspects in the NSAID treatment of musculoskeletal pain]

NSAIDs exert their anti-inflammatory and analgesic effects by inhibition of COX‑2, a key enzyme for proinflammatory prostanoid synthesis. Therapy with NSAIDs is limited by their typical gastrointestinal, cardiovascular and renal side effects, which are caused by inhibition of COX‑1 (gastrointestinal toxicity), COX‑2 (cardiovascular side effects) or both COX-isoenzymes (renal side effects). Appropriate prevention strategies should be employed in patients at risk. If gastrointestinal risk factors are present, co-administration of a proton pump inhibitor or misoprostol is recommended; in patients with cardiovascular risk, coxibs, diclofenac and high-dose ibuprofen should be avoided. Furthermore, drug interactions and contraindications should be considered. In patients with renal impairment (GFR < 30 ml/min) all NSAIDs must be avoided. Ulcer anamnesis is a contraindication for traditional NSAIDs. Preexisting cardio- or cerebrovascular diseases are contraindications for coxibs. Treatment decisions should be individually based with a continuous monitoring of the risk - benefit ratio and exploitation of non-pharmacological treatment options.

[Analgesics in geriatric patients. Adverse side effects and interactions]

Pain is a widespread symptom in clinical practice. Older adults and chronically ill patients are particularly affected. In multimorbid geriatric patients, pharmacological pain treatment is an extension of a previously existing multimedication. Besides the efficacy of pain treatment, drug side effects and drug-drug interactions have to be taken into account to minimize the health risk for these patients. Apart from the number of prescriptions, the age-related pharmacokinetic and pharmacodynamic changes significantly increase the risk among older adults. The use of non-steroidal anti-inflammatory drugs (NSAID) is widespread but NSAIDs have the highest risk of adverse drug reactions and drug interactions. In particular, the gastrointestinal, cardiovascular, renal and coagulation systems are affected. Apart from the known toxic effect on the liver (in high doses), paracetamol (acetaminophen) has similar risks although to a lesser degree. According to current data, metamizol is actually better than its reputation suggests. The risk of potential drug interactions seems to be low. Apart from the risk of sedation in combination with other drugs, tramadol and other opioids can induce the serotonin syndrome. Among older adults, especially in the case of polypharmacy, an individualized approach should be considered instead of sticking to the pain management recommended by the World Health Organization (WHO) in order to minimize drug-drug interactions and adverse drug reactions.

Risk of Bias in Systematic Reviews of Non-Randomized Studies of Adverse Cardiovascular Effects of Thiazolidinediones and Cyclooxygenase-2 Inhibitors: Application of a New Cochrane Risk of Bias Tool

BACKGROUND

Systematic reviews of the effects of healthcare interventions frequently include non-randomized studies. These are subject to confounding and a range of other biases that are seldom considered in detail when synthesizing and interpreting the results. Our aims were to assess the reliability and usability of a new Cochrane risk of bias (RoB) tool for non-randomized studies of interventions and to determine whether restricting analysis to studies with low or moderate RoB made a material difference to the results of the reviews.

METHODS AND FINDINGS

We selected two systematic reviews of population-based, controlled non-randomized studies of the relationship between the use of thiazolidinediones (TZDs) and cyclooxygenase-2 (COX-2) inhibitors and major cardiovascular events. Two epidemiologists applied the Cochrane RoB tool and made assessments across the seven specified domains of bias for each of 37 component studies. Inter-rater agreement was measured using the weighted Kappa statistic. We grouped studies according to overall RoB and performed statistical pooling for (a) all studies and (b) only studies with low or moderate RoB. Kappa scores across the seven bias domains ranged from 0.50 to 1.0. In the COX-2 inhibitor review, two studies had low overall RoB, 14 had moderate RoB, and five had serious RoB. In the TZD review, six studies had low RoB, four had moderate RoB, four had serious RoB, and two had critical RoB. The pooled odds ratios for myocardial infarction, heart failure, and death for rosiglitazone versus pioglitazone remained significantly elevated when analyses were confined to studies with low or moderate RoB. However, the estimate for myocardial infarction declined from 1.14 (95% CI 1.07-1.24) to 1.06 (95% CI 0.99-1.13) when analysis was confined to studies with low RoB. Estimates of pooled relative risks of cardiovascular events with COX-2 inhibitors compared with no nonsteroidal anti-inflammatory drug changed little when analyses were confined to studies with low or moderate RoB. The exception was a rise in the relative risk associated with ibuprofen from 1.07 (95% CI 0.97-1.18) to 1.14 (95% CI 1.03-1.26). The main limitation of our study was testing the instrument on a narrow range of pharmacoepidemiological studies; we cannot assume our findings extend to a broader range of interventions and settings.

CONCLUSIONS

The Cochrane RoB tool highlighted a wide range of risks of bias in studies included in two widely cited reviews and had the potential to change the conclusions of the reviews. Systematic reviews that incorporate non-randomized studies of medical interventions should include a detailed assessment of RoB for each included study.

Short-term use of nonsteroidal anti-inflammatory drugs and adverse effects: An updated systematic review

BACKGROUND

In this article, the authors examine the available scientific evidence regarding adverse effects of short-term use of nonsteroidal anti-inflammatory drugs (NSAIDs). Short-term use was defined as 10 days or fewer.

METHODS

The authors reviewed randomized controlled clinical trials and cohort and case-controlled clinical studies published between 2001 and June 2015 in which the investigators reported on the safety of nonselective cyclooxygenase inhibitors and of cyclooxygenase-2 selective inhibitor NSAIDs.

RESULTS

The systematic review process according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines allowed the authors to identify 40 studies that met the inclusion criteria.

CONCLUSIONS

On the basis of the available scientific evidence, NSAIDs may be considered relatively safe drugs when prescribed at the most effective dose and for the shortest duration of time, which was defined to be 10 days or fewer.

PRACTICAL IMPLICATIONS

Although the US Food and Drug Administration recommends the use of NSAIDs beyond 10 days to be accompanied by a consultation with a health care provider, the use of NSAIDs may be considered relatively safe when prescribed at the most effective dose and for the shortest duration of time, which was defined as 10 days or fewer. Exceptions would be for patients at risk of developing NSAID-exacerbated respiratory disease, patients with prior myocardial infarction who are receiving antithrombotic therapy, patients with asthma, and patients with a history of renal disease.

Pharmaceutical Residues in Sewage Treatment Works and their Fate in the Receiving Environment

Pharmaceuticals are increasingly used in large amounts in human (and veterinary) medicine around the world. They reach the aquatic environment mainly through sewage treatment systems and can reach μg l−1 levels. The continual input of pharmaceuticals to the aquatic environment, via sewage, can also impart a persistent quality to compounds that otherwise possess no inherent environmental stability. While the literature contains increasing numbers of studies detailing fate, effects and behaviour in the environment, the subject is still not fully understood for all the different therapeutic classes. The toxicological significance for non-target (especially aquatic) organisms is poorly understood. The use/release of antibiotics and natural/synthetic steroids to the environment has generated most of the concern to date, but a plethora of other drugs are increasingly attracting attention, as their biological activity alone may support ecotoxicity assessments of those compounds with high production volumes (or toxicity), especially in view of the increasing importance of freshwater resources. Pharmaceuticals display a variety of removal efficiencies during wastewater treatment and their fate and behaviour are not determined by their physicochemical properties alone. Despite the fact that many drugs have high sorption potentials, partitioning to the solid phase was determined to be an unlikely removal pathway for the majority of compounds. The partitioning behaviour of these compounds both in sewage treatment and the aquatic environment is likely to be dictated by a number of physicochemical parameters. Findings also indicate that the costs of using tertiary treatment options (mainly based on drinking water treatment) to remove drugs from wastewater effluent are likely to be prohibitively expensive, and potentially undesirable, due sustainability implications. While adjusting existing treatment parameters may increase the removal efficiencies of pharmaceuticals, any changes to sewage treatment parameters would need to be offset against the economic and environmental costs. Likewise, any regulations on drug use must be balanced against health benefits. If receiving waters are used for potable supplies, the presence of these compounds may (although it is unlikely) represent a potential hazard to human health, especially in areas without advanced water treatment. The focus for future research should therefore be on proper and sufficient science for establishing the occurrence, exposure and effects of pharmaceuticals in the environment, so that sound decisions can be made regarding human and ecological health.

Adverse drug reactions and drug-drug interactions with over-the-counter NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen have a long history of safe and effective use as both prescription and over-the-counter (OTC) analgesics/antipyretics. The mechanism of action of all NSAIDs is through reversible inhibition of cyclooxygenase enzymes. Adverse drug reactions (ADRs) including gastrointestinal bleeding as well as cardiovascular and renal effects have been reported with NSAID use. In many cases, ADRs may occur because of drug-drug interactions (DDIs) between the NSAID and a concomitant medication. For example, DDIs have been reported when NSAIDs are coadministered with aspirin, alcohol, some antihypertensives, antidepressants, and other commonly used medications. Because of the pharmacologic nature of these interactions, there is a continuum of risk in that the potential for an ADR is dependent on total drug exposure. Therefore, consideration of dose and duration of NSAID use, as well as the type or class of comedication administered, is important when assessing potential risk for ADRs. Safety findings from clinical studies evaluating prescription-strength NSAIDs may not be directly applicable to OTC dosing. Health care providers can be instrumental in educating patients that using OTC NSAIDs at the lowest effective dose for the shortest required duration is vital to balancing efficacy and safety. This review discusses some of the most clinically relevant DDIs reported with NSAIDs based on major sites of ADRs and classes of medication, with a focus on OTC ibuprofen, for which the most data are available.

Use of low-dose aspirin as secondary prevention of atherosclerotic cardiovascular disease in US adults (from the National Health Interview Survey, 2012)

Current guidelines recommend that adults with atherosclerotic cardiovascular disease take low-dose aspirin or other antiplatelet medications as secondary prevention of recurrent cardiovascular events. Yet, no national level assessment of low-dose aspirin use for secondary prevention of cardiovascular disease has been reported in a community-based population. Using data from the 2012 National Health Interview Survey, we assessed low-dose aspirin use in those with atherosclerotic cardiovascular disease. We estimated the prevalence ratios of low-dose aspirin use, adjusting for sociodemographic status, health insurance, and cardiovascular risk factors. In those with atherosclerotic cardiovascular disease (n = 3,068), 76% had been instructed to take aspirin and 88% of those were following this advice. Of those not advised, 11% took aspirin on their own. Overall, 70% were taking aspirin (including those who followed their health care provider's advice and those who were not advised but took aspirin on their own). Logistic regression models showed that women, non-Hispanic blacks and Hispanics, those aged 40 to 64 years, with a high school education or with some college, or with fewer cardiovascular disease risk factors were less likely to take aspirin than men, non-Hispanic whites, those aged ≥65 years, with a college education or higher, or with all 4 selected cardiovascular disease risk factors, respectively. Additional analyses conducted in those with coronary heart disease only (n = 2,007) showed similar patterns. In conclusion, use of low-dose aspirin for secondary prevention was 70%, with high reported adherence to health care providers' advice to take low-dose aspirin (88%) and significant variability within subgroups.

Safe prescribing of non-steroidal anti-inflammatory drugs in patients with osteoarthritis--an expert consensus addressing benefits as well as gastrointestinal and cardiovascular risks

BACKGROUND

There are several guidelines addressing the issues around the use of NSAIDs. However, none has specifically addressed the upper versus lower gastrointestinal (GI) risk of COX-2 selective and non-selective compounds nor the interaction at both the GI and cardiovascular (CV) level of either class of drugs with low-dose aspirin. This Consensus paper aims to develop statements and guidance devoted to these specific issues through a review of current evidence by a multidisciplinary group of experts.

METHODS

A modified Delphi consensus process was adopted to determine the level of agreement with each statement and to determine the level of agreement with the strength of evidence to be assigned to the statement.

RESULTS

For patients with both low GI and CV risks, any non-selective NSAID (ns-NSAID) alone may be acceptable. For those with low GI and high CV risk, naproxen may be preferred because of its potential lower CV risk compared with other ns-NSAIDs or COX-2 selective inhibitors, but celecoxib at the lowest approved dose (200 mg once daily) may be acceptable. In patients with high GI risk, if CV risk is low, a COX-2 selective inhibitor alone or ns-NSAID with a proton pump inhibitor appears to offer similar protection from upper GI events. However, only celecoxib will reduce mucosal harm throughout the entire GI tract. When both GI and CV risks are high, the optimal strategy is to avoid NSAID therapy, if at all possible.

CONCLUSIONS

Time is now ripe for offering patients with osteoarthritis the safest and most cost-effective therapeutic option, thus preventing serious adverse events which could have important quality of life and resource use implications. Please see related article: http://dx.doi.org/10.1186/s12916-015-0291-x.

New insights into the use of currently available non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs), which act via inhibition of the cyclooxygenase (COX) isozymes, were discovered more than 100 years ago. They remain a key component of the pharmacological management of acute and chronic pain. The COX-1 and COX-2 isozymes have different biological functions; analgesic activity is primarily (although not exclusively) associated with inhibition of COX-2, while different side effects result from the inhibition of COX-1 and COX-2. All available NSAIDs, including acetaminophen and aspirin, are associated with potential side effects, particularly gastrointestinal and cardiovascular effects, related to their relative selectivity for COX-1 and COX-2. Since all NSAIDs exert their therapeutic activity through inhibition of the COX isozymes, strategies are needed to reduce the risks associated with NSAIDs while achieving sufficient pain relief. A better understanding of the inhibitory activity and COX-1/COX-2 selectivity of an NSAID at therapeutic doses, based on pharmacokinetic and pharmacodynamic properties (eg, inhibitory dose, absorption, plasma versus tissue distribution, and elimination), and the impact on drug tolerability and safety can guide the selection of appropriate NSAIDs for pain management. For example, many NSAIDs with moderate to high selectivity for COX-2 versus COX-1 can be administered at doses that maximize efficacy (~80% inhibition of COX-2) while minimizing COX-1 inhibition and associated side effects, such as gastrointestinal toxicity. Acidic NSAIDs with favorable tissue distribution and short plasma half-lives can additionally be dosed to provide near-constant analgesia while minimizing plasma concentrations to permit recovery of COX-mediated prostaglandin production in the vascular wall and other organs. Each patient’s clinical background, including gastrointestinal and cardiovascular risk factors, should be taken into account when selecting appropriate NSAIDs. New methods are emerging to assist clinicians in the selection of appropriate NSAIDs and their doses/schedules, such as biomarkers that may predict the response to NSAID treatment in individual patients.