BackgroundThe safety of ondansetron for nausea and vomiting in pregnancy (NVP) remains a subject of ongoing debate, driven by conflicting study results and a disagreement between the European Medicines Agency (EMA) and the European Network of Teratology Information Services (ENTIS) regarding its potential fetal risks.ObjectiveTo assess the safety of using ondansetron for NVP and its possible association with major birth defects and neonatal outcomes.MethodsA prospective cohort study was conducted based on structured telephone follow-ups of women with NVP who contacted the NVP Helpline at a teratology information service (TIS) at the Shamir Medical Center between April 2014 and April 2018. Exposure and clinical characteristics were recorded during the initial consultation, and pregnancy and neonatal outcomes were ascertained after the estimated date of delivery using a validated questionnaire. Women treated with ondansetron formed the exposed group; controls did not receive ondansetron but could use other NVP therapies. Subgroup analyses explored the dose and frequency of use.ResultsThe analysis included 260 women (137 exposed; 123 controls). Baseline characteristics were broadly comparable, except for higher NVP severity in the ondansetron group, reflected by higher PUQE scores (9.86 ± 2.66 vs. 8.59 ± 2.49; p = 0.001) and more frequent antacid use (p = 0.001). Live birth rates (95.6% vs. 94.3%) and birth weights did not differ between groups. No differences were found in neonatal complications. Major congenital malformations were comparable between groups (5.1% vs. 4.1%; p = 0.695), with no consistent pattern identified.ConclusionIn this prospective cohort, ondansetron exposure was not associated with increased risk of adverse neonatal outcomes or major congenital malformations. The sample size limits the detection of very rare outcomes, and larger studies remain warranted.
Background and Objectives: Proton Pump Inhibitors (PPIs) are the most effective agents for treating acid-related gastrointestinal disorders. The prescription of an intravenous (IV) formulation of PPIs has increased dramatically. The aims of this study were to assess the appropriateness of IV PPI use and to define the risk factors and outcomes associated with its inappropriate use. Materials and Methods: A case-control retrospective study included all the hospitalized patients who received IV PPIs was conducted. Patient health records were reviewed, data were collected covering the period of the individual patients’ admission to the hospital until discharge or death, and over the 3-month post-discharge period. The appropriateness of the IV PPI use and the resulting clinical outcomes were analyzed. Results: Overall, 540 patients were analyzed. Among them, 130/540 (24%) had inappropriate PPI use in terms of indication, dosage, and duration of treatment vs. 410 patients who had appropriate indications. Two parameters were associated with inappropriate use: congestive heart failure (OR 1.77; p = 0.02) and prescription of IV PPIs by surgeons vs. internists (OR 1.53; p = 0.05). Conclusions: Inappropriate IV PPI use is still common in daily clinical practice. Significant predictors of inappropriate use were the presence of congestive heart failure, elderly age, current use of anticoagulants and antithromotics, and the cases managed by surgeons, naturally due to suspected upper gastrointestinal bleedings.
Osteoporosis is a common, age-related disease caused by imbalanced bone remodeling. Current treatments either shut down bone resorption or robustly stimulate bone formation. Here, we describe a novel compound that inhibits osteoclast activity without causing apparent disruptions to bone formation by targeting both c-FMS (i.e., osteoclast differentiation) and αvβ3 integrin (i.e., osteoclastic bone resorption) receptors. We show that human serum albumin (HSA)-conjugated M-CSFRGD protein (M-CSFRGD-HSA) effectively inhibits the activity of both receptors, with a three-fold higher serum half-life compared to the unconjugated M-CSFRGD. We then treated ovariectomized mice with different doses of M-CSFRGD-HSA, alendronate, or a monospecific control protein. The bispecific M-CSFRGD-HSA was superior to a monospecific control in alleviating bone loss and reducing osteoclast distribution and function. M-CSFRGD-HSA and alendronate effectively prevented ovariectomy-induced bone loss, but M-CSFRGD-HSA had a milder inhibitory effect on osteoclast distribution and activity. Moreover, alendronate halted bone formation, while M-CSFRGD-HSA-treated mice showed an increased level of serum amino-terminal propeptide of type I collagen, a bone formation marker. Our data indicate that the mild reduction in osteoclast activity facilitated by the bispecific M-CSFRGD-HSA allows the maintenance of certain levels of bone formation and may be superior to treatments that induce osteoclast depletion.
Background: Over the last years, there is a dramatic increase in the use of medical cannabis products for an expanding range of clinical indications. The type of the drug product and its administration route affect substantially the rate and the extent of absorption of cannabinoids and the effects induced by them in the patients. The current challenge for the cannabis pharmaceutical industry is to develop formulations that allow predictable and stable absorption of cannabinoids. This article reports the results of the clinical trial that investigated the pharmacokinetics (PKs) of innovative cannabis products in healthy volunteers. Materials and Methods: This was a single-center study with a single-dose, randomized, crossover, partially blinded controlled design. Each of the 12 healthy volunteers received 8 different products, of the 10 products that were assessed in this trial: novel sublingual (SL) tablet, vaporizer, and rectal products, comparator products (Sativex® and oil-based oromucosal products), and placebo products. Serial blood samples were collected, plasma concentrations of the THC, 11-OH-THC, and CBD were quantified and subjected to noncompartmental PK analysis. Results: Novel medical cannabis products that were investigated in the study induced substantial exposure of the volunteers to the active ingredients, had more rapid absorption, and in some cases also less variable absorption of THC and CBD, in comparison with the approved comparison products. The bioavailability of the novel SL tablet-based and suppositories products was somewhat lower than that of the oromucosal products. The vaporizer provided immediate systemic absorption with highest maximal concentration. The safety profile of the novel cannabis products, namely vaporizer, SL tablets, and suppositories, was not inferior to the Sativex and oil-based oromucosal formulations. Conclusions: The novel cannabis products that were assessed in this study have PK properties that may be advantageous for management of specific medical conditions or in specific subgroups of patients that are prescribed medical cannabis.
Targeted therapies for prostate, breast, and ovarian cancers are based on their activity against primary tumors rather than their anti‐metastatic activity. Consequently, there is an urgent need for new agents targeting the metastatic process. Emerging evidence correlates in vitro and in vivo cancer invasion and metastasis with increased activity of the proteases mesotrypsin (prostate and breast cancer) and kallikrein 6 (KLK6; ovarian cancer). Thus, mesotrypsin and KLK6 are attractive putative targets for therapeutic intervention. As potential therapeutics for advanced metastatic prostate, breast, and ovarian cancers, we report novel mesotrypsin‐ and KLK6‐based therapies, based on our previously developed mutants of the human amyloid β‐protein precursor Kunitz protease inhibitor domain (APPI). These mutants, designated APPI‐3M (prostate and breast cancer) and APPI‐4M (ovarian cancer), demonstrated significant accumulation in tumors and therapeutic efficacy in orthotopic preclinical models, with the advantages of long retention times in vivo, high affinity and favorable pharmacokinetic properties. The applicability of the APPIs, as a novel therapy and for imaging purposes, is supported by their good safety profile and their controlled and scalable manufacturability in bioreactors.
Tissue inhibitors of metalloproteinases (TIMPs) are natural inhibitors of the matrix metalloproteinase (MMP) family of proteins, whose members are key regulators of the proteolysis of extracellular matrix components and hence of multiple biological processes. In particular, imbalanced activity of matrix metalloproteinase-14 (MMP-14) may lead to the development of cancer and cardiovascular and other diseases. This study aimed to engineer TIMP2, one of the four homologous TIMPs, as a potential therapeutic by virtue of its ability to bind to the active-site Zn2+ of MMP-14. However, the susceptibility to degradation of TIMP2 and its small size, which results in a short circulation half-life, limit its use as a therapeutic. PEGylation was thus used to improve the pharmacokinetic profile of TIMP2. PEGylation of the MMP-targeting N-terminal domain of TIMP2 (N-TIMP2), via either cysteine or lysine residues, resulted in a significant decrease in N-TIMP2 affinity toward MMP-14 or multisite conjugation and conjugate heterogeneity, respectively. Our strategy designed to address this problem was based on incorporating a noncanonical amino acid (NCAA) into N-TIMP2 to enable site-specific mono-PEGylation. The first step was to incorporate the NCAA propargyl lysine (PrK) at position S31 in N-TIMP2, which does not interfere with the N-TIMP2-MMP-14 binding interface. Thereafter, site-specific PEGylation was achieved via a click chemistry reaction between N-TIMP2-S31PrK and PEG-azide-20K. Inhibition studies showed that PEGylated N-TIMP2-S31PrK did indeed retain its inhibitory activity toward MMP-14. The modified protein also showed improved serum stability vs non-PEGylated N-TIMP2. In vivo pharmacokinetic studies in mice revealed a significant 8-fold increase in the elimination half-life of PEGylated N-TIMP2 vs the non-PEGylated protein. This study shows that site-specific bioorthogonal mono-PEGylation extends the half-life of N-TIMP2 without impairing its biological activity, thereby highlighting the advantage of this strategy for generating potent PEGylated proteins.
Importance: Lamotrigine use during breastfeeding has significantly increased in the recent years, whereas breast milk lamotrigine pharmacokinetics data are still sparse. Objectives: To assess lamotrigine exposure in breastfed infants by monitoring maternal serum and breast milk concentrations. Methods: Breastfeeding women treated with lamotrigine were recruited to this study. Maternal trough breast milk and serum samples were collected, and additional breast milk samples were collected 1, 3, 6, 9, 12 hours after lamotrigine consumption. Trough breast milk/serum ratios (M/S ratio) and breast milk area under the curve (AUC) values were calculated. Results: Twenty-one breastfeeding women were recruited to this study, and the final dataset was based on the samples collected from 17 women. Lamotrigine trough serum and mother's milk concentrations were 5.1 ± 3.3 mg/L and 3.1 ± 1.9 mg/L, respectively (mean ± standard deviation). The trough M/S ratio of lamotrigine was 0.66 ± 0.22. The lamotrigine breast milk average AUC was 41.7 ± 24.6 mg·h/L. The estimated infant dose of lamotrigine was 0.52 ± 0.31 mg/kg/day and 0.26 ± 0.15 mg/kg/day for fully and partially breastfed infants, respectively. Significant correlation was found between the maternal lamotrigine serum trough concentrations and the breast milk parameters: trough breast milk concentrations (Spearman's rho = 0.986, p < 0.0001) and breast milk AUC values (Spearman's rho = 0.941, p < 0.0001). No significant correlation was found between the maternal lamotrigine daily dose and serum trough concentrations, breast milk trough concentrations, and breast milk AUC values (Spearman's rho = 0.294, 0.285, and 0.438, p = 0.252, 0.396, and 0.078, respectively). Conclusion and Relevance: High correlation between the maternal lamotrigine trough serum concentrations and the breast milk AUC values was found, implying that monitoring the maternal lamotrigine serum concentrations can be useful for prediction of exposure of infants to lamotrigine through the breast milk. The trial was registered in the Israeli trials registry MOH_2021-09-05_010243 at September 5, 2021 Retrospectively registered https://my.health.gov.il/CliniTrials.
IL-2 is the master-regulator cytokine for T cell dependent responses and is crucial for proliferation and survival of T cells. However, IL-2-based treatments remained marginal, in part due to short half-life. Thus, we aimed to extend IL-2 half-life by flanking the IL-2 core with sequences derived from the extensively glycosylated hinge region of the NCR2 receptor. We termed this modified IL-2: “S2A”. Importantly, S2A blood half-life was extended 14-fold compared to the clinical grade IL-2, Proleukin. Low doses inoculation of S2A significantly enhanced induction of Tregs (CD4 + Regulatory T cells) in vivo, as compared to Proleukin, while both S2A and Proleukin induced low levels of CD8 + T cells. In a B16 metastatic melanoma model, S2A treatment was unable to reduce the metastatic capacity of B16 melanoma, while enhancing induction and recruitment of Tregs, compared to Proleukin. Conversely, in two autoimmune models, rheumatoid arthritis and DSS-induced colitis, S2A treatment significantly reduced the progression of disease compared to Proleukin. Our results suggest new avenues for generating long-acting IL-2 for long-standing treatment and a new technique for manipulating short-life proteins for clinical and research uses.
AIMS:In breastfeeding women, anti-epileptic therapy can lead to infant toxicities, even with newer anti-epileptic drugs such as levetiracetam. This study assessed levetiracetam breastmilk excretion and its correlation with the maternal oral dose and serum concentrations. METHODS:Women with epilepsy treated with levetiracetam were recruited to this study and completed a questionnaire. Levetiracetam concentrations were determined in serial breastmilk samples (pre-dose to 12 h post-dose period) and in a single pre-dose maternal serum sample. RESULTS:Twenty breastfeeding women and 21 infants (one woman with twins; 16 fully and five partially breastfed infants) participated in this study. The trough breastmilk/serum ratio of levetiracetam was 0.98 ± 0.20. The infant levetiracetam daily dose was 5.39 ± 1.96 and 2.70 ± 0.98 mg. kg-1. d-1 , and the relative infant dose (RID) was 13.8 ± 3.1% and 6.9 ± 1.6% in the fully and partially breastfed infants, respectively. Substantial correlations between the levetiracetam dose, maternal serum and breastmilk trough concentrations, and breastmilk AUC values were found. Three women reported somnolence in their fully breastfed infants, which resolved shortly after switching to partial breastfeeding. All the infants gained weight according to their age. CONCLUSIONS:Infant levetiracetam exposure via the breastmilk was close to the safety thresholds (trough breastmilk/serum ratio slightly below 1, RID > 10% in fully breastfed infants), and infant somnolescence reports could be related to exposure of the infants to levetiracetam via breastmilk. Further studies are warranted to reveal the short- and long-term safety of levetiracetam in breastfeeding.
Oral carotenoids and polyphenols have been suggested to induce photo-protective effects. The aim of the study was to test whether the combination of carotenoids and polyphenols produce greater protective effects from UV-induced damage to skin cells. Such damage is characterized by inflammation and oxidative stress; thus, the photo-protective effect can be partially explained by modulating the nuclear factor kappa B (NFκB) and antioxidant response element/Nrf2 (ARE/Nrf2) transcription systems, known as important regulators of these two processes. Indeed, it was found in keratinocytes that carotenoids and polyphenols inhibit UVB-induced NFκB activity and release of cytokine IL-6. A combination of tomato extract with rosemary extract inhibited UVB-induced release of IL-6 more than each of the compounds alone. Moreover, this combination synergistically activated ARE/Nrf2 transcription systems. Inflammatory cytokines such as IL-6 and TNFα induce the expression of matrix metalloproteinases (MMPs), which leads to collagen breakdown; thus, it is important to note that carnosic acid reduced TNFα-induced MMP-1 secretion from human dermal fibroblasts. The in vitro results suggest beneficial effects of phytonutrient combinations on skin health. To assure that clinical experiments to prove such effects in humans are feasible, the human bioavailability of carotenoids from tomato extract was tested, and nearly a twofold increase in their plasma concentrations was detected. This study demonstrates that carotenoids and polyphenols cooperate in balancing UV-induced skin cell damage, and suggests that NFκB and ARE/Nrf2 are involved in these effects.
Objective: To characterize the differences in stability of L-adrenaline in adrenaline ampoules from different manufacturers that are used by the Israel Defense Forces (IDF). Methods: Adrenaline ampoules from three different vendors (Products A, B and C; 52, 13, and 19 batches, respectively) were purchased by the IDF and were stored under the recommended storage conditions (room temperature) for different time periods. The content of L-adrenaline in these samples was determined using a chiral high-performance liquid chromatography (HPLC) assay with UV detection. Results: The three analyzed drug products showed very dissimilar patterns of L-adrenaline degradation. The content of L-adrenaline in Product C was variable and declined below the 85% threshold much earlier than at the end of the 24-months storage period. Products A and B had less variable content of L-adrenaline and were more stable. Conclusion: L-adrenaline is prone to degradation in solution. Its content in adrenaline ampoules from certain vendors can decline rapidly, below the stipulated threshold, and compromise their clinical effectiveness (e. g., during resuscitation). Stability of adrenaline ampoules from individual vendors should be analyzed at different storage conditions, using a chiral HPLC-based assay, to define the shelf-life period that can differ substantially between the vendors.
The clinical efficacy of the PEGylated doxorubicin liposomes (PLD) is limited by low tumor accumulation and limited intra-tumoral disposition. Decoration with the cell penetration enhancers (CPEs) can increase the PLD permeability via the biological barriers, however at the expense of enhanced distribution to the non-target organs and tissues, and may interfere with their tumor accumulation and with the resulting anti-cancer effects. We investigated the effect of the surface CPE agent tetraArg-[G-1] -distearoyl glycerol (DAG-Arg(4)) on the systemic and intra-tumoral accumulation of PLD, using a 4 T1-Luc murine orthotopic model of breast cancer, using several analytical approaches. CPE-decorated liposomes undergo efficient in vitro endocytosis, and delivered doxorubicin to the cell nuclei. In vivo, they had lower tumor and spleen accumulation, similar liver accumulation, and higher lung accumulation, as compared to those of the PLD. Despite the lower tumor accumulation, CPE-decorated liposomes induced more prominent in vivo anti-cancer effects, as compared to the PLD, apparently ascribable to the higher intra-tumoral permeability mediated by the CPE surface residues. Overall, liposomes decoration with the CPE residues had mostly beneficial effects on their systemic and intra-tumoral disposition. The mechanisms of the CPE-mediated effects on the liposome disposition should be further assessed with additional experimental models using robust analytical methods with high spatial resolution.
Oxidative stress is implicated in the pathogenesis of essential hypertension, a risk factor for cardiovascular morbidity and mortality. Tomato carotenoids such as lycopene and the colorless carotenoids phytoene and phytofluene induce the antioxidant defense mechanism. This double-blind, randomized, placebo-controlled study aimed to find effective doses of Tomato Nutrient Complex (TNC) to maintain normal blood pressure in untreated hypertensive individuals. The effect of TNC treatment (5, 15 and 30 mg lycopene) was compared with 15 mg of synthetic lycopene and a placebo over eight weeks. Results indicate that only TNC treatment standardized for 15 or 30 mg of lycopene was associated with significant reductions in mean systolic blood pressure (SBP). Treatment with the lower dose standardized for 5 mg of lycopene or treatment with 15 mg of synthetic lycopene as a standalone had no significant effect. To test carotenoid bioavailability, volunteers were treated for four weeks with TNC providing 2, 5 or 15 mg lycopene. The increase in blood levels of lycopene, phytoene, and phytofluene was dose dependent. Results suggest that only carotenoid levels achieved by the TNC dose of 15 mg lycopene or higher correlate to a beneficial effect on SBP in hypertensive subjects while lower doses and lycopene alone do not.
Background: Epilepsy is one of the most common chronic neurological conditions and its treatment during pregnancy is challenging. Levetiracetam (LEV) is an antiepileptic medication frequently used during pregnancy. Only a few small studies have been published on LEV monitoring during pregnancy, demonstrating decreased serum LEV levels during the first and second trimester; however, the most significant decrease was observed during the third trimester of pregnancy. In this study we aimed to evaluate LEV pharmacokinetics during different stages of pregnancy. Methods: We followed up and monitored serum levels of pregnant women treated with LEV for epilepsy. Results: Fifty-nine women with 66 pregnancies during the study period were included. The lowest raw LEV serum concentrations were observed during the first trimester. Compared with the pre-pregnancy period, raw serum concentration was lower by 5.76 mg/L [95% confidence interval (CI) (2.78, 8.75), p = 0.039] during the first trimester. Comparing the decrease in the first trimester with either the second or the third, no significant changes were observed (p = 0.945, p = 0.866). Compared with pre-pregnancy measurements, apparent clearance was increased by 71.08 L/day [95%CI (16.34, 125.83), p = 0.011] during the first trimester. About 30% of LEV serum levels during pregnancy were below the laboratory quoted reference range. Conclusions: Raw LEV serum levels tend to decrease during pregnancy, mainly during the first trimester contrary to previous reports. Monitoring of LEV serum levels is essential upon planning pregnancy and thereafter if pre-pregnancy LEV levels are to be maintained. However, more studies are needed to assess the correlation with clinical outcome.
The effect of topical co-administration of promoter drugs with paclitaxel to increase anti-tumor effects of paclitaxel was investigated. Mice with orthotopic 4T1-Luc breast cancer received single intra-tumoral injection of a polymeric formulation with paclitaxel and a specific promoter drug. Several promoter drugs were evaluated, including: dexamethasone, losartan, nicotinamide, Azone, and oleic acid. Dexamethasone exhibited the highest effect on paclitaxel anti-tumor activity, in a dose-dependent fashion. However, this effect was accompanied by systemic effects of dexamethasone, and inability to prevent tumor metastasis to the lungs. Topical co-administration of promoter drugs with anti-cancer agents can enhance their anti-tumor effects. Further investigations are needed to identify the most efficient combinations of promoter and anti-cancer drugs, and their suitability for the clinical management of the breast cancer disease.
Toxins and venoms produced by different organisms contain peptides that have evolved to have highly selective and potent pharmacological effects on specific targets for protection and predation. Several toxin-derived peptides have become drugs and are used for the management of diabetes, hypertension, chronic pain, and other medical conditions. Despite the similarity in their composition (amino acids as the building blocks), toxin-derived peptide drugs have very profound differences in their structure and conformation, in their physicochemical properties (that affect solubility, stability, etc.), and subsequently in their pharmacokinetics (the processes of absorption, distribution, metabolism, and elimination following their administration to patients). This review summarizes and critically analyzes the pharmacokinetic properties of toxin-derived peptide drugs: (1) the relationship between the chemical structure, physicochemical properties, and the pharmacokinetics of the specific drugs, (2) the major pharmacokinetic properties and parameters of these drugs, and (3) the major pharmacokinetic variability factors of the individual drugs. The structural properties of toxin-derived peptides affect their pharmacokinetics and pose some limitations on their clinical use. These properties should be taken into account during the development of new toxin-derived peptide drugs, and for the efficient and safe use of the clinically approved drugs from this group in the individual patients.
Targeted delivery to the cell nucleus can enhance the efficiency of drugs with nuclear site of action (some anti-cancer agents, DNA drugs, etc.), and can reduce their toxicity. Such targeting can be attained using nano-drug delivery systems (nano-DDSs) decorated with nuclear targeting sequences (such as nuclear localization sequence peptides, NLS). Several types of nano-DDSs decorated with NLS peptides were designed, but their investigation usually did not include quantitate analysis of the decoration efficiency and its correlation with the nano-DDSs intracellular localization. Thus, the major mechanisms and limiting factors of the nano-DDSs nuclear targeting are largely unknown yet. In this study, we report quantitative data for specific nano-formulation (CdSe-ZnS quantum dots) that include the efficiencies of its decoration with NLS residues and of its nuclear and perinuclear targeting, and demonstrate correlation between these parameters. For instance, QDs decorated with 83, 246, and 265 NLS peptides accumulated efficiently in the nucleus of HeLa cells or its vicinity (an average of 30.4%, 43.3%, and 49.0% of the intracellular QDs, respectively). On the other hand, QDs decorated with 63, 231, and 308 scrambled peptides accumulated in the nucleus of HeLa cells or its vicinity to a much lower extent (an average of 17.3%, 21.1%, and 25.5% of the intracellular QDs, respectively). Thus, results of our study provide important insights into the structure-activity correlations (i.e., the relationships between the formulation properties and the intracellular fate of nano-DDSs) of nuclear-targeted drug delivery. We plan to apply the research tools that were developed in the course of this and our previous studies to investigate the nuclear and perinuclear targeting activities of different NLS sequences, and to investigate the effects of nano-DDSs size, charge, shape, decoration efficiency with nuclear targeting sequences, and other structural factors on nuclear and perinuclear targeting efficiency.
AIMS The aim of the study was to analyze the interaction between celecoxib and low dose aspirin for COX-1 binding and its consequences on the aspirin-mediated antiplatelet effects. METHODS We investigated ex vivo the interaction between celecoxib and aspirin for COX-1 binding and measured the resulting antiplatelet effects. We applied mechanism-based pharmacokinetic-pharmacodynamic (PKPD) modelling to analyze these data and to predict in vivo platelet aggregation for different doses and administration schedules of aspirin and celecoxib. RESULTS The predictions of the PK-PD model were consistent with results from previous studies that investigated interaction between aspirin and celecoxib. The modelling results indicate that celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. The extent of this interaction can be substantial (up to 15% increase in platelet aggregation by 200 mg day(-1) celecoxib when combined with low dose aspirin) during the first days of aspirin administration in patients who are already treated with celecoxib, and it cannot be prevented by separate administration of the interacting drugs. CONCLUSIONS At the recommended therapeutic doses, celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. Patients receiving a combination of low dose aspirin and the recommended doses of celecoxib were not identified to have increased risk of cardiovascular and cerebrovascular events due to competition between these drugs for COX-1 binding. Interaction between low dose aspirin and other COX-2 inhibitors and its clinical consequences requires further investigation.