Defining the COX inhibitor selectivity of NSAIDs: implications for understanding toxicity

Concomitant NSAID use during antipsychotic treatment and risk of 2-year relapse - a population-based study of 16,253 incident patients with schizophrenia

OBJECTIVE

Clinical trials have indicated antipsychotic effects of non-steroidal anti-inflammatory drugs (NSAIDs) among incident patients with schizophrenia. We aimed to study, in a population-based setting, whether concomitant use of NSAIDs or paracetamol, changed 2-year relapse risk for schizophrenia.

METHODS

We identified all incident patients with schizophrenia in Denmark diagnosed 1996-2012 initiating antipsychotic treatment within the year after diagnosis. We calculated concomitant treatment intervals for antipsychotic and NSAID or paracetamol use. Hazard rate ratios (HRR) were estimated using Cox regression adjusted for important covariates.

MAIN OUTCOME MEASURES

2-year relapse, i.e. (re)-hospitalizations with schizophrenia.

RESULTS

Among 16,235 incident patients with schizophrenia using antipsychotics, 1480 (9.1%) used NSAIDs and 767 (4.7%) paracetamol. Concomitant use of NSAIDs was associated with an increased risk of schizophrenia relapse (HRR = 1.21; 95%-CI = 1.11-1.31), particularly associated with acetylsalicylic acid and diclofenac. Concomitant use of paracetamol was not associated with schizophrenia relapse (HRR = 0.97; 95%-CI = 0.87-1.08). Subgroup analyses showed that individuals with somatic comorbidity and NSAID use had an increased relapse-risk, except for individuals with a prior hospital diagnosis for musculoskeletal disease and NSAID use who had a decreased relapse-risk (HRR = 0.82; 95%-CI = 0.71-0.94).

CONCLUSIONS

The increased relapse risk associated with concomitant NSAID use among incident patients with schizophrenia may indicate a potential impact of underlying somatic comorbidity.

Evolution to low-dose NSAID therapy

All NSAIDs are to varying degrees associated with gastrointestinal, cardiovascular and renal adverse effects (AEs). Differences in selectivity for inhibition of the COX isozymes (COX-1/COX-2) have been used as an indicator of the likelihood of experiencing an AE, but the measure of 'selectivity' commonly used is less than desirable, and selectivity has not yielded unequivocal superior safety. Recent guidelines recommend that NSAIDs be used at the lowest effective dose and for the shortest period of time. In response, 'low-dose' NSAID formulations have been developed. Such formulations may help by reducing overall systemic exposure, thereby reducing the frequency or severity of AEs. It seems timely to review the need, rationale and application of such an approach.

Oxaprozin-Loaded Lipid Nanoparticles towards Overcoming NSAIDs Side-Effects

PURPOSE

Nanostructured Lipid Carriers (NLCs) loading oxaprozin were developed to address an effective drug packaging and targeted delivery, improving the drug pharmacokinetics and pharmacodynamics properties and avoiding the local gastric side-effects. Macrophages actively phagocyte particles with sizes larger than 200 nm and, when activated, over-express folate beta receptors - features that in the case of this work constitute the basis for passive and active targeting strategies.

METHODS

Two formulations containing oxaprozin were developed: NLCs with and without folate functionalization. In order to target the macrophages folate receptors, a DSPE-PEG2000-FA conjugate was synthesized and added to the NLCs.

RESULTS

These formulations presented a relatively low polydispersity index (approximately 0.2) with mean diameters greater than 200 nm and zeta potential inferior to -40 mV. The encapsulation efficiency of the particles was superior to 95% and the loading capacity was of 9%, approximately. The formulations retained the oxaprozin release in simulated gastric fluid (only around 10%) promoting its release on simulated intestinal fluid. MTT and LDH assays revealed that the formulations only presented cytotoxicity in Caco-2 cells for oxaprozin concentrations superior to 100 μM. Permeability studies in Caco-2 cells shown that oxaprozin encapsulation did not interfered with oxaprozin permeability (around 0.8 × 10(-5) cm/s in simulated intestinal fluid and about 1.45 × 10(-5) cm/s in PBS). Moreover, in RAW 264.7 cells NLCs functionalization promoted an increased uptake over time mainly mediated by a caveolae uptake mechanism.

CONCLUSIONS

The developed nanoparticles enclose a great potential for oxaprozin oral administration with significant less gastric side-effects.

Inflammation and depression: combined use of selective serotonin reuptake inhibitors and NSAIDs or paracetamol and psychiatric outcomes

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol have been shown to yield the potential of adjunctive antidepressant treatment effects to selective serotonin reuptake inhibitors (SSRIs); however, when investigating treatment effects of concomitant use, simultaneous evaluation of potential adverse events is important. The objective was thus to investigate treatment effectiveness and safety aspects of concomitant SSRI use with NSAIDs or paracetamol.

METHODS

Within a 25% random sample of the Danish population, we identified all incident SSRI users between 1997 and 2006 (N = 123,351). Effectiveness and safety measures were compared between periods of SSRI use only and periods of combined SSRI and NSAID or paracetamol use by applying Cox regression.

RESULTS

Among 123,351 SSRI users (follow-up: 53,697.8 person-years), 21,666 (17.5%) used NSAIDs and 10,232 (8.3%) paracetamol concomitantly. Concomitant NSAID use increased the risk of any psychiatric contact [Hazard rate ratio (95%-confidence interval): 1.22 (1.07; 1.38)] and with depression [1.31 (1.11; 1.55)]. Low-dose acetylsalicylic acid reduced the risk of psychiatric contact in general [0.74 (0.56; 0.98)] and with depression [0.71 (0.50; 1.01)]. Ibuprofen reduced the risk of psychiatric contacts [0.76 (0.60; 0.98)]. Concerning safety, paracetamol was associated with increased mortality [3.18 (2.83; 3.58)], especially cardiovascular [2.51 (1.93; 3.28)]. Diclofenac [1.77 (1.22; 2.55)] and the selective COX-2 inhibitors [1.75 (1.21; 2.53)] increased mortality risks.

CONCLUSIONS

Concomitant use of SSRIs and NSAIDs occurred frequently, and effectiveness and safety outcomes varied across individual NSAIDs. Especially low-dose acetylsalicylic acid may represent an adjunctive antidepressant treatment option. The increased mortality risk of concomitant use of paracetamol needs further investigation.

Global epidemiology of hepatocellular carcinoma: an emphasis on demographic and regional variability

Liver cancer is the second leading cause of global cancer mortality. The major risk factors for hepatocellular carcinoma (HCC) are being addressed with success by prevention efforts. Vaccination against hepatitis B virus has reduced incidence of HCC in Taiwan and is partly responsible for lower rates in China. New infections with hepatitis C virus are low in developed countries because of prevention of posttransfusion infections and reduced exposure to HCV by drug users. Aflatoxin exposure has been reduced by better grain storage and dietary changes. Obesity, metabolic syndrome, and diabetes are increasing in developed and developing countries and will lead to more cases of HCC.

Risk of stroke associated with nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs), both cyclooxygenase (COX)-2-selective and nonselective agents, have been associated with the increased risk of adverse cardiovascular events. The majority of studies have focused on myocardial infarction as the primary cardiovascular outcome. However, the association between NSAIDs and the risk of stroke events is not as clear, although an understanding of this association is important since stroke continues to be a significant cause of morbidity and mortality. Various factors may contribute to an association between NSAIDs and stroke, including hypertension and thrombosis. Additionally, the risk may vary with different NSAID types. In this review, we discuss the relevant literature assessing the possible association between NSAID use and stroke events, along with the potential mechanisms and the possible directions for future study.

Prostanoid receptor EP2 as a therapeutic target

Cycoloxygenase-2 (COX-2) induction is prevalent in a variety of (brain and peripheral) injury models where COX-2 levels correlate with disease progression. Thus, COX-2 has been widely explored for anti-inflammatory therapy with COX-2 inhibitors, which proved to be effective in reducing the pain and inflammation in patients with arthritis and menstrual cramps, but they have not provided any benefit to patients with chronic inflammatory neurodegenerative disease. Recently, two COX-2 drugs, rofecoxib and valdecoxib, were withdrawn from the United States market due to cardiovascular side effects. Thus, future anti-inflammatory therapy could be targeted through a specific prostanoid receptor downstream of COX-2. The PGE2 receptor EP2 is emerging as a pro-inflammatory target in a variety of CNS and peripheral diseases. Here we highlight the latest developments on the role of EP2 in diseases, mechanism of activation, and small molecule discovery targeted either to enhance or to block the function of this receptor.

Nonsteroidal anti-inflammatory drug use, chronic liver disease, and hepatocellular carcinoma

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce chronic inflammation and risk of many cancers, but their effect on risk of hepatocellular carcinoma (HCC) and death due to chronic liver disease (CLD) has not been investigated.

METHODS

We analyzed prospective data on 300504 men and women aged 50 to 71 years in the National Institutes of Health-AARP Diet and Health Study cohort and linked self-reported aspirin and nonaspirin NSAID use with registry-confirmed diagnoses of HCC (n=250) and death due to CLD (n=428, excluding HCC). We calculated hazard rate ratios (RRs) and their two-sided 95% confidence intervals (CIs) using Cox proportional hazard regression models with adjustment for age, sex, race/ethnicity, cigarette smoking, alcohol consumption, diabetes, and body mass index. All tests of statistical significance were two-sided.

RESULTS

Aspirin users had statistically significant reduced risks of incidence of HCC (RR = 0.59; 95% CI = 0.45 to 0.77) and mortality due to CLD (RR = 0.55; 95% CI = 0.45 to 0.67) compared to those who did not use aspirin. In contrast, users of nonaspirin NSAIDs had a reduced risk of mortality due to CLD (RR = 0.74; 95% CI= 0.61 to 0.90) but did not have lower risk of incidence of HCC (RR = 1.08; 95% CI = 0.84 to 1.39) compared to those who did not use nonaspirin NSAIDs. The risk estimates did not vary in statistical significance by frequency (monthly, weekly, daily) of aspirin use, but the reduced risk of mortality due to CLD was statistically significant only among monthly users of nonaspirin NSAIDs compared to non-users.

CONCLUSIONS

Aspirin use was associated with reduced risk of developing HCC and of death due to CLD whereas nonaspirin NSAID use was only associated with reduced risk of death due to CLD.

Cyclooxygenase (COX) Inhibitors and the Newborn Kidney

This review summarizes our current understanding of the role of cyclo-oxygenase inhibitors (COXI) in influencing the structural development as well as the function of the developing kidney. COXI administered either during pregnancy or after birth can influence kidney development including nephronogenesis, and can decrease renal perfusion and ultrafiltration potentially leading to acute kidney injury in the newborn period. To date, which COX isoform (COX-1 or COX-2) plays a more important role in during fetal development and influences kidney function early in life is not known, though evidence points to a predominant role for COX-2. Clinical implications of the use of COXI in pregnancy and in the newborn infant are also evaluated herein, with specific reference to the potential effects of COXI on nephronogenesis as well as newborn kidney function.