Aspirin in essential thrombocythemia. For whom? What formulation? What regimen?

Essential thrombocythemia (ET) is a BCR-ABL1-negative myeloproliferative neoplasm, the most common clinical manifestations of which include arterial and venous thrombosis, bleeding and vasomotor/microvascular disturbances. Low-dose (81-100 mg) aspirin once daily, which irreversibly inhibits platelet thromboxane A2 (TxA2) production by acetylating cyclo-oxygenase-1, is the recommended treatment for the control of vascular events in all ET risk categories, except patients at very low risk, who need aspirin for treatment of vasomotor/microvascular disturbances only. Simple observation should be preferred over aspirin prophylaxis in low-risk patients with platelet counts >1,000x109/L or harboring CALR mutations. Plain aspirin should be preferred over enteric coated aspirin because some ET patients display poor responsiveness ("resistance") to the latter. When treated with a once daily aspirin regimen, adequate inhibition of platelet TxA2 production (measured as serum thromboxane B2 level) does not persist for 24 h in most patients. This phenomenon is associated with the patients' platelet count and the number (but not the fraction) of circulating immature reticulated platelets with non-acetylated cyclo-oxygenase-1 and is therefore consequent to high platelet production (the hallmark of ET), rather than increased platelet turnover (which is normal in ET). Twice daily aspirin administration overcame this problem and proved safe in small studies. Although additional data on gastrointestinal tolerability will be useful, the twice daily regimen could already be implemented in clinical practice, considering its favorable risk/benefit profile. However, patients whose platelet count has been normalized could still be treated with the once daily regimen, because they would otherwise be unnecessarily exposed to a potential small risk of gastrointestinal discomfort.

HPLC and GC Characterization of Dicliptera bupleuroides Aerial Parts and Evaluation of Its Anti-Inflammatory Potential in Vitro, in silico and in Vivo Using Carrageenan and Formalin Induced Inflammation in Rat Models.

The current study aimed to evaluate the anti-inflammatory activity of Dicliptera bupleuroides Nees aerial parts methanol extract and its different fractions namely hexane, chloroform, ethyl acetate and butanol in vitro using cyclooxygenase inhibitory assay (COX-2). In vivo anti-inflammatory evaluation was performed using carrageenan and formalin induced inflammation in rat models followed by molecular docking. High performance liquid chromatography (HPLC) and gas chromatography coupled with mass chromatography (GC/MS) analyses were used for chemical analyses of the tested samples. The tested samples showed significant inhibition in COX-2 inhibitory assay where methanol extract (DBM) showed the highest inhibitory potential at 100 µg/mL estimated by 67.86 %. At a dose of 400 mg/kg, all of the examined samples showed pronounced results in carrageenan induced acute inflammation in rat model at 4th h interval with DBM showed the highest efficiency displaying 65.32 % inhibition as compared to the untreated rats. Formalin model was employed for seven days and DBM exhibited 65.33 % and 69.39 % inhibition at 200 and 400 mg/kg, respectively approaching that of the standard on the 7th day. HPLC revealed the presence of caffeic acid, gallic acid and sinapic acid, quercetin and myricetin in DBM. GC/MS analysis of its hexane fraction revealed the presence of 16 compounds belonging mainly to fatty acids and sterols that account for 85.26 % of the total detected compounds. Molecular docking showed that hexadecanoic acid followed by decanedioic acid and isopropyl myristate showed the best fitting within cyclooxygenase-II (COX-II) while nonacosane followed by hexatriacontane and isopropyl myristate revealed the most pronounced fitting within the 5-lipoxygenase (5-LOX) active sites. Absorption, metabolism, distribution and excretion and toxicity prediction (ADMET/ TOPKAT) concluded that most of the detected compounds showed reasonable pharmacokinetic, pharmacodynamic and toxicity properties that could be further modified to be more suitable for incorporation in pharmaceutical dosage forms combating inflammation and its undesirable consequences.

Effect of digoxin, sodium valproate, and celecoxib on the cerebral cyclooxygenase pathway and neuron-specific enolase under the pentylenetetrazole-induced kindling in mice.

Neuroinflammation plays an important role in the pathogenesis of epilepsy, so it is necessary to clarify the influence of standard antiepileptic drugs as well as adjuvant agents (e.g., cardiac glycoside digoxin, which previously showed a clear anticonvulsant potential) on cyclooxygenase pathway and neuron-specific enolase under the conditions of chronic epileptogenesis. The aim of the article is to determine the effect of digoxin, sodium valproate, and celecoxib per se, as well as the combination of digoxin with sodium valproate on the content of cyclooxygenase 1 and 2 types, prostaglandins E2, F2α, I2, thromboxane B2, 8-isoprostane and neuron-specific enolase in the brain of mice in the pentylenetetrazole-induced kindling model. It was found that only the combination of sodium valproate with digoxin provides a complete protective effect (absence of seizures) and shows the clearest influence on neuroinflammation markers and neuronal damage than monotherapy with each of these drugs and celecoxib, which appeared to be an ineffective anticonvulsant. The obtained results indicate that digoxin is a promising adjuvant drug to classical antiepileptic drugs (mostly sodium valproate) in epilepsy treatment.c.

Does Early Neonatal Thrombocytopenia Affect Ductal Therapeutic Response to Acetaminophen in Preterm Neonates?

OBJECTIVE: Perinatal thrombocytopenia has been shown to affect responsiveness to therapeutic ductal closure with cyclooxygenase (COX) inhibitors. This has not been studied in responsiveness to acetaminophen, which has less effect on platelet function. The objective of this study was to evaluate whether thrombocytopenia affects ductal responsiveness to acetaminophen. STUDY DESIGN: This study was a retrospective review of preterm neonates <1,500 g. Echocardiograms were performed within the first week of life; if ductal status was found to be hemodynamically significant, infants were treated with acetaminophen. RESULTS: We studied 254 infants. Fifty-seven of these (22%) had a hemodynamically significant patent ductus arteriosus (hsPDA) and were treated with acetaminophen. Forty (70%) of those treated responded with ductal closure after one to two courses of acetaminophen. Seventeen infants were considered nonresponsive, requiring the addition of ibuprofen and/or surgical ligation. Sixty seven of the 254 infants (26%) developed moderate thrombocytopenia (platelets <100,000) within the first 10 days of life, more within the hsPDA group (54 vs. 18% p < 0.001); however, no differences in platelet-related parameters were observed between those who did and did not respond to acetaminophen treatment when comparing infants with hsPDA. Twenty-six of the 67 thrombocytopenic infants were already thrombocytopenic prior to acetaminophen treatment, and 19 of these 26 (73%) with pretreatment thrombocytopenia responded to acetaminophen treatment-with the overall response rate of 70%. CONCLUSIONS: This study is the first to document that, in contrast to the COX inhibitors, there is no association between early neonatal thrombocytopenia and ductal therapeutic responsiveness to acetaminophen. KEY POINTS: · Perinatal thrombocytopenia affects ductal closure with COX inhibitors.. · In contrast to the COX inhibitors, acetaminophen responsiveness is not affected by thrombocytopenia.. · Acetaminophen can be recommended to close hsPDA in the presence of thrombocytopenia..

[Current status of breast cancer chemoprevention]. / Quimioprevenção do câncer de mama.

Chemoprevention is defined as the use of natural or synthetic chemical agents to reverse, suppress or prevent carcinogenic progression of invasive cancer. Drugs that act as chemoprevention agents for breast cancer are divided into two major groups: drugs that prevent Estrogen Receptor (ER)-positive breast cancers [selective estrogen receptor modulators (SERM), aromatase inhibitors GnKH agonists and phytoestrogens] and drugs that prevent ER-negative breast cancers [cyclooxygenase-2 (COX-2) inhibitors, retinoids, statins, receptor tyrosine, kinase inhibitors, monoclonal antibody against HER-2 and telomerase inhibitors]. Results from the NSABP Study of Tamoxifen and Raloxifene (STAR), which compared the risk-reducing efficacy as well as toxicity of these two SERMs in a similar high-risk for breast cancer population, showed that Raloxifene is as effective as Tamoxifen in reducing the risk of non-invasive breast cancer (p=.83). It has a statistically significant lower risk of thromboembolic events and cataracts, however a non- statistically significant higher risk of noninvasive breast cancer. Based on promising data involving reduction of contralateral breast cancer risk in adjuvant studies, several aromatase inhibitors, including letrozole, anastrozole and exemestane, are being included in trials to evaluate their efficacy in breast cancer prevention in both case-control and cohort studies As such randomized studies to confirm this efficacy are needed. Positive results of several recent clinical trials for preventing breast cancer in high-risk populations suggest that chemoprevention is a rational and attractive strategy.

Cyclooxygenase and nitric oxide systems in the gut as therapeutic targets for safer anti-inflammatory drugs.

After a decade of intense pharmacological and drug development activity by the pharmaceutical industry, compounds derived from two key strategies for reducing gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs) have been subjected to rigorous clinical appraisal. Despite the undoubted therapeutic and commercial success of the selective cyclooxygenase (COX)-2 inhibitors, known as the coxibs, with second-generation compounds already approved and launched, some concerns over their full gastrointestinal profile still linger, while the cardiovascular safety of this class has become a key issue. Likewise, Phase II evaluation of compounds incorporating a nitric oxide (NO)-donating moiety into standard NSAIDs (the NO-NSAIDs or CINODs) has created recent controversy over the full clinical profile of these compounds. Other approaches such as NO-COX-2 inhibitors and dual COX-lipoxygenase inhibitors are already warranting interest. It might therefore be too early to predict the eventual winning strategy for safer anti-inflammatory drugs.

Midkine and cyclooxygenase-2 promoters are promising for adenoviral vector gene delivery of pancreatic carcinoma.

Midkine (MK), a heparin binding growth factor, and cyclooxygenase-2 (COX-2), a key enzyme in the conversion of arachidonic acid to prostaglandin, are both up-regulated at the mRNA or protein level in many human malignant tumors. Here, we investigated the tumor specificity of both MK and COX-2 promoters in human pancreatic cancer, with the aim to improve the selectivity of therapeutic gene expression. We constructed recombinant adenoviral (Ad) vectors containing either the luciferase (Luc) reporter gene under the control of the COX-2 or MK promoter or the herpes simplex virus thymidine kinase (HSV Tk) gene under the control of the COX-2 promoter and compared the expression with the cytomegalovirus (CMV) promoter. AdMKLuc achieved moderate to relatively high activity upon infection to both primary and established pancreatic carcinoma cells. Of the two COX-2 promoter regions (COX-2M and COX-2L), both revealed a high activity in primary pancreatic carcinoma cells, whereas in the established pancreatic carcinoma cell lines, COX-2L has an approximately equal high activity compared to CMV. In addition, both AdCOX-2M Tk and AdCOX-2L Tk induced marked cell death in response to ganciclovir (GCV) in three of four established pancreatic carcinoma cell lines. From these results, and because it has been reported that AdMKTk and AdCOX-2L Tk in combination with GCV did not reveal significant liver toxicity, we conclude that the MK as well as the COX-2 promoters are promising tumor-specific promoters for Ad vector-based gene therapy of pancreatic cancer.

Potential effect of cyclooxygenase-2-specific inhibitors on the prevention of colorectal cancer: a cost-effectiveness analysis.

PURPOSE: To estimate the potential cost-effectiveness of colorectal cancer chemoprevention with cyclooxygenase-2-specific inhibitors (COX-2 inhibitors). METHODS: Using a decision analytic Markov model, we estimated the discounted cost per life-year saved for three strategies: a COX-2 inhibitor alone; as an adjunct to colonoscopy every 10 years in persons at average risk of colorectal cancer; and as an adjunct to colonoscopy every 5 years in persons with first-degree relatives who had colorectal cancer. RESULTS: In the base case, the incremental cost per life-year saved with a COX-2 inhibitor alone compared with no screening was 233,300 dollars in persons at average risk of colorectal cancer and 56,700 dollars in persons with 2 first-degree relatives who had the disease. Chemoprevention was both less effective and more costly than screening. The incremental cost per life-year saved with a COX-2 inhibitor as an adjunct to screening was 823,800 dollars in persons at average risk and 404,700 dollars in persons with 2 first-degree relatives who had colorectal cancer. Combining a COX-2 inhibitor with less frequent screening was not as cost-effective as screening at currently recommended intervals. Cost-effectiveness estimates were highly sensitive to the cost of COX-2 inhibitors and their effect on the risk of cancer. CONCLUSION: Chemoprevention of colorectal cancer with COX-2 inhibitors is likely to incur substantially higher costs per life-year saved than are currently recommended screening strategies. COX-2 inhibitor use as an adjunct to screening may increase life expectancy, although at prohibitive costs, and is unlikely to result in less frequent screening.

Role of COX-2 inhibitors in the evolution of acute pain management.

Management of acute postoperative pain remains suboptimal: nearly 80% of patients report moderate to extreme pain following surgery. New pain management paradigms incorporate multimodal analgesia, using a combination of analgesics throughout the perioperative period to control nociceptive and centrally-stimulated pain. Nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) have a role in postoperative pain management, but concerns about increased bleeding and inhibited wound healing and bone fusion have limited their use. Cyclooxygenase (COX)-2-selective inhibitors (coxibs) offer the peripheral pain-relieving benefits of nonselective NSAIDs but with fewer adverse GI effects; they also may have a role in central sensitization. Clinical trials have demonstrated the efficacy and safety of celecoxib and rofecoxib for postoperative pain and for preemptive analgesia, and newer agents such as valdecoxib and etoricoxib also have demonstrated efficacy in these settings. In addition to their selectivity for the COX-2 isozyme overall, unique differences among the coxibs, such as in plasma half-life, may impart certain clinical advantages.

Pharmacoeconomics of coxib therapy.

The economic evaluation of health care programs is undertaken to assess health care costs and benefits. Part of the goal of cost-effectiveness analysis is to maximize health benefits given the constraint of limited health care resources. The identification of costs is critical in a cost-effectiveness analysis of clinical interventions. The recent introduction of the cyclooxygenase (COX)-2-selective inhibitors, coxibs, for treatment of rheumatoid arthritis, osteoarthritis, and acute pain gives rise to cost-effectiveness issues. These new agents provide similar efficacy with fewer gastrointestinal events compared with nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), but are more expensive on a per-dose basis. However, several modeled cost analyses have suggested that COX-2 inhibitors are cost effective in subsets of patients because they are associated with fewer downstream costs, particularly medical and surgical treatment of gastrointestinal adverse effects. Three cost-effectiveness models of interventions for rheumatoid arthritis and osteoarthritis, including COX-2 inhibitors, are reviewed. Prospective clinical investigation of the potential costs and benefits of these new agents is necessary to further support these findings.

Cox-2 inhibitors and other nonsteroidal anti-inflammatory drugs in the treatment of pain in the elderly.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed therapies for acute and chronic pain in the elderly. NSAIDs are effective in treating many disorders, but their use often is limited by toxicities, especially gastrointestinal and renal toxicity. COX-2 inhibitors are a major therapeutic advance, providing the analgesic and anti-inflammatory activity of NSAIDs, with a significant improvement in gastrointestinal safety. These new agents may be ideal therapies for older patients at risk for NSAID-related gastrointestinal toxicity.

COX-1, COX-2 and articular joint disease: a role for chondroprotective agents.

It is widely accepted that whilst exhibiting clinically useful anti-inflammatory and analgesic activity, the application of non-steroidal anti-inflammatory drugs (NSAIDs) does not affect the underlying pathogenesis of articular diseases such as rheumatoid arthritis. The demonstration of a role for COX-2 in the resolution of inflammation may partly underly the lack of disease modifying activity seen with NSAIDs in long term use in these inflammatory joint diseases. This has led to the suggestion that the anti-arthritic efficacy of these agents may be improved by altering prescribing practice such that they are not given during periods of disease remission, which may be difficult to achieve in the clinic. Alternatively, they may benefit from concomitant administration of chondroprotective agents, such as diacetylrhein, which may protect against the deleterious effects of traditional NSAIDs on cartilage degradation and, further, inhibit additional pathways such as cytokine elaboration which are important in joint destruction.

[Is there a future for COX-2 inhibitors?].

The two cyclooxygenase isoforms (COX-1 and COX-2--coxibs) have overlapping functions and both are involved in the regulation of homeostatic and inflammatory processes in the various tissues. Treatment with highly selective COX-2 inhibitors is associated with significantly fewer serious adverse gastrointestinal events than is treatment with the dual inhibitors--the non-selective NSAIDs. Of the two coxibs, rofecoxib was shown to be much more selective than celecoxib and with less interaction with other drugs. Various clinical studies have demonstrated that the coxibs are equivalent, in anti-inflammatory, analgesic and antipyretic efficacy to comparator non-selective NSAIDs in osteoarthritis, rheumatoid arthritis, post surgery pain and dysmenorrhea. Perioperative use of coxibs reduces pain, opioid consumption and the risk of bleeding caused by the non-selective NSAIDs. The coxibs show similar tolerability for renal, liver and cardiothrombotic events as compared to the non-selective NSAIDs. Coxibs are contraindicated in pregnancy, in nursing mothers and pediatric patients and should be used with caution in patients with asthma. The impact of the coxibs on the cardiovascular system is controversial. However, coxibs should be used in caution and at the lowest recommended dose in patients with hypertension, ischemic heart disease and heart failure. These drugs do not interfere with the aspirin anti-platelet aggregation activity. Emerging evidence suggest that the coxibs may also find potential use as supportive therapy in various malignant tumors and intestinal polyps where COX-2 is overly expressed.

[Effects of nonsteroidal anti-inflammatory drugs (NSAID) on colorectal polyps in patients with familial adenomatous polyposis: a review of clinical studies].

Experimental animal studies have demonstrated a protective effect of NSAIDs against intestinal tumorigenesis due to chemical carcinogens. Many epidemiological studies have also shown that regular aspirin use is associated with reduction of the risk of colorectal cancer. In familial adenomatous polyposis, numerous clinical studies have reported that sulindac and indomethacin are effective in reducing colorectal polyps. However, their effects are incomplete and they may cause severe toxicity. Therefore, they are unlikely to replace colectomy as primary treatment. Nevertheless, their unique effects on colorectal tumorigenesis warrant further basic and clinical research on NSAIDs, including COX-2-selective inhibitors.

The antinociceptive effect of local or systemic parecoxib combined with lidocaine/clonidine intravenous regional analgesia for complex regional pain syndrome type I in the arm.

We evaluated the efficacy of local or systemic parecoxib combined with lidocaine/clonidine IV regional analgesia in complex regional pain syndrome (CRPS) type 1 in a dominant upper limb. Thirty patients with CRPS type 1 were divided into three groups. The control group (CG) received both IV saline in the healthy limb and IV loco-regional 1 mg/kg of lidocaine + 30 mug of clonidine, diluted to a 10-mL volume with saline. The systemic parecoxib group (SPG) received a regional block similar to that administered to the CG but with systemic 20 mg of parecoxib, whereas the IV regional anesthesia with parecoxib group (IVRAPG) received an extra IV 5 mg of loco-regional parecoxib compared with the CG. The block was performed once a week for 3 consecutive weeks. Analgesia was evaluated by the 10-cm visual analog scale (VAS) and rescue analgesic consumption. The IVRAPG showed less daily ketoprofen (milligrams) consumption in the second and third weeks compared with the other groups (P < 0.05). The IVRAPG also showed less ketoprofen consumption when comparing the first and second week with the third week (P < 0.05). The VAS score comparison among groups revealed that groups were similar during the first and second week observation, although the IVRAPG showed smaller VAS scores in the third week compared with both CG and SPG (P < 0.05). We conclude the IV 5 mg of parecoxib was an effective antiinflammatory drug combined with clonidine/lidocaine loco-regional block in CRPS type 1.

Management of pelvic pain from dysmenorrhea or endometriosis.

Many women suffer from pelvic pain, and a great many visit their family doctor for diagnosis and treatment. Two common causes are primary dysmenorrhea and endometriosis. Primary dysmenorrhea is best treated by prostaglandin inhibition from nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclo-oxygenase-2 (COX-2)-specific inhibitors. Oral contraceptives can be added to improve pain control. Endometriosis can be treated with NSAIDs and COX-2-specific inhibitors as well but can also be treated with hormonal manipulation or surgery. Empiric treatment for endometriosis in selected patients is now accepted, making the disorder easier for family physicians to manage.