Long-term Warfarin use may increase dementia rates in AF patients

In continuation of  Warfarin

A new study of more than 10,000 patients treated long term with the blood thinner, Warfarin, reveals higher rates of dementia for patients with atrial fibrillation versus non-AF patients.

The study by researchers at the Intermountain Medical Center Heart Institute in Salt Lake City found that atrial fibrillation patients treated long term with Warfarin had higher rates of dementia, Alzheimer's disease and vascular dementia compared to anticoagulated non-atrial fibrillation patients.

Results of the research were presented today at Heart Rhythm 2016, the Heart Rhythm Society's 37th Annual Scientific Sessions in San Francisco.

Atrial fibrillation is is the most common type of arrhythmia, which is a problem with the rate or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, or with an irregular rhythm. Incidence rates of atrial fibrillation are growing dramatically as the population ages.

Dementia is a neurological disorder that impairs memory and other cognitive abilities, and it is now listed among the leading causes of morbidity and mortality in developed countries.

Atrial fibrillation can increase the risk of dementia because it exposes patients to both large and small clots that can affect brain function. Blood thinners used to prevent all forms of clots and strokes can increase the risk of both large and small brain bleeds that can also negatively impact brain function over time.

The study was conducted through the Intermountain Healthcare Clinical Pharmacist Anticoagulation Service, which is part of the Intermountain Healthcare system based in Salt Lake City.

Researchers enrolled a total of 10,537 patients with no history of dementia prior to the study. They were treated with a blood thinner for atrial fibrillation and non-AF conditions like valvular heart disease and thromboembolism on a long-term basis.

Other variables in the patients studied included age, hypertension, diabetes, hyperlipidemia, renal failure, smoking history, prior myocardial infarction or cerebral vascular accident, and heart failure. Participants were aged 18 years and older.

Apixaban effective in polypharmacy setting

In continuation of my update on Apixaban

The superiority of apixaban over warfarin in patients with atrial fibrillation is maintained in those taking multiple medications, shows further analysis of the ARISTOTLE trial.

 Apixaban

The researchers found superior efficacy of apixaban against the primary thromboembolic endpoint (stroke or systemic embolism) regardless of the number of drugs patients were taking.

By contrast, the advantage of apixaban over warfarin in terms of major bleeding tended to decline in line with the number of drugs patients were taking. The absolute rate reduction per 100 patient-years with apixaban versus warfarin was 1.28 for patients taking up to five medications, falling to 0.82 and 0.66 for those taking six to eight and more than nine drugs, respectively.

"Importantly, the risk reduction of intracranial bleeding did not diminish with an increasing number of concomitant drugs", write the researchers in The BMJ.

"Therefore, the fact that the relative benefit of apixaban over warfarin appears to diminish across groups is due to other types of major bleeding."

They give the example of major gastrointestinal bleeding, which was significantly reduced with apixaban versus warfarin in patients taking up to five drugs, but not in those taking nine or more drugs.

Polypharmacy was common among the 18,201 ARISTOTLE participants, with 76.5% taking at least five concomitant drugs. Patients' average age rose in line with the number of drugs used, as did their stroke and bleeding risk. Patients taking more drugs also had more cardiovascular comorbidities, and also more neurological, renal, endocrine, musculoskeletal, pulmonary, gastrointestinal and haematological comorbidities.

Rates of the primary thromboembolic and bleeding endpoints rose with the number of drugs taken for patients in the apixaban group as well as those in the warfarin group.

Jeroen Jaspers Focks (Radboud University Nijmegen Medical Centre, the Netherlands) and study co-authors stress that "this increased risk of adverse outcomes should be placed in the context of the association between the number of drug treatments and comorbidities present at baseline, indicating a more frail status of patients with polypharmacy."

The researchers suggest that adjusting for these differences would abolish the relationship between the number of drugs used and safety outcomes, but add that the purpose of the study was to use polypharmacy as a marker of patient frailty.

Moreover, increasing frailty did not significantly influence the efficacy of apixaban against stroke or systemic embolism, with the relative risk versus warfarin being 14% among those taking up to five drugs and 24% in those taking more.

Study Pits New Blood Thinner Against Warfarin For Irregular Heartbeat

A new drug, Rivaroxaban, (see structure) that lowers stroke risk among people with an irregular heartbeat may give the old standby, warfarin, some competition, a new study shows.

 We know that, Rivaroxaban (BAY 59-7939) is an oral anticoagulant invented and manufactured by Bayer; in a number of countries it is marketed as Xarelto. In the United States, it is marketed by Janssen Pharmaceutica. It is the first available orally active direct factor Xa inhibitor. Rivaroxaban is well absorbed from the gut and maximum inhibition of factor Xa occurs four hours after a dose. The effects lasts 8–12 hours, but factor Xa activity does not return to normal within 24 hours so once-daily dosing is possible. Now the  new trial pitted the newer drug, rivaroxaban, against warfarin in more than 14,000 patients who were randomly assigned either warfarin or rivaroxaban. Neither the patients nor the doctors knew who was taking which drug. As per the claim by the resarchers, new agent proved to be as effective as warfarin at reducing the risk of ischemic stroke -- the most common kind of stroke,  but it did not need to be monitored as closely as warfarin since it is given as a one-size-fits-all dose....

"a reasonable alternative to warfarin, with less intracranial or fatal bleeding." claims the lead researcher, Dr. Manesh R. Patel...

Ref : http://www.newsroom.heart.org/index.php?s=43&item=1191

Dabigatran etexilate a better drug than warfarin for VTE?.

We know that Dabigatran is an anticoagulant from the class of the direct thrombin inhibitors. It is being studied for various clinical indications and may replace warfarin as the preferred anticoagulant in many cases. It is orally administered as the prodrug dabigatran etexilate (marketed as Pradaxa since April 2008 in European countries and Pradax in Canada). It was developed by the pharmaceutical company Boehringer Ingelheim.

Now researchers lead by  Dr. Sam Schulman, a professor of medicine of the Michael G. DeGroote School of Medicine (McMaster University), who conducted a randomized, double-blind trial of 2,539 patients with acute VTE (venous thromboembolism) have found that dabigatran (see structure) is a safe and effective anticoagulant that does not require the routine monitoring or dose adjustments that are necessary with warfarin. In other words, patients can receive the same results in a more convenient manner. 

As per the claim by the researchers, the improvement seen in both groups from the treatments was similar. After six months of treatment, only 2.4 percent of the dabigatran etexilate group (30 patients) and 2.1 percent of the warfarin group (27 patients) experienced recurrent VTE. The safety of the two drugs was also comparable. In the dabigatran etexilate arm, 205 patients experienced bleeding (including 20 patients with major bleeding) versus 277 patients in the warfarin arm (including 24 with major bleeding). Other possible side effects, including death, acute coronary syndromes, and abnormalities in liver function tests, were infrequent in the two groups. Hope patients suffering from VTE will now breathe a sigh of relief....

Ref : http://dailynews.mcmaster.ca/story.cfm?id=6511

FDA approves Pradaxa to prevent stroke in people with atrial fibrillation....

We knew that, Dabigatran (see structure, Pradaxa in Europe and USA, Pradax in Canada) is an anticoagulant from the class of the direct thrombin inhibitors. It is being studied for various clinical indications and in many cases it offers an alternative to warfarin as the preferred orally administered blood thinner since it does not require prothrombin time monitoring while offering similar results in terms of efficacy. It was developed by the pharmaceutical company Boehringer Ingelheim. Though it was approved in Europe in 2008, now FDA has approved the drug in October 2010 for the prevention of stroke and blood clots in patients with abnormal heart rhythm (atrial fibrillation).

Pradaxa is an anticoagulant that acts by inhibiting thrombin, an enzyme in the blood that is involved in blood clotting. The safety and efficacy of Pradaxa were studied in a clinical trial comparing Pradaxa with the anticoagulant warfarin. In the trial, patients taking Pradaxa had fewer strokes than those who took warfarin.

 "Unlike warfarin, which requires patients to undergo periodic monitoring with blood tests, such monitoring is not necessary for Pradaxa," Dr. Norman Stockbridge(director of the Division of Cardiovascular and Renal Products in the FDA's ) says.

Pradaxa, manufactured by Boehringer Ingelheim Pharmaceuticals Inc. of Ridgefield, Conn., will be available in 75 milligram and 150 milligram capsules....

Ref : http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm230241.htm

New oral blood thinners can decrease stroke risk in atrial fibrillation patients without frequent monitoring

In continuation of my update on dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis) and edoxaban (Savaysa).

A new generation of blood thinners can reduce the risk of stroke in patients with atrial fibrillation, without requiring frequent monitoring and dietary restrictions.

But special attention must be given to the patient's age, kidney function and other factors before prescribing the new medications, according to a review article by neurologists at Loyola Medicine and Loyola University Chicago Stritch School of Medicine.

The report by Rochelle Sweis, DO and José Biller, MD, is published in the journal Current Treatment Options in Cardiovascular Medicine.

Atrial fibrillation (AFib) is the most common type of irregular heartbeat, and the prevalence is increasing as the population ages. In AFib, electrical signals that regulate the heartbeat become erratic. Instead of beating regularly, the upper chambers of the heart quiver and blood doesn't flow well. Blood clots can form, migrate to the brain and cause strokes. AFib is associated with a fivefold increase in the risk of stroke.

Blood thinning medications decrease the stroke risk by approximately 70 percent. For 60 years physicians have prescribed warfarin (Coumadin) and other blood thinners known as vitamin K antagonists. These medications have been proven to be effective in reducing the risk of blood clots and strokes. But they require continual monitoring and dose adjustments to ensure the drugs thin the blood enough to prevent clots, but not enough to increase the risk of major bleeding. Patients also must restrict their consumption of foods rich in vitamin K, such as spinach, Brussels sprouts, kale, parsley and green tea.

 

Warfarin

The new blood thinners include dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis) and edoxaban (Savaysa). In the right patient population, the new drugs are a safe and effective option for treating atrial fibrillation, Drs. Sweis and Biller write.

Dabigatran         Rivaroxaban (BAY 59-7939)

Apixaban Edoxaban

New oral blood thinners can decrease stroke risk in atrial fibrillation patients without frequent monitoring: A new generation of blood thinners can reduce the risk of stroke in patients with atrial fibrillation, without requiring frequent monitoring and dietary restrictions.

Dabigatran, New Blood Thinner Linked To Higher Heart Attack Risk

In continuation of my update on Dabigatran...

Researchers lead by Dr.Ken Uchino from the Cleveland Clinic in Ohio looked at seven trials involving Pradaxa (Dabigatran) that included more than 30,000 patients. This process, called a meta-analysis, uses data from published clinical trials to tease out a pattern that might not show up in a single study. Researchers found Pradaxa was associated with an increased risk of heart attack or acute coronary syndrome (heart attack or angina), compared with two other commonly used blood thinners, warfarin (Coumadin, Jantoven) and enoxaparin (Lovenox).

As per the claim by the researchers,  those taking Pradaxa, 1.19 percent had a heart attack or suffered from acute coronary syndrome compared with 0.79 percent of those taking either of the other drugs, they noted. Although there was a 33 percent increase in relative risk for a heart attack among those taking Pradaxa, the absolute increased risk -- that is, the added risk for any one individual of having a heart attack if on Pradaxa -- was 0.27 percent, researchers said.

Pradaxa was approved by the U.S. Food and Drug Administration in October 2010 for people with a common heart rhythm problem called atrial fibrillation. People with atrial fibrillation are at a higher risk for stroke and are often prescribed medication to prevent clotting....

Ref : http://my.clevelandclinic.org/cerebrovascular_center/medical_professionals/clinical_trials.aspx

Flavonoid Compound Found in Foods and Supplements May Prevent the Formation of Blood Clots, Study Suggests...

A compound called  rutin (see structure - a quercetin derivative), commonly found in fruits and vegetables and sold over the counter a dietary supplement, has been shown to inhibit the formation of blood clots in an animal model of thrombosis.

 As per the researchers claim,

"Approximately half of all morbidity and mortality in the United States can be attributed to heart attack or stroke."..

The study focused on protein disulfide isomerase (PDI) which is found in all cells. Investigators in BIDMC's Division of Hemostasis and Thrombosis had previously shown that PDI is rapidly secreted from both platelets and endothelial cells during thrombosis, when a clot forms in a blood vessel, and that inhibition of PDI could block thrombosis in a mouse model.

"This was a transformative and unanticipated finding because it identified, for the first time, that PDI is secreted from cells in a live animal and is a potential target for preventing thrombosis," says Flaumenhaft. However, because intracellular PDI is necessary for the proper synthesis of proteins, the scientists had to identify a specific compound that could block the thrombosis-causing extracellular PDI -- without inhibiting the intracellular PDI.

They began by conducting a high-throughput screen of a wide array of compounds to identify PDI inhibitors. Among the more than 5,000 compounds that were screened, quercetin-3-rutinoside (rutin) emerged as the most potent agent. "Rutin was essentially the champion compound," says Flaumenhaft.

A bioflavonoid that is naturally found in many fruits, vegetables and teas including onions, apples and citrus fruits, rutin is also sold as an herbal supplement, having received a special designation for safety from the U.S. Food and Drug Administration (FDA). Surprisingly, studies of the rutin molecule demonstrated that the same part of the molecule that provides rutin with its ability to inhibit PDI also prevents the compound from entering cells."That finding explained how this compound can be both a potent inhibitor of PDI and a safe food supplement," says Flaumenhaft. "Our next questions were, 'Is this compound anti-thrombotic? Can it prevent blood clots?'"

New Anti-Clotting Drug May Cut Brain Bleeding Risk: Study

In continuation of my update on rivaroxaban (Xarelto)

In a new study, researchers led by Dr. Graeme Hankey, a neurologist at the Royal Perth Hospital and University of Western Australia, followed more than 14,000 people who took anti-clotting drugs for a median of two years. Of those patients, 136 had bleeding in the brain.

People who took a new anticoagulant called rivaroxaban (Xarelto) and suffered from the most common type of atrial fibrillation and didn't have heart valve damage were about one-third less likely to experience bleeding in the brain than those who took warfarin, the investigators found...

More...

CBD oil may reduce frequency and severity of seizures in patients with epilepsy, UAB study shows

Cannabidiol oil, also known as CBD oil, reduces the frequency and severity of seizures in children and adults with severe, intractable epilepsy, according to findings presented by researchers from the University of Alabama at Birmingham at the American Epilepsy Society 70th Annual Meeting.

UAB researchers presented eleven abstracts, or research findings, at the meeting. A key finding was that CBD provided a significant reduction in frequency of seizures for a majority of the patients in the study, and that approximately two-thirds of patients saw a greater than 50 percent reduction in severity.

"It is encouraging that both frequency and severity of seizures appear to improve in the majority of patients in our study, patients who have limited treatment options," said Jerzy P. Szaflarski, M.D., Ph.D., professor in the Department of Neurology and director of the UAB Epilepsy Center. "Our research adds to the evidence that CBD may reduce frequency of seizures, but we also found that it appears to decrease the severity of seizures, which is a new finding."

The results were based on an open-label study of 81 patients — 42 children and 39 adults — who experienced four or more seizures per month. UAB launched the studies of CBD oil as a treatment for severe, intractable seizures in April 2015. The studies, an adult study at UAB and a pediatric study at Children's of Alabama, were authorized by the Alabama Legislature in 2014 by legislation known as Carly's Law.

After one month of beginning CBD therapy, 68 percent of the patients had experienced a greater than 25 percent reduction in seizure frequency; 58 percent had a greater than 50 percent reduction; 36 percent had a greater than 75 percent reduction and 9 percent were seizure-free. Those results were maintained at three and six months.

To assess seizure severity, researchers led by Jenifer DeWolfe, M.D., associate professor of neurology, used the Chalfont Seizure Severity Scale, a questionnaire given prior to therapy and re-administered at intervals throughout treatment. Fifty-seven patients were followed for three months: 67 percent experienced a more than 50 percent decrease in seizure severity, while 33 percent did not. Of 47 patients followed for six months, 64 percent had a greater than 50 percent decrease in seizure severity and 36 percent did not.

"These are encouraging results, but it is important to note that each patient may respond differently to CBD, and the dose for optimal seizures control varies," said Martina Bebin, M.D., professor of neurology and co-primary investigator of the CBD studies. "There appears to be an optimal CBD dose range where the patient achieves maximum benefit. If outside this CBD dosing range, the seizure frequency may not improve and may even increase. More research is needed, including determining why and how CBD helps some people with epilepsy but not others."

Among the other UAB abstracts presented at the AES meetings:

•CBD oil was associated with an improvement in mood, an effect independent of the extent of seizure reduction. Lead author Pongkiat Kankirawatana, M.D., professor of pediatrics, says CBD oil may have overall positive effects on mood, which should be further investigated in patients with epilepsy and other chronic conditions in controlled studies.

•A study led by Szaflarski and Bebin found that the optimum dose in both children and adults was between 20 and 25 mg/kg/day.

•Jane Allendorfer, M.D., assistant professor of neurology, found that CBD, in a selected group of patients with epilepsy who experienced overall improved seizure control, has the potential for positive cognitive effects that are associated with corresponding fMRI signal changes.

•One abstract reports on an interaction between warfarin, a drug used as an anticoagulant, and CBD. This underscores the importance of monitoring appropriate laboratory work in patients receiving CBD oil along with other medications, according to study lead Brannon Vines, M.D., a clinical neurophysiology fellow.

•Significant drug interactions were identified between CBD and commonly-used medications for epilepsy, including clobazam, rufinamide, topiramiate, zonisamide and eslicarbazepine. This study, led by neurology fellow Tyler Gaston, M.D., emphasizes the importance of monitoring anti-epilepsy drug levels during treatment with CBD.

•Electrical discharges measured by EEG decreased significantly after initiation and maintenance of CBD, particularly in pediatric patients, according to a study led by Leslie Grayson, M.D., a neurology fellow.

•Using fMRI imaging, Amber Gregory, a graduate student in psychology, showed that persons with epilepsy showed gains in working memory that were associated with a shift in neural recruitment as examined with functional MRI.

•An abstract aimed at examining associations between social determinants of health, such as age, gender and socioeconomic factors against health status, quality of life and mood states showed that higher age and low income were associated with lower health ratings among epilepsy patients, according to study led Magdalena Szaflarski, Ph.D., assistant professor of sociology.

The studies are designed to test the safety and tolerability of CBD oil in patients with intractable seizures. CBD oil, a derivative of the cannabis plant, is delivered orally as an oily liquid.

The oil used in the studies is produced under stringent requirements of the United States Food and Drug Administration by a licensed pharmaceutical company. It contains only traces of THC, the psychoactive component of marijuana. The process developed by GW Pharmaceuticals guarantees the consistency of the product that is provided to study participants. 

For details read at the link