Coumadin Side Effects Lawsuit Information


Anticoagulant Coumadin, introduced six decades ago, continues to be one of the most reported prescription drug for side effect injuries, according to the latest annual data released by the Institute for Safe Medication Practices. With at least 490 direct side effect injury complaints filed on the MedWatch adverse event system by consumers and healthcare professionals in 2011, the Warfarin-based blood thinner ranks second to Pradaxa as the most dangerous drugs reported to the FDA.


Manufacturer Bristol-Myers Squibb also found more than 600 instances of Coumadin side effect injuries during post-marketing surveys carried out in 2011, says the annual QuarterWatch surveillance report. Coumadin has been widely linked to major side effects resulting in hemorrhage, Warfarin necrosis leading to gangrene of skin and limbs, bone decay and osteoporosis, purple toe syndrome, and food poisoning.


History of Coumadin


                                            Coumadin Fact File

Generic Name: Warfarin Sodium

Coumadin Use: Anticoagulant, blood thinner;

Manufacturer:  Bristol-Myers Squibb, NYC, USA

Year of Approval:  1954

MedWatch Complaints: 490 directly from consumers and doctors and 616 from manufacturers

Major Coumadin Side Effects: Hemorrhage, Warfarin necrosis, osteoporosis, purple toe syndrome

Coumadin Warning: FDA black box warning in October 2006; safety warnings in 2006, 2007, 2010, 2011

Coumadin Lawsuits: Hundreds of  product liability lawsuits filed in the US courts; in 2007, a  Coumadin lawsuit led to $25 million award

Coumadin Recalls:  July 2010 and May 2011 citing the risk of overdose




In 1954, the FDA permitted Bristol-Myers Squibb to introduce blood thinner Coumadin containing Warfarin sodium. The anticoagulant is widely prescribed by doctors to treat blood clotting in veins and arteries. People who have undergone heart-valve replacement, knee and hip operations or irregular heartbeat face the risk of thrombosis in lungs, legs, or other body parts. Coumadin is given to such people to lower any future risk of blood clot that may result in heart attacks and strokes.


The blood thinner inhibits vitamin K in the body prohibiting synthesis of clotting factors that derive strength from it. This stops blood from coagulating and prevents formation of dangerous blood clots and embolisms in users. Coumadin ranked among the top 10 most reported drugs for adverse events on the FDA MedWatch program during the 1990s and 2000s. It accounted for the highest number of prescription drug deaths in 2003 and 2004. More than 30,000 consumers suffered from serious bleeding complications caused by Warfarin every year.


Coumadin received FDA black box warning in 2006, citing the risk of fatal internal bleeding. The federal regulator went on adding more safety measures through Warfarin label changes in 2007, 2010, and 2011. Manufacturer Bristol-Myers Squibb was forced to issue two successive recalls in 2010 and 2011 anticipating higher doses in oral pills that could put users at the risk of deadly hemorrhage.


Coumadin Side Effects



  • Hemorrhage: Lack of blood clotting results in heavy and fatal internal bleeding in users. Coumadin has been linked to gastrointestinal, intracranial, spinal cord, and intra-abdominal hemorrhages that may result in the death of users or even lead to disability. It is also found to cause chest pain, muscle pain, paralysis, coughing up blood, and hypotension due to resultant bleeding complications. Senior citizens face a far greater risk of hemorrhage due to the age factor.

  • Warfarin Necrosis: Many treated with Coumadin have experienced Warfarin-induced skin necrosis within 10 to 15 days of taking the drug. Coumadin users develop lesions or hemorrhagic blisters in breasts, thighs, eyelids, and buttocks that gradually become necrosis.

  • Osteoporosis:  Three studies published between 1999 and 2006 highlighted that lack of Vitamin K synthesis in the body caused by Warfarin could lead to reduced bone mineral density. This makes Coumadin users prone to the risk of osteoporosis.

  • Purple Toe Syndrome: Decreased blood clotting caused by Warfarin may lead to cholesterol embolism in different parts of the body that obstructs normal blood flow. It results in skin problems, gangrene of limbs, and also renal failure.

  • Food Interactions: Coumadin taken with herbs, spices, certain juices, fruits, fish oil, and protein rich food may result in neurological problems, including depression, internal bleeding, and less anticoagulant effect.

  • Dermatologic Side Effects: Warfarin can cause skin rash, urticaria, alopecia, and pruritus in users.


  • Cardiovascular Disorders: Coumadin side effects may result in cholesterol microemboli, hypertension, chest pain, vascular compromise, angina syndrome, and cardiac tamponade.

  • Renal Problems: The drug can lead to cholesterol microemboli, which, in turn, results in renal impairment and interstitial nephritis.

  • Hepatic Side Effects: Coumadin causes cholestasis, jaundice, and hepatitis.

  • Other Warfarin Side Effects



  • Gastrointestinal: Flatulence, abdominal pain, vomiting, and nausea

  • Genitourinary: Priapism and sex organ skin necrosis

  • Nervous system: Depression, taste change, fatigue, fever and chills, headache, and dizziness

  • Ocular: Retinal hemorrhage



Coumadin Warnings


FDA Warning and Recalls


  • In October 2006, the FDA mandated black box warning on Coumadin cautioning consumers and healthcare professionals about potential risk of fatal bleeding.

  • In January 2007, the FDA revised the safety labeling on the drug and advise on individualization of dosage to prevent any adverse hemorrhage.

  • In January 2010, the labels are further changes to include close monitoring of PT/INR of individual consumers treated with Warfarin blood thinner.

  • In July 2010, the federal regulator asked the manufacturer to withdraw three lots of Coumadin following discovery of poor quality isopropanol in these tablets.

  • In April 2011, the FDA forced another recall of Coumadin tablets citing potential defects and extra strength that could jeopardize lives of consumers treated with the blood thinner.


Research Studies


  • In 2001, the Sixth American College of Chest Physicians classified internal bleeding instances caused by Coumadin and other Warfarin anticoagulants as major and fatal injuries.

  • In 2002, a review study reported that 16 percent users treated with Coumadin and other Warfarin blood thinners are likely to suffer from major hemorrhage while 3 percent face the risk of fatal bleeding.  

  • The UK Committee on Safety of Medicines received reports of several Warfarin-induced hemorrhage incidents in 2003 and 2004 among Coumadin users.

  • A study by Washington University School of Medicine reported in January 2006 about the high risk of bone fractures in elderly consumers taking Coumadin. The research article published on the Archives of Internal Medicine highlighted the risk of Coumadin-induced osteoporosis.

  • The Canadian Medical Association Journal published a study in August 2007 that established clear link between Coumadin and enhanced risk of gastrointestinal bleeding.

  • In November 2011, the New England Journal of Medicine published an analysis that claimed 33 percent of all elders hospitalized every year because of Coumadin and other Warfarin-based drug side effect injuries.


Coumadin Lawsuits

Hundreds of people affected by Coumadin side effect injuries have filed product liability lawsuits against Bristol-Myers Squibb in various US courts. The plaints have claimed that the manufacturer failed to adequately disclose about the potential Coumadin side effects over the years. A number of lawsuits have also been filed against hospitals and nursing home for their failure to treat patients suffering from Coumadin side effect injuries.


In 2007, a Florida jury ordered Walgreens pharmacy to pay $25.8 million to the family of a woman who died following erroneous prescription of Coumadin. The victim was given 10-time stronger Coumadin dosing than required. In October 2008, a Franklin County court approved $80,000 claim put forward by the family of a man who died after administered Coumadin. The nursing home and its staff were held guilty for failing to monitor blood INR of the patient.