Question: After statins had been in use for several years, data began to accumulate purporting to show that they increase the risk of diabetes. When Mrs. Smith learned that her recent diagnosis of diabetes might have something to do with the drug, she consulted a lawyer who began advertising for similar cases to consolidate them into a class action lawsuit. The legal theory (theories) seeking to prove product liability will be based on:
A. Contract law and breach of warranty.
B. Negligence in tort law.
C. Strict liability without requiring proof of fault.
D. A defective product that is unreasonably dangerous.
E. All of the above.
Answer: E. Should a prescription drug lead to harm, an injured party can sue the manufacturer who had placed it into the stream of commerce. The law of products liability governs this cause of action, wherein recovery is based on a number of legal theories, specifically negligence, breach of warranty, and strict liability. The latter is the most favored, as there is no need to prove fault or warranty. Products liability law also covers defective medical devices. The recent multimillion-dollar settlements and jury verdicts with Endo, Johnson & Johnson, Bard, and other manufacturers over their vaginal mesh devices are good examples.
In products liability, injured plaintiffs frequently claim a failure to warn of known risks, such as cardiovascular deaths caused by Vioxx, a nonsteroidal anti-inflammatory drug that was withdrawn in 2004. Merck, its manufacturer, has thus far won 11 and lost 3 of the cases that have gone to trial. Some of these judgments are under appeal; most notably, a Texas Court of Appeals recently reversed a $253 million award initially won by plaintiff Robert Ernst in the very first trial. However, the company has proposed $4.85 billion to settle tens of thousands of similar pending lawsuits. Other recent examples alleging failure to warn are heart attacks linked to the diabetes drug rosiglitazone and bladder cancer associated with the diabetes drug pioglitazone.
In 1963, the California Supreme Court bypassed the law of contracts and warranty in a seminal case of product-related injury, and introduced the notion of strict liability, which goes beyond simple negligence ( Greenman v Yuba Power Products Inc. , 377 P.2d 897 [Cal. 1963]). The strict liability approach centers on whether a product is defective and unreasonably dangerous, and it has now been adopted in virtually all jurisdictions.
The theory holds that a professional supplier who sells a product that is both defective and unreasonably dangerous is strictly liable to foreseeable plaintiffs. “Defective” is usually defined as product quality that is less than what a reasonable consumer expects. “Unreasonably dangerous” is a conclusion that the risks that result from its condition outweigh the product’s advantages.
Strict liability is not about negligence or fault, but about a social policy that shifts to the manufacturer the cost of compensating the injured consumer. To prevail, the plaintiff must show proximate cause, and assumption of risk is still a valid defense.
Statins, which are powerful HMG-CoA reductase inhibitors widely used to treat hypercholesterolemia, are currently at the center of pharmaceutical products litigation.
Pfizer, the manufacturer of Lipitor (atorvastatin) has become the target of numerous lawsuits alleging that the drug causes diabetes. Lipitor is the best-selling prescription drug ever, with sales reaching $130 billion since it was approved in 1996. In the United States alone, more than 29 million people have been prescribed this medication. The drug is highly effective in lowering serum cholesterol and is proven to reduce cardiovascular deaths.
A meta-analysis in 2010 revealed an increased risk of diabetes in patients taking statins ( Lancet 2010;375:735-42 ). Statin therapy was associated with a 9% increased risk for incident diabetes; it was calculated that treatment of 255 patients with statins for 4 years resulted in 1 extra case of diabetes. An earlier smaller study had rejected this conclusion, but other studies were in support.
In 2012, the Food and Drug Administration (FDA) required the revision of the package insert of Lipitor and other statins to warn that their use had been linked to a small increased risk of diabetes.
In 2013, a large Canadian study confirmed the increased incidence of new-onset diabetes in patients taking atorvastatin (hazard ratio, 1.22) and simvastatin (hazard ratio, 1.10). This population-based cohort study involved nondiabetic patients age 66 years or older who started statins between 1997 and 2010 ( BMJ 2013;346:f2610 ).
These and other results, coupled with the FDA-mandated revised labeling, have spawned the filing of nearly 1,000 lawsuits by patients who developed diabetes while taking statins, especially postmenopausal women. The rapid increase in the number of lawsuits may be related to the recent decision of a federal judicial panel on multidistrict litigation to consolidate all Lipitor diabetes lawsuits into a single federal courtroom in Charleston, S.C., as a class-action suit. The first case has yet to go to trial, but is expected to do so in 2015.
Previous products liability cases implicating statins have famously involved cerivastatin (Baycol), a one-time rival to Lipitor, for causing rhabdomyolysis. The drug was pulled from the market in 2001 after it reportedly caused 31 deaths. Bayer, its manufacturer, paid about $1 billion in 2005 to settle some 3,000 cases. An example of a medication causing diabetes is quetiapine (Seroquel), an antipsychotic drug manufactured by AstraZeneca, which in 2011 agreed to pay $647 million to settle more than 28,000 lawsuits.
However, the upcoming Lipitor litigation may be more difficult for the plaintiffs to win. Among some of the medico-legal questions to be addressed are:
1) Was there prior company knowledge of the risk and a failure to warn?
2) Were the patients harmed by the drug, given that diabetes is a very common disease and may be linked more to genetics and/or an underlying metabolic syndrome in those who are hyperlipidemic, hypertensive, or obese – the very same patients likely to be on a statin?
3) Is Lipitor a defective product, and is it unreasonably dangerous?
Despite the FDA-directed change in labeling, a number of scientists and the FDA itself have emphasized that the cardiac benefits of a statin drug are greater than any small increased risk of developing diabetes.
Dr. Tan is professor emeritus of medicine and former adjunct professor of law at the University of Hawaii, and currently directs the St. Francis International Center for Healthcare Ethics in Honolulu. This article is meant to be educational and does not constitute medical, ethical, or legal advice. Some of the articles in this series are adapted from the author’s 2006 book, “Medical Malpractice: Understanding the Law, Managing the Risk,” and his 2012 Halsbury treatise, “Medical Negligence and Professional Misconduct.” For additional information, readers may contact the author at siang@hawaii.edu.
