Cylert® (pemoline) Linked to Liver Failure
ADHD Medication, Cylert®, Taken Off the Market
ABBOTT PARK, IL — June 24, 2005 — Abbott Laboratories is taking Cylert® (pemoline) off the market “based on declining sales,” according to a letter the company sent to doctors last month. One can only wonder whether the real reason for the decision is bad publicity about Cylert®’s link to liver problems. Prescribing information, enclosed with the letter, reveals that Cylert® can cause “life threatening hepatic [liver] failure” and “should not ordinarily be considered as first line drug therapy.”
Cylert® was approved in 1975 for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in children. Used to increase attention and decrease overactive behavior, Cylert® is in the class of medications called central nervous system stimulants. Other related drugs in this category, also used to treat ADHD, include Dexedrine® (dextroamphetamine) and Ritalin® (methylphenidate).
Cylert® users have reported 15 cases of liver failure to the Food and Drug Administration (FDA) since 1998, according to Abbott. Twelve of these cases resulted in liver transplants or death. Although the total number of cases of liver failure is small, most medical experts believe that adverse drug reactions are vastly under–reported. An FDA analyst, Dr. David Graham, estimates a 16.8–fold increased risk of acute liver failure in patients taking Cylert® compared to the general population (Press Release, Public Citizen, March 24, 2005; CDER, Cylert® Approval Package, Fulminant Hepatic Failure with Pemoline, FDA Memorandum from Medical Officer, April 17, 1996).
The consumer group, Public Citizen, noted 21 cases of liver failure from Cylert® since the drug was marketed in 1975. The group also points out that reports of liver problems appeared in clinical trials even before Cylert® was approved. Between the 1975 approval and 1996, there were 193 adverse drug reactions involving the liver, according to Public Citizen, which unsuccessfully petitioned the FDA in March of this year to ban the drug.
Cylert® Label Warnings Were Not Always Heeded
Before approving Cylert®, the FDA expressed concern about the rate of liver failures caused by the drug. As a condition for approval and continued sales, Abbott was required to establish a national registry for reporting adverse reactions from Cylert® (CDER, Cylert® Approval Package). To date, Abbott has not created such a registry.
In 1996, the FDA required Abbott to modify the Cylert® label to indicate that patients should try other types of ADHD drugs before they were given Cylert®. Because of the risk of liver toxicity, the new label instructions said, Cylert® should be used only as a second–line therapy. In June, 1999, the label was again revised to require that the patient’s liver enzymes be checked every two weeks. Both changes were included in a prominent, bolded black box, the highest caution level for a drug that is still on the market.
An FDA study showed, however, that compliance with the Cylert® warnings was low (J Am Acad Child Adolesc Psychiatry. 2002 Jul; 41(7): 785–90). The report looked at 688 patient claims in a health care database between January 1998 and March 2000. It found that only 237 patients (34%) had received another drug for ADHD before taking Cylert®. The researchers also divided the data into two six–month periods before and after the June 1999 labeling change that required doctors to monitor the patient’s liver enzymes. Prior to the label change, only 12% of Cylert® users were given baseline liver enzyme tests; after that date, only 11% were given these tests. Doctors performed follow–up liver enzyme tests in only 9% of patients during the pre–label change period. Only 12% of patients in the post–label change group had these tests.
Cylert® Withdrawn in UK and Canada
The United Kingdom banned Cylert® in 1997, and Canada removed it from the market two years later. In the United States, Abbott will allow Cylert® to remain on pharmacy shelves until supplies are exhausted. Although Cylert® will no longer be available in the country at that time, the generic form of the drug, pemoline, may still be legally marketed by other companies.
Injuries from Unsafe Medications
Brayton Purcell is committed to helping people who have been injured by unsafe medicines. We will keep you up–to–date on any further efforts to ban pemoline. Meanwhile, please feel free to contact us if you would like more information about medical drug injuries and your legal choices. We have been handling medically–related consumer cases for over 20 years, and work hard to defend the legal rights of our clients.
