Dementia drug dosage comes under fire

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The Food and Drug Administration “breached its own regulatory standard” when it permitted a new dosage for a best-selling Alzheimer's drug, according to two professors at Dartmouth's Institute for Health Policy and Clinical Practice.

Lisa Schwartz and Steven Woloshin claim approval of 23-mg donepezil (Aricept) also conflicted with the opinions of its own reviewers, the authors write in a BMJ article. As a result, misleading consumer and physician ad campaigns have put nursing home residents and others at risk.

The authors assert that the 23-mg dose of the Eisai drug, which was approved four months before the 5- and 10-mg formulations went generic in November 2010, failed to show that it provided a significant improvement on two fronts: cognitive and global function, measures laid out by the FDA itself as the regulatory standard for approval of an Alzheimer's med. The authors say the drug had a lopsided impact, affecting only cognitive function, and did so insignificantly. They also add that the higher dose caused significant side effects.

The authors contacted the FDA about the erroneous claims made in the label, and the agency soon requested the label be changed. A new one was approved March 1, more than a year-and-a-half after the original label was posted.

According to Schwartz and Woloshin, however, Aricept 23's ability to clear the FDA was just the beginning of a disaster. Because the FDA approved a label stating that the new dose improved cognition and function, professional media ads went on to perpetuate that same language, and the drug's sales took off.

DTC ads took a soft approach to side effects. The higher dose's untoward effects are said to include a higher level of nausea and vomiting compared to the lower doses. Consumer ads brush these aside, according to the authors.
Despite these drawbacks, government and private insurance now cover the drug, and it continues to sell. Eisai said the 23-mg dose brought in $35.4 million in sales for the third quarter of fiscal 2011.