Drug costs and health plan claims denials are driving down branded drug sales, according to data from Wolters Kluwer Health. 

The third quarter of 2008 represented a two-year high in both areas, with 11.35% of branded drug claims denied, and 7.1% of patients never picking up their script, according to the Wolters Kluwer Health Pharma Insight survey.

In total, data found that the number of all prescriptions denied by payers increased 26% since 2006, while the number of “abandoned” prescriptions—those filled at the pharmacy but never picked up by patients—increased 34% in the same period.

Abandonment rates were much higher for pricey drugs—approaching 20% for those costing more than $30 in 2008 and increasing dramatically as co-pay amounts grew, particularly for new starts. Abandonment rates spiked in the third and fourth quarters, as Medicare Part D patients entered the coverage gap, or “donut hole,” and had to pay entirely out of pocket.

Total prescriptions in the US rose a meager 1.8% last year and the gap between generics and branded drugs widened significantly, with branded drug scripts down 12.5% and generics up 9%. The disparity was fueled by the weakening economy and the impact of Medicare Part D, which has meant a much bigger say for managed care companies and prompted patients to drop therapies as they fall into the “donut hole.”

“It’s important to understand to what extent your product does or does not fall disproportionately into Medicare Part D,” said David Martin, vice president of sales and marketing, pharma solutions, at Wolters Kluwer Health, noting that self-dealing laws prevent pharmas from paying a patient’s Medicare Part D co-pay.  Addressing generic use among patients requires an understanding of the degree to which influence is exerted by the payer, said Martin. “Make sure patient education programs build the case that your medicine is a core treatment [in a patient’s total drug regimen],” said Martin.