Keep watch on these 3 drug classes

What health plans will spend on traditional drugs is falling, caused by the wave of patent expirations for blockbuster drugs. Express Scripts, a pharmacy benefit manager, reports that spending for traditional drugs will decline through at least 2015. In its 2013 Drug Trend Report, the company expects spending to be –1 percent in 2013, –1.7 percent in 2014, and –1.4 percent in 2015. Utilization is expected to remain stable, but insurers will see even more savings as patents expire for Cymbalta (duloxetine) and Lidoderm (lidocaine).

Three traditional drug classes, however, merit watching: diabetes agents, agents that treat attention deficit disorders, and antidepressants.

The report says that for the second year in a row, medications used to treat diabetes were the most expensive therapy class per member, per year (PMPY). And while spending is expected to increase over the next few years, the magnitude of change is expected to slow. The report identifies new dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP1) competitors, and new insulins, including dulaglutide, still experimental, with once-weekly dosing that has shown promise in clinical trials, as possible new causes of spending increases.

Attention deficit disorder agents as a class had a drug expenditure increase of 14.2 percent in 2012, driven by increased utilization among adults and by shortages. That number is expected to be only 4.4 percent this year as the market stabilizes and generic competition increases. By 2014, however, expect an increase of 10 percent and then 8.6 percent in 2015. Express Scripts expects an increase in utilization among young and middle-age adults.

In contrast to these two classes, antidepressant spending should decrease. The report expects a 4.7 percent decline with the expiration of the Lexapro patent. Although there are some new drugs in the pipeline, like levomilnacipran and edivoxetine, they are expected to compete with existing drugs of the same type rather than to dramatically change utilization of existing drugs. Expect spending on antidepressants to be down 8.7 percent in 2014 and down 6.5 percent in 2015.