ST. LOUIS (AP) — Prescription drug spending growth last year mirrored 2011's increase, but U.S. spending on traditional medicines for problems like high cholesterol fell for the first time in more than 20 years, according Express Scripts Holding Co.'s annual drug trend report.

Total spending grew 2.7 percent last year, as an 18.4 percent increase in specialty medication spending countered a 1.5 percent decrease for those traditional drugs. Specialty drugs often require frequent dosing adjustments, more intensive clinical monitoring and specialized handling or administration. They can include treatments for multiple sclerosis and cancer.

They also include hepatitis C drugs, where two new treatments helped spending in that therapy class climb nearly 34 percent, said Express Scripts, the nation's largest pharmacy benefits manager.

An increase in cheaper generic equivalents to drugs like the cholesterol fighter Lipitor contributed to the spending decrease for traditional treatments. Generics have chipped away at revenue for drugstores and pharmacy benefits managers for several quarters since U.S. patents protecting the drugs expired.

Express Scripts, based in St. Louis, said the country spent more on diabetes drugs than any other therapy class for the second year in a row. Spending on attention disorder treatments also increased more than 14 percent.

Express Scripts compiled its annual drug trend report using data culled from its business, which manages 1.4 billion prescriptions each year.

Pharmacy benefits managers, or PBMs, run prescription drug plans for employers, insurers and other customers. They process mail-order prescriptions and handle bills for prescriptions filled at retail pharmacies.

Shares of Express Scripts rose 6 cents to $57.94 Tuesday morning trading as the broader continued its rally.