EXTON, Pa. (AP) — ViroPharma Inc. reported a second-quarter loss as generic competition for the antibiotic Vancocin hurt the drugmaker’s revenue, which tumbled 26 percent.

The Exton, Pa., company said Thursday that Vancocin revenue sank to $15.9 million from $65.2 million because of the introduction of generic vancomycin capsules. Branded drug sales typically drop after a competitor introduces cheaper generic products.