Insurers are beginning to experience hepatitis-C-induced anxiety over Sovaldi. Forbes’s Matthew Herper cites analyst research that indicates the high-priced drug could inflict earnings-per-share damage on payers of “as much as 10%.”

While Herper notes that analysts such as ISI Group’s Mark Schoenebaum make the point that the virus-clearing drug may be cost-effective because it bypasses the high price of liver failure, Sovaldi’s effectiveness and popularity could tax health systems more than anticipated because “insurers are always going to worry about patients coming out of the woodwork.”

Herper’s example: heartburn, “which was treated far less often before AstraZeneca launched Prilosec, which was very effective and became the best-selling drug in the world.”

Lawmakers and others have attacked the drug’s high price, around $84,000 for 12 weeks of treatment. Earlier regimens, such as direct-acting antiviral treatments like Merck’s Victrelis and Vertex’s Incivek, cost between $80,000 and $100,000 for the duration of treatment.