According to a new analysis released by pharmacy benefits manager Express Scripts, more than half-million Americans had medication costs in excess of $50,000 last year.

The analysis also showed that almost 90% of those ‘super spenders’ are getting specialty medications such as a highly effective treatment for hepatitis C that costs $1,000 a pill and are to be taken daily for 12 weeks.

Where on one hand the cost of some cancer treatments may not seem surprising, the emergence of high-cost hepatitis C medications is particularly notable.

ProPublica, a non-profit journalism site in March reported that Medicare has spent $4.5 billion on new hepatitis C drugs last year, and $3 billion of that on the drug Sovaldi, which runs $84,000 for a full course.

Ryan Cox, director of pharmacy services at Highmark Inc., said that specialty drugs constitute to a small percentage of prescription but they are larger and larger percentage of the total dollars spent.

He said the hepatitis C drugs are one of the primary drivers of the additional costs, while acknowledging the near-90% cure rate is extremely high for Sovaldi and the other new treatments.

It has been found that the estimated number of Americans whose medications reached $50,000 was 576,000, a 63% increase over the 352,000 for 2013.

The St. Louis-based pharmacy benefits management firm in its analysis said the number of hepatitis C patients whose drug costs exceeded $50,000 grew more than sevenfold in 2014.

They represent 39% of the estimated 139,000 Americans whose yearly medication costs reached at least $100,000, almost double the number of previous year. The report showed that over 60% of the patients were taking at least 10 different medications.

The cost to both the health plan and the patient will depend on the individual plan, the Express Scripts report said. It also said when the total reaches $100,000 the employer plan sponsor covered more than 98% of the cost, averaging $156,911 per patient.