Cheap allergy drug may be effective for hepatitis C

Preliminary lab research suggests a hay fever drug that costs about 50 cents a pill has the potential to treat hepatitis C, a stubborn disease that has spawned drugs that sell for $1,000 a dose.

It's too early to know if the antihistamine chlorcyclizine HCI will work in people as a treatment for hepatitis C. Still, the new research suggests that "the drug blocks the virus getting into cells and is different from the current hepatitis C drugs, which block viral replication," said study co-author Dr. T. Jake Liang, a senior investigator with the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.

Moreover, "this drug complements the existing hepatitis C drugs and can be used in combination with them," Liang added.

Hepatitis C often leads to serious liver complications such as cirrhosis. Some expensive new medications are "astonishingly effective" with cure rates of more than 90 percent, said Dr. Douglas Dieterich, a professor of liver diseases at Icahn School of Medicine at Mount Sinai in New York City.

But the pills are more than $1,000 each and need to be taken for weeks, potentially costing $84,000 to $93,000, a recent analysis found. While more drugs are in the pipeline, Dieterich said they're likely to be just as pricey.

About 3.2 million Americans have hepatitis C, according to the U.S. Centers for Disease Control and Prevention. One recent study put the cost of getting the new drugs to patients at $65 billion over just five years.

For now, "only those with more advanced liver disease are obtaining access, due to high drug costs and restrictive policies of many public and private insurance carriers," said Dr. Joseph Lim, director of the viral hepatitis program at Yale University School of Medicine in New Haven, Conn.

Liang and his team have tried to determine if new uses of existing drugs might work to treat the disease. In this study, they grafted human liver cells into mice to test the allergy drug.

An over-the-counter antihistamine, chlorcyclizine HCl costs $16.98 for 30 pills when sold under the brand name Ahist.

Chlorcyclizine has been around for decades but is not widely used. But the researchers found that the drug appears to prevent an early stage of infection with hepatitis C.

The drug could be used in all kinds of hepatitis C patients, Liang said, and could help prevent re-infection in patients who undergo liver transplantation.

The research is early, and a number of challenges remain, however. For one thing, "we would have to use the currently accepted dosing for any clinical trial, because the drug at high doses may have significant side effects, such as drowsiness," Liang said. "It is possible that the current dosing may not be active against hepatitis C in people."

In addition, he said, scientists might have to modify the drug to minimize its antihistamine effect. "This effort will require additional pharmacological research and development," Liang said. Drowsiness and dry mouth are common side effects of older hay fever drugs.

Dieterich praised the study and said it offers hope that "there may be very cheap and available drugs" to treat hepatitis C.

But Lim said other drugs in development could succeed in driving down prices once they're released, raising the question about whether a medication like this one will be needed.

What's next? "Currently, we are trying to optimize this class of drugs in the laboratory and hopefully [test it] in people in the near future," Liang said.

The study appears in the April 8 issue of Science Translational Medicine.