Antihistamines, commonly used to treat allergies, lowered the risk of hepatocellular carcinoma in people with viral hepatitis, and more frequent use was linked to greater reductions in risk, according to study results published in the Journal of Clinical Oncology.

Over years or decades, chronic hepatitis B or hepatitis C, fatty liver disease, heavy alcohol use and other causes of liver injury can lead to serious complications, including cirrhosis and hepatocellular carcinoma (HCC), the most common type of liver cancer. HCC is often detected late, and it can be difficult to treat.

Yu-Chuan Shen, MD, of Taipei Medical University in Taiwan, and colleagues conducted a study to assess whether using H1 antihistamines affects the development of HCC in people with viral hepatitis. (H1 antihistamines are used to treat allergies, while H2 antihistamines reduce stomach acid and are used to manage ulcers.)

Looking at participants in Taiwan’s National Health Insurance Research Database, the researchers analyzed data for the period from January 2006 to December 2015. The analysis included 521,071 people with hepatitis B virus (HBV), 169,159 with hepatitis C virus (HCV) and 39,016 with both HBV and HCV.

The researchers found that people with hepatitis B, hepatitis C or both who took antihistamines were much less likely to develop hepatocellular carcinoma than those who did not take antihistamines. The risk of HCC was reduced by about half in people with HBV, HCV or both viruses. What’s more, they observed a dose-response relationship in all three groups, meaning the risk fell further as the cumulative number of daily doses rose.

“The results indicated that patients with HBV, HCV, or dual virus infections who used antihistamines had an approximately twofold lower risk of HCC when compared with patients who did not use antihistamines,” wrote the researchers. “Antihistamines use is a potential adjuvant strategy for preventing HCC in patients with HBV, HCV or dual infections.”

Click here to read the study in the Journal of Clinical Oncology.

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