The Food and Drug Administration said Friday it was updating the labels of Merck & Co.'s (MRK) diabetes drugs Januvia and Janumet to discuss reports of acute pancreatitis seen in some patients.

The FDA said it's seen 88 reports of acute pancreatitis in patients using Januvia or Janument between October 2006 and February 2009. Of those, 58 patients had to be hospitalized and two patients had a more serious case of pancreatitis and were admitted to the intensive care unit.

The agency said 19 cases occurred within 30 days of starting treatment with either drug and that 47 of 88 cases resolved when drug treatment was stopped. The agency noted that 45 patients had at least one risk factor for developing pancreatitis such as diabetes, obesity and high cholesterol.

The agency said in a notice posted to its Web site, "FDA believes there may be an association between these events" and Januvia or Janumet.

In a statement, Merck said it conducted a safety review of clinical trials that involved more than 6,000 patients as well as post marketing reports.

"Merck believes these data do not demonstrate that a causal relationship exists between [Januvia] and pancreatitis," the company said.

John Amatruda, the diabetes franchise head for Merck Research Laboratories, said people with type 2 diabetes are more likely to develop pancreatitis than the general population.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; jennifer.corbett@dowjones.com