Given the task definition and input, reply with output. Given a paragraph, generate a claim that is supported by the given paragraph. 1) The claim must contain information from within the paragraph. 2) A sentence within the paragraph can be used as a claim. 3) The claim should not have contradictions within the paragraph. 4) The claim should be at most one sentence long.

The letter, sent by J&J's Tibotec Therapeutics unit to doctors this month, cited cases of drug-induced hepatitis as well as liver injury and death. "We are issuing a new warning on our labeling," Tibotec Therapeutics spokeswoman Pam Van Houten told Reuters. The company said in its letter that the problems have not been linked directly to Prezista, a once-daily protease inhibitor that was given in combination with the drug ritonavir. Ritonavir is sold by Abbott Laboratories under the name Norvir. Fifteen cases of liver problems were reported during clinical trials, Van Houten said. She added the company did not provide information on post-marketing cases reported after the drug's U.S. approval in 2006. Most of the cases occurred in patients with advanced HIV, who were taking multiple medications, as well as those who were also infected with hepatitis B or C, the letter said. The letter and Van Houten did not say how many liver-related deaths occurred. The FDA warning was released on its Web site here
J&J, FDA warn of liver risk with HIV drug patients.