With Claritin 's decline , Schering-Plough 's best-selling product them now are two drug them used together to treat hepatitis C , the antiviral pill ribavirin and an interferon medicine called Peg-Intron .
With Claritin 's decline , Schering-Plough 's best-selling product them are now antiviral drug ribavirin and an interferon medicine called Peg-Intron -- two drug them used together to treat hepatitis C.