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