TRENTON, N.J. (AP) — Schering-Plough Corp. says sales of the cholesterol drugs it markets with partner Merck & Co. have started dropping again. Schering-Plough says in a Securities and Exchange Commission filing that sales of Zetia were down almost 9 percent from October to November. Sales of Vytorin, which combines Zetia and Merck’s older, now-generic cholesterol drug Zocor, are down 10 percent.
