Merck Profit Falls, Hurt by Vioxx Recall  NEW YORK (Reuters) - Merck   Co. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MRK.N target=/stocks/quickinfo/fullquote"&gt;MRK.N&lt;/A&gt; on Thursday said  its third-quarter profit fell, hurt by negative effects of the  recall last month of its Vioxx arthritis drug.