AstraZeneca Sues U.S. Generic Drug Maker  NEW YORK (Reuters) - Drug maker AstraZeneca Plc  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AZN.L target=/stocks/quickinfo/fullquote"&gt;AZN.L&lt;/A&gt;&lt;AZN.N&gt; on Thursday said it has sued generic drug maker  KV Pharmaceutical Co &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=KVa.N target=/stocks/quickinfo/fullquote"&gt;KVa.N&lt;/A&gt; over one of its branded high blood  pressure medications.