The global recession continued to take a toll on the drug maker Merck’s (MRK: 23.7275, -1.5425, -6.1%) business in the first months of 2009, as the company saw sales of its most popular and lucrative cholesterol and cancer drugs evaporate during the quarter. The Whitehouse Station, N.J.-based company said it earned $1.45 billion last quarter, or 67 cents a share, down 56% from $3.33 billio...