NEW YORK -- Drug maker Pfizer says its first-quarter profit fell 18 percent on lower sales of blood-pressure drug Norvasc and the allergy drug Zyrtec, but topped Wall Street forecasts after excluding acquisition charges.

The New York-based company earned $2.78 billion, or 41 cents per share, compared with profit of $3.39 billion, or 48 cents per share, during the same period a year ago. Pfizer earned 61 cents per share, excluding charges for the buyouts of CovX and Coley Pharmaceutical Group Inc.

Revenue fell 5 percent to $11.85 billion from $12.47 billion.

Analysts polled by Thomson Financial expected profit of 66 cents per share on revenue of $12.09 billion.

Norvasc lost patent protection in March of 2007 and Pfizer stopped selling Zyrtec in January.