Drugmaker Warner Chilcott PLC said Friday that its first-quarter loss widened on a surge in income taxes, but its adjusted results topped Wall Street expectations and the company boosted its 2011 outlook.

The company, based in Dublin, said it lost $24.1 million, or 10 cents per share, compared with a loss of $17.2 million, or 7 cents per share, during the same period a year prior.

Revenue fell less than 1 percent to $756.5 million.

During the quarter, a decline in sales and other costs offset a boost in restructuring and interest expenses. But, the company paid $28 million in taxes, compared with a benefit of $23.4 million a year prior. The tax costs pushed it to a loss in the most recent quarter.

The company said its adjusted cash net income, which excludes charges, was $1.04 per share. Analysts polled by FactSet expected 82 cents per share in profit on $674.9 million in revenue.

Revenue from osteoporosis drugs, which include Actonel and Atelvia, fell 11 percent to $233 million. Actonel has been losing market share to a cheaper generic version.

Sales of oral contraceptives, which include Loestrin 24 FE, rose 4 percent to $137 million. Hormone therapy revenue rose 7 percent to $49 million, while gastroenterology drug revenue rose 13 percent to $187 million.

Meanwhile, dermatology product sales fell 47 percent to $66 million and urology product sales jumped to $45 million.

Looking ahead, the company raised its 2011 financial guidance. It now expects adjusted cash net income between $3.70 and $3.80 per share from $3.60 to $3.70 per share. It also expects revenue to reach the high end of its $2.7 billion to $2.8 billion guidance.

Analysts expect $3.67 per share on $2.74 billion in revenue in 2011.