Endo Pharmaceuticals turned a first-quarter loss after absorbing a $110-million pre-tax charge connected to a settlement and license agreement with Impax Laboratories Inc.

Endo, based in Chadds Ford, Pa., said Tuesday it lost $87.3 million, or 75 cents per share, in the three months that ended March 31. That compares to earnings of $55.8 million, or 46 cents per share, in last year’s first quarter. Adjusted earnings, which do not count the charge, came in at 87 cents per share.

Revenue climbed 23 percent to $690.6 million.

Analysts surveyed by FactSet expected, on average, earnings of 87 cents per share on $700.1 million in revenue.

Endo made the Impax payment as part of the settlement of a patent dispute over generic versions of Endo’s pain drug Opana ER.

The company’s revenue jumped due in part to its $2.9-billion purchase of American Medical Systems Inc., which makes devices and treatments for use in urology and gynecology. Endo completed that deal last June.

Sales of Endo’s branded pharmaceuticals fell 3 percent in the first quarter to about $364 million. The company suspended sales of Opana ER and its joint pain treatment Voltaren Gel due to manufacturing problems at a Lincoln, Neb., factory that made the products. It recorded no sales for Voltaren Gel and $81 million in sales for Opana ER, down 4 percent from last year’s quarter.

Endo said it has since returned to a steady supply of both products and expects their sales to return to growth for the remainder of 2012.

Sales for Endo’s Lidoderm pain patch climbed 11 percent to $210 million in the quarter.

The company expects adjusted earnings of between $5 and $5.20 for the year, the same forecast it made in February. Analysts expect, on average, earnings of $5.11 per share.

Shares of Endo Pharmaceuticals Holdings Inc. fell 39 cents to $34.75 in afternoon trading, while the Nasdaq exchange climbed 1 percent.