Pfizer Inc. posted a 25 percent jump in second-quarter net income Tuesday due to aggressive cost cutting and lower restructuring and other charges, shaking off the expected plunge in revenue from generic competition to cholesterol fighter Lipitor, the world’s top-selling drug ever.

The world’s biggest drug maker easily beat analyst expectations. Pfizer’s stock rose 51 cents, or 2.2 percent, to $24.22 in afternoon trading. That’s a new 52-week high but still far below the stock’s $48 peak 12 years ago.

The maker of Viagra and painkiller Celebrex, based in New York, said net income was $3.25 billion, or 43 cents per share, up from $2.61 billion, or 33 cents per share.

Excluding $2.1 billion in charges before taxes, adjusted net income was $4.67 billion, or 62 cents per share — 8 cents more than Wall Street expected. Charges included $1.2 billion for asset writedowns and $474 million in legal charges, mainly for litigation over its hormone replacement medicines.

Revenue totaled $15.06 billion, down 9 percent but above expectations of $14.93 billion.

Analyst Dr. Timothy Anderson of BernsteinResearch wrote to investors that Pfizer’s strong profit was primarily driven by better revenue, better gross margins, and lower selling, general and administrative spending. Pfizer has reduced its workforce from about 110,600 people at the end of 2010 to 101,000.

Generic competition reduced sales by about $1.8 billion, mainly because Lipitor, which had peak annual global sales of $13 billion, got U.S. generic rivals on Nov. 30. Early sales losses to two generic versions were slowed by Pfizer’s unprecedented strategy to keep patients on its brand as long as possible.

Prescription plans got huge rebates to exclusively cover Lipitor and patients got discount cards to buy the pills for a $4 monthly copayment. The insurer rebates stopped on May 30, when several more generic versions flooded the market. Prices plunged from about $175 a month for Lipitor to around $15 for generics.

During the quarter, U.S. Lipitor sales nosedived to $296 million from $1.4 billion a year ago; global sales slumped 53 percent, to $1.22 billion.

Still, “We kept three times more (market) share than has traditionally occurred” after a big drug’s patent expired, CEO Ian Read said in an interview. “We added hundreds of millions of dollars of profitability to the company, as well as enabling patients to stay on the brand.”

Newer drugs, particularly pain reliever Lyrica and Prevnar 13, a vaccine against ear infections, meningitis and other bacterial diseases, saw sales jump just over 10 percent. Lyrica sales hit $1.04 billion and Prevnar 13 totaled $916 million.

Total pharmaceutical sales fell 10 percent, to $13.14 billion. Sales of veterinary medicines edged up 3 percent to $1.09 billion. Sales of consumer health care products, such as ChapStick and Centrum vitamins, increased 8 percent to $768 million.

Pfizer said it expects action from the Food and Drug Administration soon on two experimental drugs that have run into trouble.

In early August, Pfizer will submit a new analysis the FDA requested of testing data on tofacitinib, for rheumatoid arthritis. That should push back the agency’s Aug. 21 target date for an approval decision. On Tuesday, the company said initial results of a new study showed tofacitinib was better than the standard treatment at reducing symptoms and limiting structural damage from the immune disorder.

The FDA also has requested more information on “data management and verification” from a huge international study that examined how well blood thinner Eliquis prevented strokes in patients with an irregular heartbeat called atrial fibrillation.

Analyst Erik Gordon, a professor at the University of Michigan’s Ross School of Business, questioned what the impact will be from Pfizer’s cost-cutting in research, sales force and administrative spending, and “whether Pfizer can move out of shrink-the-company mode and back to growth mode.” That depends on the success of its late-stage drug candidates and ability to grow foreign sales, he said.

Overall, Pfizer said U.S. revenue fell 15 percent to $5.7 billion. International revenue declined 5 percent to $9.3 billion.

Pfizer maintained its 2012 forecast for adjusted earnings per share of $2.14 to $2.24 and revenue of $58 billion to $60 billion.