Pfizer Inc. (PFE) Chief Executive Officer Ian Read said his company, the world’s biggest drugmaker, will fight attempts to cut Medicare payments for medicines after the industry helped underwrite the U.S. health-care overhaul. Drug companies contributed $112 billion in discounts and refunds to last year’s health-care law, helping Democrats make up for new spending in the bill. U.S. drugmakers led by Pfizer and Merck & Co. are concerned they will be asked to give more in the debt-limit deal President Barack Obama signed Aug. 2 that requires further negotiated cuts in government expenditures. “We made a contribution to the Affordable Care Act that was substantial and fundamental,” New York-based Pfizer’s Read said in a telephone interview. “We are only 10 percent of the health-care spend in the United States, and we are the most efficient part of that.”