BORDER BARGAINS

EVERY THREE MONTHS, Rose Muchway, who is sixtysomething, and her husband Earl, seventysomething, travel more than 800 miles from their home north of Eureka, California, to Los Algodones, Mexico. They go not because they are particularly fond of the tiny border town (pop. 5,000), but because Rose suffers from asthma and is dependent on inhalers that cost $83.70 each at her local pharmacy. In Los Algodones she can pick them up for $15.60.

The Muchways are far from alone. In the past few years, pharmaceutical bargain hunters have flooded across the U.S.-Mexico border. On a typical mild winter day last month,...