Like with the case of Vioxx, some patients are willing to take the risk of serious side effects:

Michael Barron, a 48-year-old former operator of a nuclear power plant, was so crippled by relapses in his multiple sclerosis that he couldn’t stand up without help. The drug Tysabri allowed him to take walks with his wife again.

Then a year ago, Biogen Idec Inc. and partner Elan Corp. suspended sales of Tysabri after just three months on the market because of a link to a fatal brain infection. Barron will travel across the U.S. next week from his home in Arizona to join other patients demanding that federal regulators allow sales to resume and let patients choose whether to risk the side effects.