We live in a culture that venerates the new: new fashions, new cars, new moviesand new "miracle" drugs. But like new cars that exhibit glitches leading to recalls, new drugs may have unexpected side effects.
Consider the now infamous diet-drug combination fen-phen (fenfluramine and phentermine). The drugs themselves were not new, but the combination was hailed as a "breakthrough" in 1992 when doctors began prescribing it regularly. After more than 6 million prescriptions had been written, the duo was found to cause heart valve damage.
Before gaining approval, new drugs must be tested in both lab animals and humans. But those tests often create little more than the illusion of safety. The FDA may approve a new drug based on studies that show benefits without significant side effects in 2,000 rats and 200 humans. But the drug may cause serious problems in one of every 5,000 users. It would take several years for enough people to experience the problem and to connect it to the drug. A General Accounting Office review of 198 of the 209 new drugs approved from 1976 to 1985 found that 52 percent had "serious postapproval risks."
Of course, if you have a life-threatening illness, the benefits of new drugs outweigh the risks. But for less grave conditions, think twice before taking new drugs.M.C.