An even if a drug is essentially “safe,” there can still be pretty unpleasant side effects associated with taking it, including nausea, headaches, hair loss and skin irritation. Some drugs, like Merck’s Vioxx, may even squeeze through clinical trials despite evidence of more serious “side effects.” (Vioxx, which was sold to an estimated 20 million Americans before being withdrawn from the market, has been shown to cause heart attacks.)
Clinical trials are also complicated by the fact that drug safety is rarely a black-and-white issue. Safety and efficacy are often highly dependent on dosage, and it’s difficult to predict the correct dosage from preclinical tests. As a result, trials are often used to experiment with dosage, and even if a drug is safe in certain amounts, it’s possible for volunteers to be administered an incorrect and harmful amount. Although overdose risk is minimized by giving volunteers low doses to start with and gradually increasing them, dosage effects are not always predictable.
That said, drug companies try their best to ensure that drugs entering clinical trials are likely to be safe. A clinical trial is an expensive venture, so it’s in a company’s best interest to uncover potential safety issues before a trial begins. To this end, companies are constantly developing technologies and improving animal tests so as to weed out dangerous or useless drugs early on.
Comment & Debate