The One-Size Dose Does Not Fit All: Physicians and Patients Should Look beyond the Guidelines Recommended by Drug Manufacturers
When I began prescribing Prozac 10 years ago, I found that about half my patients responded well while the other half didn't. One woman became psychotic within five days. Another developed panic attacks so severe she couldn't work. Though I'd given them the lowest recommended dose--20mg a day--it was simply more than they could tolerate. Then, in the medical library, I found a study that shocked me. It showed that even before the Food and Drug Administration approved Prozac, testing had shown that 54 percent of depressed patients required only 5mg. No wonder so many of my patients reacted badly. They were getting four times the medication they needed.
It's clear to me that the cookbook approach to prescriptions defies both medical science and common sense. People respond very differently to medications depending on weight, age and inborn ability to process drugs, just as they differ in their capacities for coffee or alcohol. That's why some patients require 80mg of Prozac a day while others need as little as 2.5mg. But our standard methods of prescribing drugs ignore this variation. Although 45 percent of women can relieve menstrual pain with 200mg of nonprescription Motrin, doctors usually prescribe 400mg. The starting doses that doctors obtain from the Physicians' Desk Reference (PDR) for many blood-pressure drugs (Norvasc, Vasotec, Zestril, Prinivil) are equally inflated. And though a given dose of many drugs will yield higher concentrations in the blood of an elderly person than in a younger adult, seniors get the same doses of Lipitor (for high cholesterol), Allegra (for allergies), Celebrex (for arthritis) and many other drugs. Perhaps this is why more than 50 percent of people taking medication for high cholesterol and high blood pressure quit their medications within one year.
The consequences for patients can be serious. Medication reactions are now a leading cause of death in the United States, ahead of AIDS, accidents and infectious diseases. There are more than 2 million severe adverse drug reactions and 106,000 medication-related fatalities in U.S. hospitals every year. Most of the adverse reactions occur at the very doses that manufacturers recommend and doctors prescribe. But these are not unforeseeable hazards. The clinical trials that manufacturers perform to test new drugs are often too small or too brief to identify the lowest effective doses. And even when studies find low doses effective for some people, manufacturers often exclude these findings in their labeling information. …