1 of 7 Prescriptions Are Off-Label

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1 of 7 Prescriptions Are " Off-Label "

May 9, 2006

(USA TODAY) -- More than one of seven prescriptions

for common drugs are for off-label uses lacking

scientific support, a study suggests today.

Drugmakers seek Food and Drug Administration approval

for specific uses of their products and conduct trials

to test their drugs' safety and effectiveness in

patients with specific conditions. But once the FDA

approves a drug for one use, doctors can prescribe it

for whatever they want.

The study used data from the 2001 IMS Health National

Disease and Therapeutic Index to define prescribing

patterns for 160 commonly prescribed drugs

representing slightly more than half of all

prescriptions collected by IMS Health, which provides

prescription market data for drug and biotech

companies. IMS Health collects information about

prescribing and diagnoses from a random sample of

office-based doctors.

Study authors determined whether the prescription was

for an approved or off-label use. If off-label, they

then assessed the level of supporting scientific

evidence. Their reference was the DRUGDEX system, a

nationally recognized comprehensive summary of

evidence for approved and off-label uses of

prescription drugs.

In 2001, an estimated 150 million prescriptions -- or

21% -- for the 160 common drugs were for off-label

use, the authors write in the Archives of Internal

Medicine.

About 15% of prescriptions were for off-label uses

that lacked scientific support, the study found. " It

was surprising that three-quarters of off-label use

was in the absence of strong evidence, " says senior

author Randall Stafford, assistant professor of

medicine at Stanford Prevention Research Center.

Off-label prescribing was least common among drugs

used to control blood sugar in diabetes, pain

relievers and cholesterol-lowering drugs. It was most

common among heart drugs (excluding those for

cholesterol and high blood pressure) and

anticonvulsants, a type of seizure medication.

It's not clear why some drugs and types of drugs were

more likely to be prescribed for unsupported off-label

uses than others. The age of the drug,

direct-to-consumer advertising or the company that

made it made little difference, researchers said.

One explanation might be that " both physicians and

patients have misunderstood the role of the FDA, "

Stafford says. " I think there's sort of a presumption

that if a drug has made it onto the market, the FDA

has vouched for its safety and efficacy for all of its

potential uses. "

Patients should ask their doctors whether a

prescription is off-label and, if so, whether there

are good data to support it, he says.

In some cases, Stafford notes, scientific evidence for

off-label use is strong, but because the drug is

generic, no manufacturer stands to profit by pursuing

FDA approval for a new use.

Vanderbilt pharmacologist Alastair Wood suggests that

because patients often have multiple health problems,

some off-label prescribing in the study actually might

have been for approved uses that doctors had not

mentioned.

Still, Wood agreed that many treatment decisions lack

scientific support. " We need to do a better job of

pushing people to base the practice of medicine on

evidence, rather than anecdote. "

Copyright 2006 USA TODAY, a division of Gannett Co.

Inc.