When there's little proof a prescription drug will work

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When there's little proof a prescription drug will work

'Off-label' medicines are becoming more popular even though they

often lack scientific support, a new study shows.

By Shari Roan, Times Staff Writer

http://www.latimes.com/features/health/la-he-

offlabel15may15,1,1436271.story?coll=la-headlines-health

Millions of Americans each year are prescribed drugs that are not

approved for their specific medical condition, a practice that is

legal and logical in many cases. But a new study has found that fully

20% of all prescriptions are written for such nonapproved uses and

that most of these — three-quarters — are not well-supported by

scientific studies.

This widespread use of medications " off-label " could threaten

patients' safety while escaping the attention of federal regulators,

some experts suggest.

" What surprised me about this study is that in many cases there is a

paucity of scientific studies supporting the drug's use off-label, "

says I. Kaitin, director of the Tufts Center for the Study of

Drug Development. " It's an issue that should be discussed in the

medical community. " Still, Kaitin says, it's unclear whether

consumers are being put at undue risk. " There has not been a

significant problem with off-label prescribing that I'm aware of, " he

says.

The study, published last week in the Archives of Internal Medicine,

polled 3,500 randomly selected doctors on all of their patient

interactions over two consecutive days in 2001, including any drugs

they may have prescribed. Researchers then retrieved information on

the 100 most commonly prescribed drugs as well as 60 more drugs that

were randomly selected.

Among other things, the scientists found that cardiac medications,

anticonvulsants and asthma medications were the most likely to be

prescribed off-label. Psychiatric drugs and allergy medications were

the most likely types of drugs to be used off-label with little

scientific support. In fact, scientific support was lacking for 96%

of the psychiatric drugs prescribed off-label.

Dr. Randall S. Stafford, lead author of the study and an associate

professor of medicine at the Stanford Prevention Research Center,

said the findings were troubling. Even though drugs are thoroughly

reviewed by the Food and Drug Administration before they're allowed

to go to market, " the FDA does not vouch for the safety and efficacy

of all the various ways that drugs are used, " he says.

Drugs, he adds, are tested and approved at specific doses with

detailed information about side effects that occurred during the

trials — but those data may be irrelevant when a medication is used

for a different diagnosis and in different types of patients.

Off-label use of drugs is not rare. Once a drug reaches the market,

doctors can legally prescribe it for any diagnosis. This long-

standing practice has been lauded for allowing doctors the freedom to

treat their patients based on the latest scientific studies and

clinical information.

In certain areas of medicine, such as pediatrics, off-label use of

medications is almost unavoidable because, until recently, drug

manufacturers were not required to conduct research on how their

products affect children. And in cancer treatment, off-label use

allows doctors to try different strategies for seriously ill patients

who have exhausted all other options.

Off-label use also makes sense when the drug is used for a condition

very similar to its approved indication. For example, Stafford says,

doctors can reasonably assume that a drug used to treat asthma will

be effective for other lung diseases.

" There are plenty of situations where off-label use is completely

legitimate, " says Stafford, " But there are other ways that drugs are

used that are quite distinct from the FDA indication and where we

don't have good information. "

For example, he says, the Type 2 diabetes drug metformin is

frequently prescribed for women with polycystic ovary syndrome. And

gabapentin, a seizure drug, is widely prescribed for chronic pain. At

the time the study was undertaken, in 2001, there was some

preliminary evidence that those drugs had other beneficial uses, but

it was not substantial.

However, safety issues are more likely to come to the attention of

health regulators regarding an FDA-approved use of a drug than a

nonapproved use, Stafford says.

The study did not address why doctors prescribe so many off-label

medications bearing little scientific support. It is illegal for drug

company sales representatives to promote off-label uses, although

some experts think that practice occurs. (Pfizer, manufacturer of the

gabapentin drug Neurontin, was convicted in 2004 for inappropriate

marketing of off-label uses.)

Doctors often learn about novel drug uses from colleagues or from

preliminary studies. The desire to offer patients the latest

therapies may lead them to make a leap of faith with an off-label

drug, Stafford says.

Consumers should ask if the prescription they receive is approved for

their condition or has been adequately studied, he says.

Doctors " need to think about the degree of evidence that supports

what we do. "