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The patient who came to see Orly Avitzur, a neurologist and Consumer Reports’ medical director, informed her that another doctor had prescribed hydroxychloroquine (Plaquenil) to help her with symptoms of Raynaud’s disease. In this condition, exposure to cold causes blood vessels in the fingers and toes to spasm, leaving digits frigid and numb — and occasionally blue.

Plaquenil, used to decrease joint pain and swelling, is approved by the Food and Drug Administration for lupus and rheumatoid arthritis. But Avitzur’s patient insisted that she’d never been diagnosed with either condition. What she had was an off-label prescription.

Many doctors (Avitzur included) sometimes prescribe a drug off-label — for a different indication, population or age group than those for which it’s ­FDA-approved. Research published in 2006 suggests that 20 percent of prescriptions are off-label.

Off-label prescribing is legal, and there are some good reasons for its use. Doctors often turn to it to help patients who haven’t responded to drugs that are FDA-approved for their condition. Sometimes, as with Raynaud’s, there are no FDA-approved drugs. Doctors may also be tempted to prescribe an off-label drug when features of two conditions are similar.

But off-label prescribing can have drawbacks. For example, research suggests it can increase the risk of some side effects, which is what happened to Avitzur’s patient. She had been experiencing itchiness, an occasional side effect of Plaquenil­, for three years. Her skin was covered by cuts and scars from scratching.

To make sure you’re fully informed about the status of your medications, ask these five questions when you get a new prescription:

Is this an off-label use? Doctors often neglect to tell patients when they're recommending a drug off-label.

You can also find out by going to Daily Med (at dailymed.­nlm.­nih.­gov/dailymed). Search for the drug you take, then click on "Indications and Usage" to see whether your condition is listed.

Where's the evidence? If your doctor has prescribed a drug off-label, there may be a good reason. A professional medical society may have deemed it a safe and effective choice. Or solid scientific research may suggest it's useful for your condition.

But off-label prescribing is supported by strong evidence only about 20 percent of the time, according to a 2016 JAMA Internal Medicine study. And the research found that those receiving prescriptions for off-label indications that lacked strong evidence were 54 percent more likely to experience an adverse drug event than those who got prescriptions for on-label drugs.

What are the risks and side effects? You should ask this question about any new prescription, but it's especially important for off-label medications because the potential risks are higher. In the case of Avitzur's patient, the itching she experienced disappeared when she stopped taking Plaquenil. But some side effects can cause life-threatening or permanent damage.

Are there better options? If you're uncomfortable with the answers to the preceding three questions, ask whether ­FDA-approved drugs are available for your condition. And find out whether medication-free measures, such as physical therapy or talk therapy, might be an option. Nondrug treatments may be more effective than medication for conditions such as back pain, depression and insomnia.

Will insurance cover it? If you feel satisfied that an off-label use is appropriate, call your insurance company to make sure it will pay for the drug.

 Copyright 2017, Consumer Reports Inc.

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