Question: What do hot flashes, migraine headaches, and restless legs have in common?
Answer: Clonidine (generic and Catapres), a drug that's been used off-label to treat those and numerous other conditions, including attention-deficit/hyperactivity disorder (ADHD), sleep apnea, smoking cessation, Tourette's syndrome, and withdrawal from alcohol and narcotics.
If clonidine sounds like a remedy for all ills, bear in mind that it's approved by the Food and Drug Administration only to treat high blood pressure, and as an injection in combination with other medications, to ease severe cancer pain.
However, it's likely that doctors prescribe clonidine for more off-label uses than for its approved use. But the evidence for many of those off-label uses consists of only a few studies that are too small or that have other shortcomings which prevents making a clear recommendation. Where the evidence is sufficient to support its use, clonidine is generally recommended as a second-choice or additional medication when preferred treatments aren't effective or can't be used.
Available as a pill, skin patch, or an injection, clonidine works by controlling certain nerve impulses. As a result, it decreases your heart rate and relaxes blood vessels so that blood can flow more easily through the body. Studies indicate that it can be useful sometimes for the following off-label indications:
ADHD. If the most effective treatments for this disorder—stimulant drugs such as methylphenidate and dextroamphetamine—don't improve your child's behavior, clonidine may help control some symptoms such as hyperactivity and impulsiveness. A 2008 randomized, placebo-controlled trial involving 122 children with ADHD found that the drug offered some benefit in the home setting but was reported to be less effective in the classroom based on parent and teacher surveys to assess the child's ADHD symptoms.
Studies suggest that clonidine may be more valuable as an adjunct medication to treat secondary ADHD symptoms and the side effects of stimulants. Those may include aggression, jittery behavior, irritability, tics, and insomnia. Clonidine is among the most commonly prescribed drugs to treat insomnia for children with ADHD, according to a survey of more than 1,200 child psychiatrists. However, the American Academy of Sleep Medicine advises first trying behavioral strategies for pediatric insomnia and using medication sparingly. Consumer Reports medical advisors urge people to avoid taking medication to treat the side effects of another drug unless that drug is essential.
Hot flashes. Estrogen-replacement therapy is the most effective treatment for this menopausal symptom, but it increases the risk of stroke, blood clots, and breast cancer. Consequently it's not recommended for many women, particularly those who have had breast cancer.
Studies suggest that clonidine modestly improves the severity and frequency of hot flashes in some women, and it's a sensible choice for those who also suffer from high blood pressure. It may also be useful for breast-cancer survivors who are taking tamoxifen, a drug that reduces the chance that cancer will recur but also induces hot flashes. However, a 2007 randomized trial by the European Society for Medical Oncology found that the antidepressant drug venlafaxine was more effective than clonidine for reducing hot flashes in breast-cancer patients.
Want to find out about other drugs commonly prescribed off-label? Read more here.
Smoking cessation. Nicotine replacement products and the antidepressant drug bupropion sustained-release (Zyban and generic) are more effective and have fewer side effects than clonidine for smokers who are trying to kick the habit. If those first-line treatments don't work or can't be used, clonidine may be an effective alternative. A 2008 report from the U.S. Public Health Service concluded that it about doubles the odds of quitting compared with placebo.
Opioid and alcohol withdrawal. Clonidine is used as a non-narcotic alternative to methadone for reducing withdrawal symptoms in people who are trying to stop taking opiate drugs such as morphine and heroin. A review of more than 20 controlled studies found that clonidine and methadone were about equally effective, although clonidine caused more unwanted side effects.
When used in conjunction with other drugs to manage alcohol withdrawal, clonidine can reduce elevated blood pressure, increased heart rate, tremors, sweating, and anxiety.
Tourette's syndrome. Clonidine is sometimes used to treat the involuntary, repetitive movements or sounds that characterize this disorder. While dopamine-receptor-blocking drugs such as haloperidol and pimozide are more effective, they don't completely eliminate tics and they may cause unpleasant side effects. Clonidine may be helpful when used in conjunction with those medications or, if symptoms are mild, used alone. Moreover, it's a good choice for patients who have Tourette's syndrome with ADHD because it also reduces insomnia, hyperactivity, and impulsivity.
Restless legs syndrome (RLS). Although not a first-line treatment for this disorder, clonidine may be effective for a short time if the syndrome is not due to other conditions or medications. There's not enough evidence to recommend it for RLS that's due to iron deficiency or other secondary causes.
What are the risks of clonidine?
Common side effects include: constipation, dizziness, drowsiness, dry mouth, headache, fainting, nausea, nervousness, reduced sexual ability, tiredness, vomiting, and weakness. Older people and those who weigh less than average or have kidney problems may experience confusion.
What precautions can you take?
Clonidine may worsen heart disease and have heightened effects in people with kidney disease. Tell your doctor if you have those conditions or a history of heart attack or stroke.
Inform your doctor of all prescription and over-the-counter drugs or supplements you're taking. Interactions with other medications—such as antidepressants, beta blockers,calcium channel blockers, digoxin, or tranquilizers—may increase clonidine's side effects and its effects on your blood pressure and heart rate.
Because clonidine has sedative effects, don't drive a car or operate machinery until you know how the drug affects you. Be cautious about using alcohol or sedating drugs while taking clonidine.
Clonidine may cause dizziness or fainting when you rise too quickly from a lying position. Instead, get out of bed slowly, resting your feet on the floor for a few minutes before standing.
The clonidine skin patch may cause a rash. Continuing to use it, or switching to the oral version, may trigger an allergic reaction.
To relieve dry mouth, chew gum or suck sugarless hard candy. If the condition persists for more than two weeks, check with your doctor or dentist. Prolonged dry mouth may increase the risk of dental disease.
Sudden discontinuation of clonidine can cause a rapid rise in your blood pressure as well as nervousness, headache, and uncontrollable shaking. Before stopping the drug, contact your doctor, who will reduce the dosage gradually to prevent those symptoms.
If you're having medical or dental surgery, tell the doctor or dentist that you're taking clonidine.
Additional safety precaution for ADHD patients. Cardiovascular risks should be evaluated before starting clonidine for the treatment of ADHD. Some patients have reported changes in heart rate or rhythm.
Patients should be monitored for changes in pulse and blood pressure, and sedation while using clonidine.
Bottom line. Clonidine is a widely used drug for children, adolescents, and adults. Our advice: Talk to your doctor about all drug and non-drug treatment options for your condition. If first-line medications aren't effective or you can't tolerate them, ask your physician if there's sufficient evidence to use clonidine.
This off-label drug use report is made possible through collaboration between Consumer Reports Best Buy Drugs and the American Society of Health-System Pharmacists. This is the fourth article in a series based on professional reports prepared by ASHP. These materials were made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by the multi-state settlement of consumer fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).
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