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Antibiotic May Help Asthma Attacks

Fewer Asthma Symptoms, Faster Improvement With Ketek -- but Why?
WebMD Health News
Reviewed by Louise Chang, MD

April 12, 2006 -- The antibiotic Ketek helps people with worsening asthma, a clinical trial suggests.

Doctors call it acute exacerbation of asthma. It is when a person's usual asthma gets suddenly worse. Sometimes it starts with an asthma attack that forces a person to seek medical care. Other times it simply means feeling run down, with breathing difficulty and a cough.

Why does asthma get worse? There's a theory that atypical bacteria may colonize the lungs of people with asthma. Ketek is an antibiotic that kills these unusual suspects.

This theory wasn't very convincing to respiratory disease expert Sebastian L. Johnston, MD, PhD, of the U.K.'s National Heart-Lung Institute at Imperial College, London. So he put it to the test. He led an international study that added Ketek -- or an inactive placebo -- to the usual care of 278 adults who'd just had an asthma attack.

"Ketek showed a pretty impressive effect," Johnston tells WebMD. "Symptoms improved nearly twice as much in those receiving the treatment as in those receiving placebo. Lung function did the same. In terms of speed of recovery, time to 50% improvement was five days vs. eight days -- three days faster. It was a surprisingly large treatment effect."

The findings appear in the April 13 issue of The New England Journal of Medicine.

Bacteria May Not Be to Blame

Does this prove that atypical bacteria are behind worsening asthma? No, says an accompanying editorial by Frédéric F. Little, MD, of the Boston University School of Medicine. Little notes that more than half of the patients in the study had antibodies against atypical bacteria in their blood. But those who had this sign of infection were no more likely to respond to Ketek than those never infected with the germs.

"My interpretation is that the benefit of Ketek was not related to its antibacterial effect," Little tells WebMD. "Some antibiotics have anti-inflammatory effects. Ketek is a new class of antibiotics related to [another class of antibiotics] that have been helpful as anti-inflammatory agents."

"It is possible Dr. Little is right -- these effects of Ketek may have had nothing to do with bacterial infection -- but I would not yet conclude this is so," Johnston says. "It may be that bacterial infection had no influence on the patients' asthma. But I am very cautious about how good our diagnostic methods are for these atypical organisms. We need to learn more."

Too Soon to Prescribe Ketek for Asthma

As impressive as Johnston finds the effects of Ketek, he says it's far too soon to know whether it really helps asthma patients.

"We need to confirm these results," Johnston says. "When you have a reasonably small study challenging treatment guidelines and clinical practice in every country in the world, you need confirmation with a second study. I anticipate treatment practice will change, but it is too soon to change it now."

Because it still isn't clear why Ketek might help asthma patients -- and because a single study proves nothing -- Little, too, advises against taking Ketek for asthma.

"Patients should not be clamoring to their doctors saying this is proof that antibiotics help asthma exacerbations," Little says. "Neither doctors nor patients should read this study and conclude that antibiotics are a recommended treatment for asthma."

Ketek does have side effects. Patients who took Ketek in the Johnston study were more likely to report nausea. And last January, there were reports of patients suffering serious liver damage after taking Ketek.

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