Physicians generally recommend inhaled corticosteroids as the first drug for treating asthma. Inhaled corticosteroids, reaching the lungs quickly, have shown to be more effective than orally administered agents that are absorbed by the entire body.
However, a recent study pointed out that inhaled steroids might not be the best medicine for elderly patients with asthma. Inhalers are difficult to use, and its method differs depending on devices. Elderly patients, in particular, have difficulties using devices. That shows why there is a gap in efficacy between clinical trials conducted under controlled conditions and the actual sites of patient care.
|Professor of the Department of Allergy and Clinical Immunology at Asan Medical Center interviews with Korea Biomedical Review.|
Kim Tae-bum, a professor of the Department of Allergy and Clinical Immunology at Asan Medical Center, announced the results of a study that compared the effectiveness of leukotriene receptor antagonists (LTRAs) versus inhaled corticosteroids (ICSs) in elderly patients with asthma in real-world settings.
According to the study, the proportion of patients who did not have asthma exacerbation was not different between the group with LTRAs and that with ICSs. Also, there was no significant difference between the two groups in the proportion of patients who visited the hospital at least once due to asthma within one year of treatment.
However, the two groups had different medication possession ratios (MPR). While 17.9 percent of LTRAs group had an 80 percent or greater MPR, only 16 percent of the ICSs group did so.
Titled, “A Comparison of Leukotriene Receptor Antagonists to Low-Dose Inhaled Corticosteroids in the Elderly with Mild Asthma,” the study was published in May issue of Journal of Allergy and Clinical Immunology in Practice.
Korea Biomedical Review met with Kim to learn about asthma in the elderly and what the real-world study’s results meant.
Question: Many trials have proved that ICSs were more effective than oral agents in asthma treatment. The asthma treatment guidelines also recommend ICCs as the first therapy. Can you explain this further?
Answer: Asthma is a disease that occurs in the lungs. ICSs are absorbed directly into the lungs, making the drug reach the lungs faster than oral ones. They have bronchial dilators and are more effective. Findings have so far suggested that ICSs are generally more beneficial and effective than oral medicines. However, most of the existing studies could have selection biases because they were conducted in a controlled situation in a group of patients optimized for the studies. There could be limitations in terms of age because clinical trials mainly target patients aged between people in their 30s and those in their 60s who have no other disease and are nonsmokers. Therefore, it is getting more critical to conduct a real-world study to confirm the effects of drugs on the various patient groups in everyday life rather than studying a particular patient group.
Because there have been few clinical trials for the elderly, our finding is more meaningful. We studied 1,692 elderly patients. Considering things such as drug compliance and inhalation techniques in real-world settings, the study has confirmed that oral drugs, especially LTRAs, may be as effective as ICSs in the elderly.
Q: How large is the proportion of patients older than 65 who cannot use inhalers properly?
A: It should be about 30 percent. Around 10 percent are unable to enjoy the benefit because they don’t know how to use it. Considering some misuse it and only a part of the drug is absorbed, the proportion should be about 30 percent.
Q: How different are the side effects between oral agents and inhalers?
A: Among oral drugs, I will explain about LTRAs, which were used for the study. LTRAs rarely cause significant side effects even in long-term use, although some could experience insomnia. ICSs are known to have no serious side effects, but if steroids remain in the mouth, the patient can develop Candida fungi. As steroids go into the body, they could paralyze vocal cords’ muscles, causing a weak voice or cough. ICSs have fewer side effects than oral agents, but if ICSs are accumulated in the body, they could cause osteoporosis in elderly patients.
If we talk about only side effects, LTRAs have fewer side effects than ICSs.
Q: This study targeted only people with mild asthma. If we look at only the results, it’s possible to interpret that oral agents work better than inhalers at the initial stage of elderly asthma. Isn’t it?
A: It would be overstretched to say so. In a study based on real-world settings, there is a limitation in saying which one is better, even if there are differences in the interpretation of the results. Because the study was based on data from the Health Insurance Review and Assessment Service, it is not possible to determine the cause of the patient's transition to an oral drug. Reasons may vary: the inhaler might not be effective, the patient used it inadequately, or the patient didn’t want to use the inhaler. This is a limitation to a real-world study.
Thus, it is difficult to conclude that oral drugs are better than inhalers in asthma. Instead, we could say that oral agents are not inferior to inhalers in elderly patients with mild asthma. Doctors could use inhalers as the first therapy under the current guideline, and use oral agents for the second therapy. I concluded that if the use of inhalers is difficult, it could be used for the first therapy. What’s important is this is limited only to patients with mild symptoms. If asthma gets worse to modest and severe asthma, it is hard to treat it only with oral drugs.
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