Common Asthma Drugs Could Prevent Fatal Pneumonia

Researchers recently discovered that drugs used to treat asthma and allergies may also be able to prevent a fatal form of pneumonia.

Influenza pneumonia occurs when the infection spreads to the alveolar air sacs located deep within the lungs. While flu infections do not typically reach that far down in the lungs, when it does, it can be deadly.

“If infection is severe enough, and the immune response is potent enough, you get injury to these cells and are no longer able to get sufficient oxygen exchange," said researcher Thomas J. Braciale, MD, PhD. "As a result of the infection of the cells, you can develop lethal pneumonia and die."

However, early administration of the asthma drugs Accolate (zafirlukast) and Singulair (montelukast) may prevent infection of the alveolar cells, according to a study published by PLOS Pathogens.

"The excitement of this is the possibility of someone coming to see the physician with influenza that looks a little more severe than usual and treating them with the drugs Singulair or Accolate and preventing them from getting severe pneumonia," Dr Braciale said. "The fatality rate from influenza pneumonia can be pretty high, even with all modern techniques to support these patients. Up to 40%. So, it's a very serious problem when it occurs."

Influenza pneumonia is caused by a virus, which is unlike traditional pneumonia. The viral component of the condition makes it difficult to treat, and even more difficult to prevent.

"When we look at pandemic strains of influenza that have high mortality rates, one of the best adaptations of those pandemic viruses is their ability to infect these alveolar epithelial cells," said researcher Amber Cardani, PhD. "It's one of the hallmarks for certain strains that cause the lethality in these pandemics."

After influenza spreads to the lungs, the body’s immune response can severely damage the alveolar air sacs, according to the study. Prevention is key for this condition.

"It's an important observation the field is coming to," Dr Cardani said. "We really need to limit the infection of these lower respiratory airways."

In the study, the investigators found that alveolar epithelial cells are typically shielded from infection by alveolar macrophages. In certain cases, the virus can inhibit the macrophages from protecting the cells, which makes the epithelial cells vulnerable to infection, according to the study.

"It's not as though they lack alveolar macrophages, it's just that their alveolar macrophages don't work right when they get exposed to the flu," Dr Braciale said. "And those are the types of patients, who potentially would eventually go to the intensive care unit, that we think could be treated early in infection with Accolate or Singulair to prevent infection of these epithelial cells and prevent lethal infection."

Treatment with Accolate or Singulair was seen to prevent infection of the alveolar epithelial cells, according to the study.

Next, the study authors plan to consult with other investigators to determine if patients treated with the drugs are less likely to develop influenza pneumonia during a flu outbreak.

"This was a totally unexpected observation," Dr Braciale concluded. "When I told multiple colleagues who are infectious disease or pulmonary physicians, they were absolutely flabbergasted."