People with pneumonia are failing treatment at an alarming rate, and doctors are in for a wake-up call.

Pneumonia is already the eighth leading cause of death in the United States, particularly for older adults.

Antibiotic-resistant strains only make it more dangerous.

Researchers from the American Thoracic Society studied medical records of 250,000 people with pneumonia from 2011 to 2015, and concluded as many as 1 in 4 were not cured by an initial course of antibiotic treatment.

Almost 10 percent of those people had to seek help from an emergency room or required hospitalization.

These pneumonia cases also had the distinction of being community-acquired pneumonia (CAP), meaning that patients caught these strains outside of a hospital or nursing home setting — sites where antibiotic-resistant bacteria are commonly found.

“Pneumonia is the leading cause of death from infectious disease in the United States, so it is concerning that we found nearly 1 in 4 patients with community-acquired pneumonia required additional antibiotic therapy, subsequent hospitalization, or emergency room evaluation,” said lead researcher, Dr. James A. McKinnell, MD, in a statement.

Read more: Get the facts on pneumonia »

A deadly disease

According to the Centers for Disease Control and Prevention (CDC), pneumonia causes more than 50,000 deaths in the United States each year.

McKinnell and his team evaluated what they called “initial treatment failure” based on the following criteria:

  • if the patient needed to return to their doctor for more of the same antibiotic
  • if the patient needed a different antibiotic
  • if the patient was either sent to an emergency room or was hospitalized

“What we were trying to do is highlight to doctors that more patients fail that initial treatment than many doctors would imagine,” Glenn Tillotson, a co-researcher, told Healthline.

Resistance for common pneumonia treatments like Zithromax, commonly called a Z-Pak, can be as high as 50 percent of strains, said Tillotson.

Read more: How doctors treat COPD patients who have pneumonia »

Young and old

The danger of pneumonia becomes increasingly risky for the very young, and for those over the age of 65.

About 85 percent of all pneumonia deaths occur in those over the age of 65, according to the American Lung Association.

“Our data provide numerous insights into characteristics of patients who are at higher risk of complications and clinical failure,” said McKinnell “Perhaps the most striking example is the association between age and hospitalization. Patients over the age of 65 were nearly twice as likely to be hospitalized compared to younger patients.”

“Elderly patients are more vulnerable and should be treated more carefully, potentially with more aggressive antibiotic therapy,” he said.

Tillotson concurred. He told Healthline that in high-risk cases, such as with older adults, it might be smarter to begin treatment with two antibiotics, rather than using a wait-and-see approach to treating pneumonia.

“None of the drugs we are talking about are branded, expensive things, they are all generic. So, if you have someone that is at risk go for two drugs at once. Be sure, rather than be hesitant,” he said.

Read more: Is pneumonia contagious? »

A high priority

New treatments for antibiotic-resistant infections are a high priority for researchers all over the world.

However, until those arrive, Tillotson said that doctors can help with pneumonia treatment by paying attention to risk factors and modifying prescribing habits.

“We have a death rate with pneumonia that is perhaps unacceptably higher than we would expect,” said Tillotson.

Without some change to current pneumonia treatment, the seriousness of the illness will only worsen.