Antibiotic use among elderly people with pneumonia: A Japanese perspective

26 January, 2022

Professor Naoyuku Miyashita
Department of Respiratory Infectious Diseases and Allergies,
Department of Internal Medicine, Kansai Medical University


Community-acquired pneumonia (CAP) and aspiration pneumonia are common acute infectious diseases among elderly people and are associated with high hospitalisation rates and mortality.1 A local study has shown that hospitalisation due to pneumonia in elderly Japanese patients leads to functional decline, especially among patients with nursing and healthcare-associated pneumonia.2

Professor Miyashita shares insights into the importance of rendering treatment for aspiration pneumonia and community-acquired pneumonia (CAP) among elderly patients in Japan and the role of sitafloxacin for treating elderly patients with cognitive impairment and pneumonia.


Q1: Please describe the aetiology and epidemiologic profile of CAP and aspiration pneumonia among the elderly in Japan, both in the inpatient and outpatient setting.

Like the rest of the world, the three most common causative organisms of CAP in Japan are Streptococcus pneumoniae, Haemophilus influenzae and Mycoplasma pneumoniae. In addition to these, oral commensal bacteria, especially oral streptococci and anaerobic bacteria, are common in the elderly and hence important targets. Conversely, we rarely need to consider mycoplasmas in CAP in the elderly.

Aspiration pneumonia makes up most cases of NHCAP and is caused by oral streptococci such as S. pneumoniae. As such, unlike Europe and America, NHCAP in Japan is not dominated by methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, but by oral streptococci and anaerobic bacteria instead.

Hospitalisation is common among many elderly NHCAP patients. While many patients who experience aspiration have lowered activities of daily living (ADL), many delay medical intervention until after the disease have exacerbated. Oftentimes, medical attention is only sought after families noticed their severe symptoms. Early intervention would allow them to be treated as outpatients. Many who visit the clinics and university hospitals are outpatients.


Q2: Please describe the treatment strategies and outcomes for pneumonia, especially aspiration pneumonia, among elderly patients in Japan. Do the treatments differ between inpatient and outpatient settings?

Prevention is critical when it comes to treatment strategies. This is also mentioned in the guidelines.3 Antibiotic options include drugs with antimicrobial activity against anaerobic bacteria such as β-lactamase inhibitors and drugs that allow high tissue absorption. For outpatients, the standard therapy is usually drugs to be taken once a day such as ceftriaxone and quinolones. For inpatients, penicillins such as sulbactam/ampicillin which contain β-lactamase inhibitors are the first choice. Outpatients are sometimes transitioned to oral medication after receiving intravenous medication.

Prevention is prioritised over treatment for aspiration pneumonia. The first pillar of prevention is to strengthen the immune system through vaccination and nutrition. The second pillar is to improve swallowing ability. These preventative measures should be taken daily and are of utmost importance. Strategies to improve swallowing ability include using drugs to activate substance P, leaflet-guided rehabilitation exercises (exercise therapy such as swallowing exercises) three-times a day and improving bowel peristalsis and constipation.


Q3: What is the role of fluoroquinolones – particularly sitafloxacin – in the treatment of outpatient aspiration pneumonia, including antimicrobial resistant forms, among elderly patients?

The advantages of using sitafloxacin are its strong antimicrobial activity against anaerobic bacteria and oral streptococci, efficient tissue absorption, and ease of use in elderly patients because of its favourable safety profile.


Q4: What precautions need to be taken when using fluoroquinolones for the elderly?

It is common practice to check the elderly patient’s renal functions, but because the antibiotics are not for long term usage (usually for only about 1 week), slight decreases in renal function would not be an issue for outpatient treatment. However, for inpatient treatments, many patients suffer from dehydration hence dosage adjustment is necessary.

It is also important to note that elderly patients often take many other medications concurrently. In particular, heart diseases are common among the elderly. Hence, precautions must be taken as anti-arrhythmia medications have absolute contraindications with certain antibiotics. Drugs with multiple relative contraindications are thus difficult to prescribe to the elderly. Although levofloxacin has the least drug interactions, it has weak antimicrobial activity against anaerobic bacteria. That is why sitafloxacin, which has little relative contraindications and no absolute contraindications, is easy to prescribe for the elderly.


Q5: What is the relationship between cognitive impairment and pneumonia?

When the elderly are hospitalised, such irregular situations can cause a decrease in ADL and incite delirium. With time, this can impact cognitive function. Usually, patients will eventually recover from delirium. However, it was found that 25% of those with moderate or severe pneumonia do not recover and suffer from sustained cognitive impairment (e.g. memory loss) after discharge. Therefore, it is important to maintain ADL and prevent pneumonia, or to treat pneumonia in an outpatient setting as much as possible.


Q6: What are the advantages of using sitafloxacin in patients with cognitive impairment, including those with Alzheimer’s disease?

The advantages of using sitafloxacin in patients with cognitive impairment is the ease of adherence to treatment. This is especially since it is a once-daily oral medication where the tablets are small and easy to swallow as well. Data suggest that those with cognitive impairment may be predisposed to aspiration.4 Hence, it is important to choose antibiotics that target oral streptococci and anaerobic bacteria in patients with cognitive impairment.

Meta-analysis has shown that there is an association between periodontal disease and Alzheimer’s disease.5,6 However, periodontal disease is linked to many other illnesses, including diabetes. Periodontal disease is linked to diabetes as high blood sugar levels often make it easier for bacteria to grow. At the same time, diabetes causes narrowing of the microvasculature, which is associated with Alzheimer’s disease and mild dementia. Lack of proper oral care in the elderly and diabetic patients can lead to serious issues.


Q7: Can you give us some advice to sum up?

On top of antimicrobial resistance (AMR), it has also been brought to light that elderly and patients with underlying medical conditions are at risk of developing pneumonia, during the current coronavirus pandemic. When these people contract pneumonia, their ADL declines and they are more likely to suffer from recurring aspiration pneumonia, leading to dementia. To avoid this vicious circle, healthcare professionals should promote prevention through vaccination and improving swallowing ability. At the same time, I think the right option is early intervention with antibiotics as well. Adopting AMR strategies does not mean completely avoiding the use of antibiotics.



  1. Konomura K, et al. Pneumonia 2017;9:19.
  2. Kato T, et al. J Infect Chemother. 2016;22(10):662-6.
  3. The Japanese Respiratory Society. The JRS Guidelines for the Management of Pneumonia in Adults 2017. Available at: Accessed: December 2021
  4. Mitchell SL. N Engl J Med 2015;372:2533-40.
  5. Leira Y, et al. Neuroepidemiology 2017;48:21-31.
  6. Hu X, et al. Psychogeriatrics 2021;21:813-25.