What is the treatment for Streptococcus (Strep) pneumonia?

From the Guidelines

Streptococcus pneumoniae infections are typically treated with antibiotics, with ampicillin or penicillin being the first-line treatment for susceptible strains, as recommended by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America 1. For children with strep pneumonia, the treatment guidelines recommend the following:

• For Streptococcus pneumoniae with MICs for penicillin <2.0 µg/mL, the preferred parenteral therapy is ampicillin (150–200 mg/kg/day every 6 hours) or penicillin (200 000–250 000 U/kg/day every 4–6 hours), while the preferred oral therapy is amoxicillin (90 mg/kg/day in 2 doses or 45 mg/kg/day in 3 doses) 1.
• For S. pneumoniae resistant to penicillin, with MICs ≥4.0 µg/mL, the preferred parenteral therapy is ceftriaxone (100 mg/kg/day every 12–24 hours), while the preferred oral therapy is oral levofloxacin (16–20 mg/kg/day in 2 doses for children 6 months to 5 years and 8–10 mg/kg/day once daily for children 5–16 years; maximum daily dose, 750 mg), if susceptible 1. Some key points to consider when treating strep pneumonia include:
• The importance of starting treatment promptly, as S. pneumoniae can cause rapid clinical deterioration 1.
• The need to consider local resistance patterns when selecting antibiotic therapy, as antibiotic resistance is increasingly common 1.
• The potential for secondary sites of infection, including meningitis, in children with bacteremic pneumococcal pneumonia, and the need for particular caution when selecting alternatives to amoxicillin in these cases 2.

From the FDA Drug Label

In the treatment of pneumonia, azithromycin has only been shown to be safe and effective in the treatment of community-acquired pneumonia due to Chlamydia pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae or Streptococcus pneumoniae in patients appropriate for oral therapy Azithromycin should not be used in patients with pneumonia who are judged to be inappropriate for oral therapy because of moderate to severe illness or risk factors such as any of the following: patients with cystic fibrosis, patients with nosocomially acquired infections, patients with known or suspected bacteremia, patients requiring hospitalization, elderly or debilitated patients, or patients with significant underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia) Community-acquired pneumonia due to Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae or Streptococcus pneumoniae in patients appropriate for oral therapy

Treatment of strep pneumonia with azithromycin is indicated for community-acquired pneumonia due to Streptococcus pneumoniae in patients appropriate for oral therapy 3.

• The patient should not have moderate to severe illness or risk factors such as cystic fibrosis, nosocomially acquired infections, known or suspected bacteremia, or significant underlying health problems 3.
• Azithromycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria 4.

From the Research

Treatment Options for Strep Pneumonia

• Penicillin G is a recommended treatment for pneumococcal pneumonia, with high-dose therapy (20-24 million units per day) providing effective serum levels against most penicillin-resistant Streptococcus pneumoniae (PRSP) strains 5.
• The use of penicillin V has been studied as an alternative to amoxicillin for the treatment of non-severe pneumonia in adults, with a randomized controlled trial aiming to determine the efficacy of high-dose penicillin V compared to high-dose amoxicillin 6.
• Beta-lactam antibiotics, such as penicillin G, amoxicillin, and ceftriaxone, are recommended for the treatment of nonmeningeal pneumococcal infections, including pneumonia and sepsis 7.

Antibiotic Resistance and Treatment

• The emergence of penicillin-resistant Streptococcus pneumoniae has led to concerns about treatment effectiveness, but studies have shown that beta-lactam antibiotics can still be effective against strains with reduced susceptibility to penicillin 7, 8.
• The principles of pharmacodynamics predict that penicillin and cephalosporin therapy will be successful against pneumococci with minimum inhibitory concentrations of penicillin up to 4 micrograms/ml 8.
• New fluoroquinolones with excellent antipneumococcal activity may be considered for use in the setting of pneumonia caused by highly resistant pneumococci 8.

Novel Treatment Strategies

• Research has focused on boosting the host immune system and discovering novel antibacterials to prevent severe pneumococcal infections 9.
• Experimental therapies, such as selective antibodies and interference with pneumococcal virulence factors, have shown promise, but few have evolved to clinical trials 9.
• The discovery of novel antibacterials is ongoing, with novel enzymatic assays and target-based drug design allowing for the identification of targets and the development of new molecules to effectively treat Streptococcus pneumoniae infections 9.