From the Research
Keflex (cephalexin) is not typically recommended as a first-line treatment for pneumonia. While it is effective against some bacteria that can cause respiratory infections, it lacks coverage against atypical pathogens and drug-resistant Streptococcus pneumoniae commonly associated with pneumonia. For community-acquired pneumonia, broader-spectrum antibiotics like amoxicillin-clavulanate, respiratory fluoroquinolones, or macrolides are generally preferred, as seen in a study comparing the efficacies of intravenous azithromycin plus ceftriaxone and intravenous levofloxacin with step-down oral therapy for hospitalized patients with moderate to severe community-acquired pneumonia 1.
If cephalexin must be used, the standard adult dosage is 500 mg orally every 6 hours or 1 gram every 12 hours for 7-14 days, depending on infection severity. However, it's crucial to consider the limitations of cephalexin in treating pneumonia, especially against drug-resistant Streptococcus pneumoniae, as highlighted in a study discussing the appropriate use of antimicrobials for drug-resistant pneumonia 2.
Regarding lactation safety, cephalexin is considered compatible with breastfeeding as only small amounts pass into breast milk, and it has not been associated with adverse effects in nursing infants, similar to other medications classified as Lactation Risk Category L1 (safest). Patients with pneumonia should seek proper medical evaluation for appropriate antibiotic selection based on likely pathogens, local resistance patterns, and individual risk factors, as using an inadequate antibiotic could lead to treatment failure and worsening infection, a concern also raised by a study on the poor outcomes of empiric ceftriaxone ± azithromycin for community-acquired pneumonia caused by methicillin-susceptible Staphylococcus aureus 3.
Key points to consider:
- Cephalexin's effectiveness against certain respiratory pathogens
- The need for broader-spectrum antibiotics in community-acquired pneumonia
- Dosage and administration of cephalexin for pneumonia
- Lactation safety of cephalexin
- Importance of proper medical evaluation for antibiotic selection in pneumonia treatment, considering the findings from studies on doxycycline vs. levofloxacin in the treatment of community-acquired pneumonia 4 and the use of cephalexin in upper respiratory tract infections 5.