Would cephalexin cover both tonsillitis and urinary tract infections (UTIs)?

From the Guidelines

Cephalexin can be used to treat both tonsillitis and urinary tract infections (UTIs), but its effectiveness depends on the causative bacteria and local resistance patterns. Cephalexin is a first-generation cephalosporin antibiotic that works against many common bacteria causing these infections, including Streptococcus (common in tonsillitis) and E. coli (common in UTIs) 1. For tonsillitis, the typical adult dose is 500 mg orally every 12 hours for 10 days, while for UTIs, adults usually take 500 mg orally every 12 hours for 7-14 days depending on infection severity 1.

Key Considerations

• Cephalexin is effective against many gram-positive and gram-negative bacteria, but resistance patterns may vary geographically 1.
• Patients should complete the full course of antibiotics even if symptoms improve, drink plenty of fluids, and contact their healthcare provider if symptoms worsen or don't improve after a few days of treatment.
• Local patterns of susceptibility of coliforms to antimicrobial agents, particularly trimethoprim-sulfamethoxazole and cephalexin, should be taken into account during selection of an antimicrobial agent before sensitivity results are available 1.

Dosage and Administration

• Adults: 500 mg orally every 12 hours for 7-14 days (UTIs) or 10 days (tonsillitis) 1.
• Children: weight-based dosing, typically 25-50 mg/kg/day divided into two doses 1.

Important Notes

• Cephalexin may not be effective against all bacteria, particularly certain strains of Staphylococcus or Pseudomonas 1.
• Patients should be informed about the importance of completing the full course of antibiotics and potential side effects of cephalexin 1.

From the FDA Drug Label

Cephalexin is indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms: ... Genitourinary tract infections, including acute prostatitis, caused by Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae Respiratory tract infections caused by Streptococcus pneumoniae and Streptococcus pyogenes

Cephalexin may cover both tonsillitis (a type of respiratory tract infection) and urinary tract infections (UTIs) (genitourinary tract infections), but only if the causative microorganisms are susceptible to cephalexin.

• The drug label lists Streptococcus pneumoniae and Streptococcus pyogenes as susceptible microorganisms for respiratory tract infections.
• The drug label lists Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae as susceptible microorganisms for genitourinary tract infections. 2

From the Research

Cephalexin Coverage for Tonsillitis and Urinary Tract Infections (UTIs)

• Cephalexin is a first-generation cephalosporin antibiotic that has been used to treat various bacterial infections, including tonsillitis and UTIs 3, 4, 5.
• For tonsillitis, cephalexin has been shown to be effective in treating pharyngitis and tonsillitis caused by beta-haemolytic streptococci, with a comparable clinical response and bacteriological cure rate to penicillin, cyclocillin, and cephaloglycin 4.
• For UTIs, cephalexin has been found to be effective in treating uncomplicated lower urinary tract infections (uLUTIs) caused by non-extended-spectrum beta-lactamase-producing (ESBL) Enterobacteriaceae, with a high clinical and bacteriological cure rate 3, 5.
• The optimal dosing for cephalexin in treating UTIs has been studied, with twice-daily dosing being as effective as four-times-daily dosing 3.
• Cephalexin may be a useful alternative therapy for the treatment of UTIs, especially in areas where resistance to other antibiotics is common 5.
• However, it is essential to note that cephalexin may not be effective against all types of bacteria that cause tonsillitis and UTIs, and the choice of antibiotic should be based on the specific causative pathogen and its susceptibility pattern 4, 6, 7.

Key Points

• Cephalexin is effective against tonsillitis caused by beta-haemolytic streptococci 4.
• Cephalexin is effective against uncomplicated lower urinary tract infections (uLUTIs) caused by non-ESBL Enterobacteriaceae 3, 5.
• Twice-daily dosing of cephalexin is as effective as four-times-daily dosing for UTIs 3.
• Cephalexin may be a useful alternative therapy for UTIs, especially in areas where resistance to other antibiotics is common 5.