What is the best treatment plan for a 63-year-old male patient with onychomycosis of the left great toenail and a suspected bacterial infection of the right second toe, for which Lamisil (terbinafine) 1% cream and Keflex (cephalexin) 1000 mg are prescribed?

From the Guidelines

The patient's treatment plan should prioritize the use of antibiotics and antifungals, with a focus on addressing both bacterial and fungal components of the infection, as evidenced by the most recent guidelines from the Infectious Diseases Society of America and the World Health Organization 1. The patient's current treatment plan, which includes Keflex (cephalexin) 1000 mg twice daily for 10 days and Lamisil (terbinafine) 1% cream twice daily for 3 months, is a reasonable approach to addressing the infection.

• The use of cephalexin provides broad-spectrum antibiotic coverage against common skin pathogens, including Staphylococcus aureus and Streptococcus pyogenes.
• The addition of terbinafine cream addresses the potential fungal component of the infection, which is common in toe infections. Key considerations in the treatment plan include:
• Monitoring the patient's response to treatment and adjusting the antibiotic regimen as needed based on culture and sensitivity results.
• Ensuring the patient understands the importance of completing the full treatment course and potential side effects of the medications.
• Considering the use of topical or oral antifungals, such as terbinafine, to address any fungal components of the infection, as recommended by the British Association of Dermatologists' guidelines for the management of onychomycosis 1. The patient's treatment plan should be guided by the most recent and highest-quality evidence, including the 2024 WHO Essential Medicines and Aware recommendations on first- and second-choice antibiotics for empiric treatment of clinical infections 1.
• This approach ensures that the patient receives evidence-based care that prioritizes their morbidity, mortality, and quality of life outcomes.

From the FDA Drug Label

Cephalexin is indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms: ... Skin and skin structure infections caused by Staphylococcus aureus and/or Streptococcus pyogenes Note—Culture and susceptibility tests should be initiated prior to and during therapy. The patient has an infection on his right second toe, and cephalexin is prescribed. Cephalexin is indicated for skin and skin structure infections. However, the FDA label advises that culture and susceptibility tests should be initiated prior to and during therapy 2. In this case, a wound culture of the right second toe was performed, which is appropriate. The results of the culture will help determine the most effective treatment. It is essential to follow the culture results to ensure the infection is caused by susceptible strains of the designated microorganisms.

From the Research

Wound Infection and Treatment

• The patient's infection on the right second toe is being treated with Keflex 1000 mg BID for 10 days, which is a suitable antibiotic for skin and soft-tissue infections, as shown in a study from 1983 3.
• A wound culture of the right second toe was performed to determine the most effective treatment moving forward, which is in line with the recommendation to perform cultures on chronic wounds when clinical signs of infection are present, such as pain, necrotic tissue, delayed healing, and wound deterioration 4.
• The use of Lamisil 1% cream BID for 3 months to treat the infection is also being considered, although it is primarily an antifungal medication, and the presence of fungi in wounds can be significant, as discussed in a 2018 study 5.

Wound Culture and Infection Identification

• The decision to perform a wound culture is supported by a 2009 study that recommends culturing after a clinical diagnosis of infection is made to identify the causative organisms and guide antibiotic therapy 6.
• A 2018 study suggests that quantitative culture of wound tissue is the gold standard, but the swab method is an acceptable alternative option, and the Levine technique is more reliable than the Z-technique to determine microbial load in the wound bed 4.

Treatment and Management

• The treatment plan, including the use of antibiotics and antifungal medications, is aimed at managing the wound infection and promoting healing, as discussed in a 2021 overview of wound infections 7.
• The patient's understanding and willingness to comply with the treatment plan are crucial for effective management of the wound infection, and ongoing monitoring and adjustment of the treatment plan may be necessary based on the results of the wound culture and the patient's response to treatment.