From the Guidelines
For a patient with a dog bite who failed outpatient treatment with Augmentin, the recommended IV antibiotic is ampicillin-sulbactam (Unasyn) at a dose of 1.5-3g IV every 6 hours, as it provides excellent coverage against the mixed aerobic and anaerobic bacteria typically found in dog bites, including Pasteurella species, streptococci, staphylococci, and various anaerobes 1.
Key Considerations
- The choice of antibiotic is based on the likely pathogens involved in dog bites, which can include a variety of bacteria such as Pasteurella multocida, streptococci, staphylococci, and anaerobes.
- Ampicillin-sulbactam is a beta-lactam/beta-lactamase inhibitor combination that provides broad-spectrum coverage against these pathogens.
- Alternative options, such as piperacillin-tazobactam (Zosyn) 3.375g IV every 6 hours or a combination of a second-generation cephalosporin plus metronidazole, may also be considered based on the specific clinical scenario and patient factors.
Treatment Duration and Considerations
- Treatment duration typically ranges from 5-14 days, depending on the severity of the infection and the presence of any complications, such as abscesses or bone involvement.
- Patients with penicillin allergies may require alternative regimens, such as a fluoroquinolone (ciprofloxacin or levofloxacin) plus metronidazole, or clindamycin plus a fluoroquinolone.
- Surgical debridement may be necessary for severe infections, particularly those with abscess formation or necrotic tissue.
Evidence-Based Recommendations
- The Infectious Diseases Society of America (IDSA) guidelines recommend ampicillin-sulbactam as a first-line treatment option for dog bites, based on its broad-spectrum coverage and efficacy against common pathogens 1.
- Other studies have also supported the use of beta-lactam/beta-lactamase inhibitor combinations, such as piperacillin-tazobactam, for the treatment of dog bites 1.
From the FDA Drug Label
CLINICAL STUDIES Skin and Skin Structure Infections in Pediatric Patients Data from a controlled clinical trial conducted in pediatric patients provided evidence supporting the safety and efficacy of ampicillin and sulbactam for injection for the treatment of skin and skin structure infections Most patients received a course of oral antimicrobials following initial treatment with intravenous administration of parenteral antimicrobials
The best IV antibiotic for an inpatient with a dog bite who failed outpatient Augmentin (amoxicillin-clavulanate) treatment is Ampicillin-Sulbactam (IV), as it has shown similar outcomes to cefuroxime in treating skin and skin structure infections, with a clinical success rate of 85% 2.
- Key points to consider when using Ampicillin-Sulbactam (IV) include:
- A minimum of 72 hours of intravenous therapy
- No documented fever for prior 24 hours
- Improvement or resolution of the signs and symptoms of infection before transitioning to oral antimicrobial therapy
From the Research
IV Antibiotic Options for Inpatient Dog Bite Treatment
After failing outpatient Augmentin (amoxicillin-clavulanate) treatment, the choice of IV antibiotic for an inpatient with a dog bite should be based on the likely pathogens involved and their susceptibility patterns. The most common pathogens associated with dog bites include:
- Streptococcus species
- Staphylococcus species
- Pasteurella multocida
- Capnocytophaga canimorsus
- Anaerobic bacteria
Recommended IV Antibiotics
Given the polymicrobial nature of dog bite infections, broad-spectrum antibiotics are often recommended. Options may include:
- Ampicillin/sulbactam (Unasyn) 3
- A penicillin with a first-generation cephalosporin 4
- Clindamycin and a fluoroquinolone (for patients allergic to penicillins) 4
- Moxifloxacin, which offers broad coverage of the pathogenic flora 5
Considerations for Antibiotic Selection
When selecting an IV antibiotic, it is essential to consider the patient's allergy history and the potential for antibiotic resistance. In cases where the patient has multiple antibiotic allergies, careful selection must be made to ensure resolution of infection 3. Additionally, the need for prophylaxis against systemic infectious complications, such as tetanus, should be evaluated 5, 6.
Treatment Approach
Initial wound management, including irrigation and debridement, is crucial for preventing infection 5. The choice of IV antibiotic should be guided by the severity of the infection, the patient's overall health, and the results of any available culture and susceptibility data. In some cases, combination therapy may be necessary to ensure adequate coverage of the potential pathogens involved 4, 5.