Antibiotic Recommendations for Lacerations
For most simple, clean lacerations, prophylactic antibiotics are not indicated, as incision and drainage or proper wound care alone achieves cure rates exceeding 90%. However, specific high-risk scenarios require targeted antibiotic therapy.
When Antibiotics Are NOT Needed
Most simple, uncomplicated lacerations do not require prophylactic antibiotics. 1, 2
- Clean lacerations without significant contamination have infection rates of only 6-7% regardless of antibiotic use 1
- Proper wound irrigation, debridement, and closure are more important than antibiotics for preventing infection 3
- Even in contaminated wounds, studies show no significant difference in infection rates between antibiotic and no-antibiotic groups when proper wound care is performed 1
When Antibiotics ARE Indicated
Preemptive antibiotic therapy for 3-5 days is recommended for patients with specific high-risk features: 3
- Immunocompromised status 3
- Asplenia 3
- Advanced liver disease 3
- Preexisting or resultant edema of the affected area 3
- Moderate to severe injuries, especially to the hand or face 3
- Injuries that may have penetrated the periosteum or joint capsule 3
- Heavy contamination with soil, organic matter, or fecal material 4, 5
First-Line Antibiotic Choice
Amoxicillin-clavulanate 875/125 mg orally twice daily is the preferred antibiotic for contaminated traumatic wounds requiring coverage. 3, 4
- This agent provides optimal coverage for both aerobic and anaerobic bacteria commonly found in contaminated wounds 3
- It covers Staphylococcus aureus, streptococci, gram-negative organisms, and environmental bacteria 4
- The clavulanate component protects against beta-lactamase producing organisms 5
Alternative Regimens for Penicillin Allergy
For mild penicillin allergy: 4
For severe penicillin allergy: 4
- Doxycycline 100 mg orally twice daily PLUS metronidazole 500 mg orally three times daily 4
Duration of Therapy
Antibiotic treatment should be 3-5 days for soft tissue injuries without bone involvement. 3, 4
- Two-day regimens are as effective as five-day regimens for simple contaminated wounds 6
- Start antibiotics immediately, as delays beyond 3 hours significantly increase infection risk 4, 5
Special Circumstances
For obstetrical anal sphincter injuries (third- and fourth-degree perineal lacerations): 3
- A second- or third-generation cephalosporin should be administered 3
- Add metronidazole with consideration of gentamicin (or clindamycin in penicillin allergy) for adequate vaginal and bowel flora coverage 3
If MRSA is suspected based on local prevalence: 4
- Add trimethoprim-sulfamethoxazole 160-800 mg orally twice daily to the base regimen 4
For facial wounds: 3
- Manage with copious irrigation, cautious debridement, and preemptive antibiotics 3
- Primary closure is recommended for facial wounds despite contamination 3
Critical Adjunctive Management
Tetanus prophylaxis is mandatory: 3, 4, 5
- Administer tetanus toxoid if not current within 10 years 3
- Tdap is preferred over Td if not previously given 3, 5
Wound preparation is essential: 4, 5
- Thorough irrigation and debridement of devitalized tissue must be performed before antibiotic administration 4, 5
- Surgical-site preparation with povidone-iodine or chlorhexidine is reasonable 3
Common Pitfalls to Avoid
Do not use first-generation cephalosporins (like cephalexin) alone for contaminated wounds: 4
- They lack adequate anaerobic and gram-negative coverage 4
- Studies show cephalexin provides no benefit over placebo for simple abscesses after drainage 2
Avoid clindamycin monotherapy: 4
- Poor activity against environmental gram-negative organisms 4
Do not delay antibiotic initiation while awaiting culture results in contaminated wounds: 4
Follow-Up Assessment
Evaluate patients within 48-72 hours for signs of infection: 4, 5