Doxycycline for Tracheostomy Site Infection
Recommended Dosing and Duration
For a suspected tracheostomy site infection in adults, doxycycline 100 mg orally or IV twice daily should be administered, but this is NOT the optimal antibiotic choice for this indication. 1
Critical Limitation: Doxycycline is Inadequate for Tracheostomy Site Infections
Doxycycline monotherapy should NOT be used as first-line treatment for tracheostomy site infections because these infections are predominantly polymicrobial with mixed aerobic-anaerobic flora that doxycycline does not adequately cover. 2
Microbiology of Tracheostomy Site Infections
76% of tracheostomy site wound infections involve mixed aerobic and anaerobic bacteria, with an average of 5.8 isolates per specimen (2.9 aerobes and 2.9 anaerobes). 2
The most common pathogens include Peptostreptococcus species, Bacteroides species, alpha-hemolytic streptococci, Fusobacterium species, and Pseudomonas aeruginosa. 2
72% of tracheostomy site infections harbor beta-lactamase-producing bacteria, including all Staphylococcus aureus and Bacteroides fragilis group isolates. 2
Appropriate Antibiotic Selection
For fulminant tracheostomy site infections, piperacillin/tazobactam, 3rd generation cephalosporins, or carbapenems are recommended to provide adequate coverage against the gram-negative facultative anaerobic biofilm and polymicrobial flora. 3
Treatment Duration
Duration should be approximately 7 days, depending on clinical response and severity of infection. 4
Deep incisional surgical site infections significantly prolong ventilator dependency (mean 3.92 days, p=0.045), emphasizing the importance of appropriate antibiotic selection. 3
If Doxycycline Must Be Used
If clinical circumstances require doxycycline use despite its limitations:
- Adults: 100 mg orally or IV every 12 hours 1
- Children >8 years and >100 lbs: 100 mg every 12 hours 1
- Children >8 years and ≤100 lbs: 2 mg/lb divided into two doses 1
The therapeutic antibacterial serum activity persists for 24 hours following recommended dosage. 1
Key Clinical Pitfalls
Do not use doxycycline monotherapy for tracheostomy site infections – the polymicrobial nature and presence of beta-lactamase producers make it inadequate. 2
Administer with adequate fluids to reduce risk of esophageal irritation and ulceration. 1
If gastric irritation occurs, give with food or milk – absorption is not markedly affected. 1
Consider risk factors for infection: neck dissection (especially multi-level), smoking, and previous neck irradiation significantly increase infection risk. 3, 5