From the Guidelines
Doxycycline is not recommended as a first-line treatment for Haemophilus influenzae infections. According to the most recent guidelines, amoxicillin and ampicillin should be used only when susceptibility is known, and alternative antibiotics such as second or third generation cephalosporins or fluoroquinolones are recommended for treatment of b-lactamase producing H. influenzae 1. The guidelines do not mention doxycycline as a recommended treatment option for H. influenzae infections.
Key Points to Consider
- The guidelines recommend using amoxicillin and ampicillin only when susceptibility is known, due to high rates of b-lactamase production in non-typeable strains of H. influenzae 1.
- Second or third generation cephalosporins or fluoroquinolones are recommended for treatment of b-lactamase producing H. influenzae 1.
- Doxycycline is not mentioned as a recommended treatment option for H. influenzae infections in the guidelines.
Alternative Treatment Options
- Amoxicillin-clavulanate
- Cephalosporins (e.g. cefuroxime, cefixime, cefpodoxime, cefotaxime)
- Fluoroquinolones (e.g. levofloxacin, although resistance rates are increasing in some regions) 1
From the FDA Drug Label
Respiratory tract infections caused by Haemophilus influenzae. Doxycycline is indicated for the treatment of respiratory tract infections caused by Haemophilus influenzae, when bacteriologic testing indicates appropriate susceptibility to the drug.
- The drug is effective against Haemophilus influenzae in respiratory tract infections.
- Key points:
- Doxycycline is used to treat infections caused by susceptible bacteria.
- Bacteriologic testing is recommended to ensure the bacteria are susceptible to the drug.
- The drug is effective in treating respiratory tract infections caused by Haemophilus influenzae 2
From the Research
Effectiveness of Doxycycline in Treating Haemophilus influenzae Infections
- Doxycycline is effective in treating Haemophilus influenzae infections, as shown in several studies 3, 4, 5, 6, 7.
- The level of resistance to doxycycline in H. influenzae is very low (less than 1%) and has not changed significantly over the past ten years, making doxycycline a suitable antibiotic for instance in the treatment of chronic bronchitis when H. influenzae is involved 4.
- The antibiotic susceptibility of H. influenzae strains isolated from respiratory specimens of patients admitted to the pulmonology services between 2005 and 2010 was assessed, and the prevalence of antibiotic resistance to doxycycline was stable over the 6-y period 5.
- US invasive H. influenzae isolates remain predominantly susceptible to clinically relevant antibiotics except ampicillin, and doxycycline is not mentioned as a resistant antibiotic in this study 7.
- The mechanisms of resistance to major antibiotics, including doxycycline, are reviewed, and the consequences of antibiotic resistance for the treatment of diseases caused by H. influenzae are discussed 6.
Key Findings
- Doxycycline is effective against H. influenzae, with low resistance rates 4, 5.
- The stability of doxycycline susceptibility over time is an important factor in its use for treating H. influenzae infections 5.
- The suitability of doxycycline for treating chronic bronchitis when H. influenzae is involved is supported by its low resistance rate 4.