From the Guidelines
Haemophilus influenzae is generally not susceptible to clindamycin, making it an inappropriate choice for treating H. influenzae infections. Clindamycin has poor activity against most Gram-negative organisms, including H. influenzae, due to limited penetration through their outer cell membrane 1. For H. influenzae infections, preferred antibiotics include beta-lactams (such as amoxicillin-clavulanate, ceftriaxone, or cefotaxime), fluoroquinolones (like levofloxacin or ciprofloxacin), or macrolides (such as azithromycin) 1. The choice depends on the infection site, severity, and local resistance patterns. Beta-lactamase production is common in H. influenzae, so beta-lactamase-stable antibiotics or combination therapies are often necessary. When treating suspected H. influenzae infections empirically, it's essential to select an antibiotic with known activity against this organism rather than clindamycin, which would likely result in treatment failure.
Some key points to consider when treating H. influenzae infections include:
- The use of amoxicillin-clavulanate, ceftriaxone, or cefotaxime as preferred antibiotics 1
- The consideration of fluoroquinolones or macrolides as alternative options 1
- The importance of selecting an antibiotic with known activity against H. influenzae to avoid treatment failure
- The need to consider local resistance patterns and the severity of the infection when choosing an antibiotic
It's also important to note that clindamycin is not recommended for the treatment of H. influenzae infections, as it has poor activity against this organism 1. Instead, antibiotics with known activity against H. influenzae should be used to ensure effective treatment and minimize the risk of treatment failure.
From the Research
Susceptibility of Haemophilus influenzae to Clindamycin
- The susceptibility of Haemophilus influenzae to Clindamycin has been studied in several research papers 2, 3, 4, 5, 6.
- According to a study published in 1974, the minimum inhibitory concentrations (MICs) of Clindamycin for H. influenzae ranged from 2 to 16 μg/ml 3.
- Another study published in 2004 found that 90.6% of H. influenzae isolates were susceptible to Clindamycin 4.
- A study published in 2011 found that 11.1% of H. influenzae isolates were resistant to Clindamycin 5.
- However, a more recent study published in 2022 did not provide specific information on the susceptibility of H. influenzae to Clindamycin 6.
Resistance Mechanisms
- The resistance mechanisms of H. influenzae to Clindamycin are not well understood, but it is known that β-lactamase production is a common mechanism of resistance to other antibiotics 6.
- The 2022 study found that 28.1% of H. influenzae isolates were resistant to ampicillin, and that this resistance was predominantly associated with the detection of a β-lactamase gene 6.