**6.2. Efficacy of antibiotics in the prevention of bacteraemia secondary to dental procedures**

The majority of studies show that amoxicillin is effective in the control of bacteraemia of oral origin, reducing the rate of positive blood cultures after dental interventions in a range that varies between 70 and 100%. There are a number of reports on the efficacy of alternative antibiotics to amoxicillin for the prevention of bacteraemia of oral origin. Results are heterogeneous as they are conditioned by numerous factors such as geographical situation, previous patient oral health status, blood culture sampling technique, microbiological analysis, resistance maps, etc.; however, in general, alternative antibiotics show a lower efficacy in the control of bacteraemia.

Interestingly, clindamycin constitutes the alternative antibiotic of choice to amoxicillin in the three main guidelines (AHA, ESC and AIEPEG). Although some studies have concluded that clindamycin was useful to reduce oral bacteraemia, more recently published studies have found that clindamycin prophylaxis does not produce a significant reduction in the incidence of oral bacteraemia during dental procedures [15, 28, 29]. Some authors have proposed moxifloxacin as an alternative to amoxicillin, given its efficacy in experimental endocarditis [30] and in the prevention of bacteraemia following dental procedures in humans [15]. However, endocarditis expert committees appear to be ignoring this antibiotic at the present time.

*S. aureus* is now the most common pathogen in IE. This circumstance could justify the use of amoxicillin in association with a β-lactamase inhibitor, such as clavulanate, to broaden the bactericidal spectrum of antibiotic prophylaxis against IE. A recent study suggests that intravenous amoxicillin/clavulanate could be effective in the prevention of oral bacteraemia, virtually eliminating post-procedure inocula [29]. This observation opens the door to further research into the efficacy of oral amoxicillin/clavulanate in the prevention of bacteraemia. In any case, given its unusual demonstrated effectiveness in the elimination of oral bacteraemia, the intravenous prophylactic regimen of amoxicillin/clavulanate could be a high-efficacy alternative for patients with cardiac risk factors and severe systemic alterations, such as immune compromise, who require curative interventional dental treatment.
