Failure of oral antibiotic therapy after bariatric surgery
Roy et al. investigated the association between the history of RYGB and increased treatment failure in patients who received oral antibiotics53. Treatment failure was defined as any prescription change that resulted in an increased daily dose, frequency or duration of current oral antibiotics, substitution or addition of another oral, intramuscular, or intravenous antibiotic for the same indication, any surgical intervention for current infection, emergency room or outpatient visit for current infection and hospitalization for current infection. In their study, 186 patients were included (58 RYGB patients and 128 controls). There was no significant difference in composite therapeutic failure rates by time since RYGB surgery (24.1%, n=14) compared to the control group (15.6% n=20). However, in the subgroup treated with fluoroquinolones (31.6 vs. 7.1 %, n= 6 and 2 respectively) and with sulfamethoxazole/trimethoprim (40 vs. 7.1%, n=4 and 2 respectively) more therapeutic failure rates were reported compared to controls.
Summarizing, for beta-lactam antibiotics, similar, increased or decreased exposure can be anticipated after surgery, however as concentrations seem overall high enough, these antibiotics can generally be applied. For macrolide antibiotics, a reduced exposure up to 30-40% after surgery has been reported and therefore the use of these antibiotics should be discouraged. While fluoroquinolones did show some reduction in exposure after surgery, the overall bioavailability seems adequate. In general, it seems that bariatric surgery patients treated with oral antibiotics should be monitored closely for therapy failure and side effects. When prescribing antibiotics to bariatric surgery patients, several factors should be considered including , the site and severity of infection, route of administration and potential toxicity.