Therapeutic efficacy of amoxicillin and rifaximin in patients with small intestinal bacterial overgrowth and infection.

Introduction: Small intestinal bacterial overgrowth (SIBO) may coexist with infection, which can be the cause of chronic gastrointestinal complaints.

Aim: Evaluation of the therapeutic efficacy of amoxicillin and rifaximin in the treatment of these diseases.

Material And Methods: The lactulose hydrogen breath test (LHBT) and the urea breath test (C-UBT) were performed in 116 patients. In 62 patients the coexistence of small intestinal bacterial overgrowth and infection was observed. Then, in group I ( = 30) pantoprazole (2 × 40 mg), amoxicillin (2 × 1000 mg) and metronidazole (2 × 500 mg) and in group II ( = 32) pantoprazole and amoxicillin at the above doses and rifaximin (3 × 400 mg) were administered for 10 days. After 6 weeks, both breath tests were repeated and the degree of remission of symptoms was measured using a 10-point visual analog scale (VAS).

Results: After the treatment the LHBT index decreased in group I from 61.2 ±19.4 ppm to 22.0 ±8.2 ppm ( < 0.001) and in group II from 59.6 ±15.5 ppm to 15.2 ±8.6 ppm ( < 0.001). Eradication of (C-UBT below 4.0‰) was achieved in 63.3% of patients in group I and 59.4% in group II ( > 0.05). The decrease of pain below 3.0 points in the VAS was obtained in 64.8% of patients in group I and in 56.2% in group II.

Conclusions: Combination of amoxicillin and rifaximin may be effective in the treatment of patients with small intestinal bacterial overgrowth syndrome and concomitant infection.