Effect of Roux-en-Y gastric surgery on ciprofloxacin pharmacokinetics: an obvious effect?

To evaluate pharmacokinetic parameters of ciprofloxacin in patients undergoing Roux-en-Y gastric surgery (RYGS).

Controlled, single-dose, open-label study in patients undergoing RYGS. Healthy overweight/obese patients 18-60 years old were included. The assessment was performed once in control patients and three times in case patients (before surgery and 1 and 6 months after surgery). In each visit, the subjects received a single oral dose of ciprofloxacin 500 mg. Venous blood samples were obtained at baseline and 0.5, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 8 and 14 h after ciprofloxacin intake. Pre- and post-surgery variables were compared using paired ANOVA or the Wilcoxon tests and control vs cases using ANOVA or Mann Whitney. Given the post-surgery change in body weight, the parameters were corrected by dose (mg)/body weight (kg). The analysis was performed using SPSS.

Ciprofloxacin C_max was significantly reduced 1 month after surgery (1840.9 ± 485.2 vs 1589.6 ± 321.8 ng/ml; p = 0.032) but not 6 months after. C_max on the sixth month was lower than C_max in control group (2160.4 ± 408.6 vs 1589.6 ± 321.8 ng/ml; p < 0.001). After correcting by the dose (mg)/patient's body weight, both C_max and AUClast showed significant decrease 1 and 6 months after surgery: C_max, 289.1 ± 65.3 and 263.5 ± 52.1 (ng/ml)/(dose (mg)/weight (kg)) respectively vs 429.3 ± 127.6 (ng/ml)/(dose (mg)/weight (kg)) at baseline; AUC, 1340.6 ± 243.0 and 1299.2 ± 415.4 (h × ng/ml)/(dose (mg)/weight (kg)) respectively vs 1896.7 ± 396.8 (h × ng/ml)/(dose (mg)/weight (kg)) at baseline. C_max 1 month post-surgery showed lower values than the control group (375.4 ± 77.4 vs 263.5 ± 52.1 ng/ml; p < 0.001).

Ciprofloxacin absorption is impaired 1 month and 6 months after RYGS. The effect on C_max and AUClast faded on the sixth month due to weight loss. It is no necessary to modify the doses of ciprofloxacin in these patients.