Literature reports suggest variable reductions in ciprofloxacin bioavailability when administered nasogastrically (NG) with continuous enteral feeds in ICU patients. This study investigates the pharmacokinetic characteristics of ciprofloxacin suspension administered NG in ICU patients receiving continuous enteral nutrition.
In this randomized, prospective, multi-centre, single crossover study, patients were enrolled if they were stable, critically ill, at least 18 years old, had an arterial line, were tolerating continuous enteral feeds administered NG (at least 40 ml/h) for a minimum of 24 hours. Patients were randomly assigned to receive one dose of ciprofloxacin 400 mg IV or ciprofloxacin 1000 mg oral suspension NG with a 48 hour washout between each cross-over period. Serial blood samples were collected after each dose and analyzed by HPLC.
From Apr. 2000 to Feb. 2002, patients were screened and a total of 12 patients completed both arms of the study. The mean ± SD age was 58 ± 14.5 years and weight was 80.1 ± 26.7 kg. Mean Cmax values for the IV route and NG route respectively were 2.62 ± 1.12 mg/ L and 1.29 ± 0.73 mg/ L respectively (p<0.005). Corresponding mean AUC values for the 400mg IV dose and 1000mg NG dose respectively were 11.7 ± 4.9 mg*h/L and 11.2 ± 5.6 mg*h/L (p > 0.4), suggesting that the NG dose may be comparable to the IV dose in terms of AUC. On average, only 39% of the 1000 mg NG dose was absorbed [mean absolute bioavailability of ciprofloxacin suspension was 39.25 ± 16.6% [range: 11.9 –61.9; 95% CI: 28.7 –49.8%, standard oral dose bioavailability 80%)].
Findings demonstrate a reduced mean Cmax and absolute bioavailability when 1000 mg of ciprofloxacin suspension is administered concomitantly with continuous enteral feeding through a NG tube in comparison to a 400 mg IV dose.
The degree of inter-patient variability along with considerable, unpredictable and inconsistent absorption in ICU patients, makes the use of ciprofloxacin suspension administered NG unreliable.
O. Fernandes, Bayer - covered cost of study drug supply/assay