Effect of rifampicin & isoniazid on the steady state pharmacokinetics of moxifloxacin.

Background & objectives: Moxifloxacin (MFX) is reported to have promising antimycobacterial activity, and has a potential to shorten tuberculosis (TB) treatment. We undertook this study to examine the influence of rifampicin (RMP) and isoniazid (INH) on the steady state pharmacokinetics of MFX individually in healthy individuals. Methods: A baseline pharmacokinetic study of MFX (400 mg once daily) was conducted in 36 healthy adults and repeated after one week of daily MFX with either RMP (450/600 mg) (n = 18) or INH (300 mg) (n = 18). Plasma MFX concentrations were determined by a validated HPLC method. Results: Plasma peak concentration and exposure of MFX was significantly lower and plasma clearance significantly higher when combined with RMP (P<0.001). The Cmax to MIC and AUC0-12 to MIC ratios of MFX were significantly lower during concomitant RMP (P<0.001). INH had no significant effect on the pharmacokinetics of MFX. Interpretation & conclusions: Concomitant RMP administration caused a significant decrease in Cmax and AUC0-12 of MFX, the mean decreases being 26 and 29 per cent, respectively. It is uncertain whether this decrease would affect the treatment efficacy of MFX. Prospective studies in TB patients are needed to correlate MFX pharmacokinetics with treatment outcomes.

Infective endocarditis due to Acinetobacter baumannii complex--a case report.

We report a case of infective endocarditis caused by Acinetobacter baumannii complex in a 27-year-old male patient. The patient presented with fever of five days duration, palpitation, dyspnea, cough and chest pain. He had undergone a surgical repair of ruptured aneurysm of sinus of valsalva a month before. The transthoracic echocardiogram revealed a large vegetation on the aortic valve. Three samples of blood for culture grew gram-negative pleomorphic coccobacilli within 24 hours which were identified by cultural and biochemical characteristics to be Acinetobacter baumannii complex. Antimicrobial susceptibility was performed by Kirby-Bauer method and the isolate were found to be resistant to ampicillin, Ciprofloxacin, Ceftriaxone, Gentamicin, Amikacin, Augmentin, Levofloxacin, Piperacillin-Tazobactam, Netilimicin and sensitive to Imipenem. Patient was initially treated with Ceftraixone and Gentamicin and subsequently with Ampicillin and Amikacin but did not respond to treatment and died of sepsis before therapy with Imipenem could be started.