[Cardiac tolerance of moxifloxacin: Clinical experience from a large observational French study in usual medical...

Moxifloxacin (Izilox) is prescribed for bacterial respiratory tract infections. ECG analysis done in clinical trials showed a mean QT prolongation at 6 ms that could lead to Torsades de Pointe. However, Izilox was well tolerated during clinical trials. To confirm the correct safety profile of Izilox in a large sample of patients, a French PMS study - MMEDIAT - was carried out in usual medical practice.

This prospective observational uncontrolled and monitored study was conducted in 13,578 patients with respiratory tract infection and treated with moxifloxacin 400 mg daily (duration: 5 to 10 days in accordance to the Market Authorization). Any clinical event being potentially a surrogate of a ventricular rhythm disorder ("critical event") were collected and analyzed by a Scientific Committee in charge to determine the potential cardiac origin of the reported event and to establish a causal relationship with the treatment.

Among 13,578 patients, 1046 adverse events (678 patients [5%]) were reported, including 854 drug related events (564 patients [4.15%]). Of these 1046 adverse events, 95 (62 patients [0.46%]) were serious. A total of 189 critical adverse events (159 patients [1.2%]) were reviewed by the Scientific Committee. After analysis, 34 adverse events (28 patients [0.21%]) were assessed from potential cardiac origin. Of these 34 adverse events, 25 (19 patients [0.14%]) were assessed as drug-related: palpitations [13 patients], tachycardia [4 patients], malaise [4 patients], vertigo [3 patients] and pallor [1 patient]. All adverse events were transient and had favourable outcome.

This PMS study confirmed that Izilox is well-tolerated in usual medical practice, in adequation with the safety data obtained in clinical trials.