A number of studies have now confirmed the value of antibiotic therapy in moderate-to-severe AECB (26-28). Guidelines for the use of antibiotics have been proposed by various groups in Canada, Europe, Latin America and the Asia Pacific region (29-32). Fluoroquinolones have a major role in these guidelines, notably among patients with risk factors for poor outcome (33), and they are drugs of choice in these sorts of patients (34-37).

A number of studies have evaluated levofloxacin in AECBs of varying severity (9, 18,19). In comparison with cefaclor, in mild-to-moderate exacerbations, cure rates of 92% were obtained in either group. Masterton (19) reported cure rates at 7-10-days post-treatment of 83% and 85% in per-protocol groups receiving levofloxacin 500 mg o.d. for 5 and 7 days, respectively. Shah (9) recorded a 79% overall response rate after treatment with levofloxacin 500 mg o.d. for 7-10 days, superior to that after cefuroxime axetil 250 mg b.i.d. (66%): in more severely ill patients, the cure rates were 75% and 63%, respectively. Therefore, levofloxacin offers an effective alternative to oral cephalosporins, notably in terms of eradication of H. influenzae, persistence of which appears to be associated with earlier relapse and therefore a shorter infection free interval between AECBs.