Gatifloxacin.

Gatifloxacin is a novel extended-spectrum fluoroquinolone with improved gram-positive and anaerobe coverage compared with older agents such as ciprofloxacin. It has good activity (but is slightly less active than ciprofloxacin) against Enterobacteriaceae. Gatifloxacin is generally 2- to 4-fold more active than ciprofloxacin against staphylococci, streptococci and enterococci and 4- to 16-fold more active than ciprofloxacin against anaerobes, including Clostridium and Bacteroides spp. In comparative clinical trials that included patients with lower respiratory tract, urinary tract, skin and soft tissue or gonococcal infections, clinical cure rates of > or = 89% were achieved with oral gatifloxacin 400 mg/day for 7 to 14 days. Data from a subset of North American patients included in a multinational trial showed that oral gatifloxacin 400 mg/day produced a significantly higher clinical cure rate than cefuroxime axetil 250 mg twice daily (89 vs 77%; p = 0.01) in patients with acute exacerbations of chronic bronchitis. The clinical efficacy of gatifloxacin was similar to that of clarithromycin or levofloxacin or ceftriaxone (with or without erythromycin) in the treatment of patients with community-acquired pneumonia. Oral gatifloxacin 400 mg/day showed clinical and bacteriological efficacy similar to that of levofloxacin in patients with skin and soft tissue infections. In patients with urinary tract infections, clinical cure and bacterial eradication rates achieved with a single 400 g oral dose of gatifloxacin were similar to those produced with ciprofloxacin. In a pooled analysis of tolerability data from trials that included 3021 patients treated with oral gatifloxacin 400 mg/day, the most commonly reported adverse events were nausea (8%), diarrhoea (4%), headache (4%) and dizziness (3%). The drug was reported to be well tolerated. Gatifloxacin does not appear to cause phototoxic effects.

Deferiprone: a review of its clinical potential in iron overload in beta-thalassaemia major and other transfusion-dependent diseases.

UNLABELLED: Patients with beta-thalassaemia and other transfusion-dependent diseases develop iron overload from chronic blood transfusions and require regular iron chelation to prevent potentially fatal iron-related complications. The only iron chelator currently widely available is deferoxamine, which is expensive and requires prolonged subcutaneous infusion 3 to 7 times per week or daily intramuscular injections. Moreover, some patients are unable to tolerate deferoxamine and compliance with the drug is poor in many patients. Deferiprone is the most extensively studied oral iron chelator to date. Non-comparative clinical studies mostly in patients with beta-thalassaemia have demonstrated that deferiprone 75 to 100 mg/kg/day can reduce iron burden in regularly transfused iron-overloaded patients. Serum ferritin levels are generally reduced in patients with very high pretreatment levels and are frequently maintained within an acceptable range in those who are already adequately chelated. Deferiprone is not effective in all patients (some of whom show increases in serum ferritin and/or liver iron content, particularly during long term therapy). This may reflect factors such as suboptimal dosage and/or severe degree of iron overload at baseline in some instances. Although few long term comparative data are available, deferiprone at the recommended dosage of 75 mg/kg/day appears to be less effective than deferoxamine; however, compliance is superior with deferiprone, which may partly compensate for this. Deferiprone has additive, or possibly synergistic, effects on iron excretion when combined with deferoxamine. The optimum dosage and long term efficacy of deferiprone, and its effects on survival and progression of iron-related organ damage, remain to be established. The most important adverse effects in deferiprone-treated patients are arthropathy and neutropenia/agranulocytosis. Other adverse events include gastrointestinal disturbances, ALT elevation, development of antinuclear antibodies and zinc deficiency. With deferiprone, adverse effects occur mostly in heavily iron-loaded patients, whereas with deferoxamine adverse effects occur predominantly when body iron burden is lower. CONCLUSION: Deferiprone is the most promising oral iron chelator under development at present. Further studies are required to determine the best way to use this new drug. Although it appears to be less effective than deferoxamine at the recommended dosage and there are concerns regarding its tolerability, it may nevertheless offer a therapeutic alternative in the management of patients unable or unwilling to receive the latter drug. Deferipone also shows promise as an adjunct to deferoxamine therapy in patients with insufficient response and may prove useful as a maintenance treatment to interpose between treatments.