Correlation of serum ofloxacin concentration and serum creatinine level in patients on prolonged therapy

Serum ofloxacin concentrations were assessed by high performance liquid chromatography 4 h after drug administration in 86 patients with pulmonary tuberculosis. All patients had multidose, once-daily drug administration (200 mg to 800 mg p.o.) for at least 3 weeks prior to assessment. The serum creatinine levels were simultaneously assessed for these patients. A positive correlation was found between serum ofloxacin (Y) and serum creatinine x dose of ofloxacin administered/body surface area (X). The correlation can be represented mathematically by the equation: Y = 0.87X + 0.68 (r = 0.80, p < 0.001).