Stability and compatibility of ceftazidime administered by continuous infusion to intensive care patients

The stability and compatibility of ceftazidime have been examined in the context of its potential use in concentrated solutions for continuous infusion in patients suffering from severe nosocomial pneumonia and receiving other intravenous medications by the same route. Ceftazidime stability in 4 to 12 % solutions was found satisfactory (<10 % degradation) for 24 h if kept at a temperature of 25°C (77°F) maximum. Studies mimicking the simultaneous administration of ceftazidime and other drugs as done in clinics showed physical incompatibilities with vancomycin, nicardipine, midazolam, and propofol and a chemical incompatibility with N-acetylcystein. Concentrated solutions (50 mg/ml) of erythromycin or clarithromycin caused the appearance of a precipitate, whereas gentamicin, tobramycin, amikacin, isepamicin, fluconazole, ketamine, sufentanil, valproic acid, furosemide, uradipil, and a standard amino acid solution were physically and chemically compatible. In their original review, Craig and Ebert (7) pointed out to the many potential advantages of the administration of b-lac-tams by continuous infusion (optimization of outcome based on their pharmacodynamic properties [time-dependent antibi-otics {5, 6}] as well as pharmacoeconomic advantages [de