Abstract: The Authors report on the use of linezolid for the treatment of three patients with osteomyelitis. All three patients had post-traumatic multisensitive hand bone methicillin-susceptible Staphylococcus aureus osteomyelitis, which did not respond to antimicrobial regimens including drugs in vitro active against the isolated strains. Clinical cure and microbiologic eradication was obtained with oral linezolid in all three patients. Linezolid was well tolerated. Mild thrombocytopenia was observed in one patient at the end of the third week of treatment and it was promptly resolved after the discontinuation of linezolid. Linezolid minimum inhibitory concentrations (MICs) consisted of 2 mg/l for all three S. aureus isolates while the bactericidal activity in vitro was not present up to the linezolid concentration of 32 mg/l. In spite of a lack of in vitro bactericidal activity, linezolid was effective in curing the patients and eradicating the infection. Trough and peak plasma concentrations of linezolid were above the MICs of the isolates. These values ranged from 3.93 to 14.95 mg/l at trough and 5.03 to 25.91 mg/l at peak. The oral bioavailability, pharmacokinetic profile and antibacterial spectrum of linezolid make this oxazolidonone antimicrobial an attractive drug for the treatment of chronic osteomyelitis. Prolonged administration requires careful surveillance for side effects, until these complications are better understood.
Abstract: Organ transplant recipients are at increased risk for severe invasive aspergillosis, and amphotericin deoxycholate has been the standard treatment for many years. Currently, however, lipid formulations are preferred due to their few side effects. Also, a number of new antifungal drugs have been developed including new azoles and echinocandins. Caspofungin is the first of the echinocandin derivatives patented to treat patients with invasive aspergillosis who are refractory or intolerant to other therapies. A renal transplant patient on immunosuppressive treatment with chronic hepatitis B virus infection was admitted with fever, hemophthisis and lung consolidation, diagnosed to be probably caused by Aspergillus flavus. The patient developed cholestatic hepatitis most likely related to itraconazole. Clinical failure and in vitro itraconazole resistance of the isolate was also documented while the patient was receiving itraconazole at a reduced dosage. Caspofungin was administered once a day as ambulatory treatment and was well tolerated. Clinical improvement was observed after 6 weeks of treatment and no hepatic toxicity was documented. Caspofungin seems to be a potentially useful antifungal agent in renal transplant patients with invasive aspergillosis. Further evaluation of the efficacy of caspofungin is needed.
