Methods: We collected data on all patients treated with FOS from 5/2011–5/2015, including demographics, clinical indication, adverse events, nephrotoxicity, as defined by the RIFLE criteria (risk, injury, failure, loss, end-stage kidney disease), and outcomes at BWH/DFCI.
Results: 63 patients received FOS for treatment of HHV diseases. Median age was 58 years (range, 21-75) and 39 (62%) were male. 56 (89%) had an underlying malignancy, of these 51 (81%) had underdone SCT. Among the remaining patients; 4 (6%) had received a SOT, and 3 (5%) had HIV. FOS was used for HHV6 encephalitis (20, 32%), resistant CMV (19, 30%), resistant HSV (8, 13%), resistant VZV (5, 8%), and empirically for suspected HHV infections in (11, 17%). The median initial and final daily FOS doses were 131 (range, 33.6-180) mg/kg/day and 125 (range, 35-180) mg/kg/day, respectively. The median duration of therapy was 7 days (IQR, 4-15; range, 0-96). Nephrotoxicity was observed in 20 (31.7%) patients; the median time to onset of nephrotoxicity was 8.5 days (IQR, 5.5-15; range, 1-54). According to RIFLE criteria 5 (7.9%) developed risk, 12 (19%) had failure, and 3 (4.8%) exhibited loss of renal function. 62 (98%) patients were on ≥1 concomitantly administered nephrotoxic agent. The risk of FOS-associated nephrotoxicity was lower in SCT patients (OR 0.64; 95%CI, 0.17–2.33). The most frequent electrolyte disturbance requiring repletion was hypocalcemia 58 (92%). Blood viral clearance was observed in 45 (71%) patients. All cause in-hospital mortality was observed in 11 (17%).
Conclusion: The incidence of foscarnet-associated nephrotoxicity may be higher than previously reported in immunocompromised patients; this agent should be used with caution for treatment of resistant HHV infections.
A. Mcdonnell, Clarion Health Care: Consultant , Consulting fee
F. M. Marty, None