Foscarnet for treatment of cytomegalovirus infections in bone marrow transplant recipients

Abstract

42 episodes of verified or clinically suspected cytomegalovirus (CMV) infection in 40 bone marrow transplant (BMT) recipients were treated with foscarnet (trisodium phosphonophormate hexahydrate). CMV infection was verified in 31/42 treatment episodes. Symptoms treated were pneumonia (n = 17), pancytopenia with or without fever (n = 12), enteritis (n = 5), fever (n = 4), encephalitis (n = 2), retinitis (n = 1) and hepatitis (n = 1). Foscarnet was given as a continuous intravenous infusion. Side-effects observed were increase in serum creatinine (38%), decrease in serum calcium (19%), increase in serum bilirubin (12%), decrease in hemoglobin concentration (7%), increase in serum calcium (5%), increase in serum transaminase (5%), hypophosphatemia (2%) and tremor (2%). CMV was eradicated from blood and/or urine in 11/25 (44%) of assessable treatment episodes with infection verified by isolation. Overall clinical improvements including eradication of CMV, afebrility and/or improvements in laboratory abnormalities were seen in 14/31 (45%) episodes of verified infection. All 15 patients with CMV interstitial pneumonia (CMV IP) died. We conclude that foscarnet is nephrotoxic but otherwise well tolerated with moderate clinical and virostatic effects on CMV infection. The effect on CMV IP is discouraging.