The role of cyclosporine dosage and plasma levels in efficacy and toxicity in bone marrow transplant recipients.

The efficacy and toxicity of cyclosporine (CsA) treatment for graft-versus-host disease (GVHD) was studied in 53 bone marrow transplant recipients. No correlation was found between acute or chronic GVHD and CsA dosage (daily or cumulative) or CsA plasma levels. Acute nephrotoxicity developed in 63% of the patients. Patients with nephrotoxicity had significantly higher CsA plasma levels during the first month after transplantation compared with patients without nephrotoxicity (P less than 0.05) although the cumulative CsA doses did not differ. Children had significantly fewer episodes of nephrotoxicity compared with adults (P less than 0.01). In spite of this, children received a significantly higher cumulative CsA dose (P less than 0.001). However, CsA plasma levels did not differ between children and adults, suggesting a difference in availability or elimination of the drug. Hypertension developed in 28% of the patients. Hypertensive patients tended to be younger compared with normotensive patients (P = 0.07). Nephrotoxicity tended to be less common in patients with hypertension (P = 0.06). No correlation existed between hypertension and CsA dose or CsA plasma levels. In conclusion, no correlation was found between CsA dose and GVHD or CsA toxicity, and in the single patient CsA plasma levels were of no value in predicting side effects of CsA treatment.