Cyclosporine trough levels and its side effects in kidney transplant recipients.

INTRODUCTION: Cyclosporine is the backbone of immunosuppression in kidney transplantation. However, it is associated with side effects, some of which are dose-dependent. We evaluated association between cyclosporine trough level and its side effects. MATERIALS AND METHODS: In 50 kidney transplant recipients, serum cyclosporine level, fasting blood glucose, and serum creatinine were measured 7 times during first 6 months after transplantation. The participants were also assessed for blood pressure, hand tremor, and headache at each visit. The relationship between cyclosporine trough level and hypertension, hyperglycemia, hand tremor, and headache were evaluated. RESULTS: There were no significant relationship between cyclosporine levels and allograft function. Except at the second week and sixth month, there were no significant differences between drug doses in various serum cyclosporine trough level groups. At the second week, the mean drug dose in patients with cyclosporine trough levels less than the target therapeutic level was 279.16 +/- 56.23 mg/d, while in the patients with cyclosporine levels higher than the therapeutic level, its dose was 302.08 +/- 66.61 mg/d (P < .05). At the sixth month, the mean drug dose was 137.50 +/- 17.67 mg/d in the patients with lower than target cyclosporine levels, and it was 242.18 +/- 58.25 mg/d in those with cyclosporine levels higher than the therapeutic level (P < .05). There was no significant relationship between serum cyclosporine level and its side effects. CONCLUSIONS: We demonstrated cyclosporine trough level had no direct relation with drug side effects and it is not a suitable measure for assessment of drug side effects.