Erythrocytosis occurs in 10-15% of renal transplant recipients and the
re is evidence that the production of erythropoietin is modulated by a
denosine. We prospectively evaluated the effects of theophylline, a no
nselective adenosine antagonist, in 8 patients with erythrocytosis aft
er renal transplantation. All patients were given triple-drug immunosu
ppressive therapy with methylprednisolone (8 mg/daily), azathioprine (
2 mg/kg b.w. daily) and cyclosporin A (4 mg/kg b.w. daily), After an 8
-week course of theophylline treatment (Theodur 300 mg x 2 daily), the
mean serum erythropoietin levels were significantly reduced (from 61
mIU/ml before to 16.5 mIU/ml after treatment, p < 0.05). Also the hema
tocrit was reduced from 0.58 before to 0.50 after treatment (p < 0.05)
. The previous requirement of monthly phlebotomy was eliminated in all
transplant recipients. The above effects were reproducible when the p
atients were rechallenged with theophylline after a recovery period. I
t is suggested that theophylline modulates the production of erythropo
ietin as well as the hematocrit levels in patients with erythrocytosis
after renal transplantation and may be useful in the treatment of thi
s condition.