Effect of losartan on haemoglobin concentration in renal transplant recipients--a retrospective analysis.

PURPOSE OF STUDY To evaluate the effect of the angiotensin II type 1 receptor antagonist, losartan, on post-transplant erythrocytosis. METHODS We retrospectively analyzed the influence of losartan therapy on haemoglobin levels of renal transplant recipients. Twenty-eight patients who received losartan therapy to control hypertension were divided into two groups. In 10 patients, losartan therapy was initiated after treatment with ACE inhibitors which was discontinued due to adverse reactions (Group A). Group B consisted of 18 patients treated with losartan who had never received ACE inhibitors. RESULTS There was no difference in mean haemoglobin concentration and haematocrit between the two groups before the onset of losartan therapy. In Group B, mean haemoglobin concentration and haematocrit decreased from 137 +/- 20 g/l and 0.4 at the start of losartan therapy to 120 +/- 16 g/l (P < 0.0005) and 0.35 (P < 0.0005), respectively 3 months later. In Group A, neither haemoglobin nor haematocrit differed between the onset of losartan therapy and the end of the study. Serum creatinine increased from 158 mumol/l +/- 78 to 172 mumol/l +/- 80 in Group B (P < 0.005), but remained stable in Group A. Plasma protein concentrations remained stable in each group and there was no change in diuretic therapy during the study. CONCLUSION Our study suggests that losartan therapy decreases haemoglobin in renal transplant recipients.