Moxonidine treatment of hypertensive patients with advanced renal failure

OBJECTIVES: To compare safety and tolerability of moxonidine versus nitrendipine in hypertensive patients with renal failure. A secondary endpoint was to test whether the sympatholytic drug moxonidine slows decline of renal function when added to standard therapy with an angiotensin-converting enzyme inhibitor or AT(1) receptor antagonist plus loop diuretic. DESIGN: This prospective, randomized, double-blind, multicenter study recruited 177 patients with advanced renal failure receiving antihypertensive standard therapy at outpatient clinics in Germany and Hungary. Following a 2 week run-in, patients were randomized to 24 weeks of add-on treatment with 0.3 mg/day moxonidine or 20 mg/day nitrendipine. RESULTS: The incidence of pre-defined specific adverse events was 42% in the moxonidine (37/89 patients) and 46% in the nitrendipine group (38/82 patients) in intention-to-treat analysis. Intensity and multiplicity were comparable. The dropout rate due to adverse events was 12.4% in the moxonidine and 9.8% in the nitrendipine group. Creatinine clearance according to Cockcroft and Gault decreased by 0.5 +/- 4.3 ml/min (mean +/- standard deviation) in the moxonidine group and 2.3 +/- 4.0 ml/min in the nitrendipine group. Serum creatinine increased by 12.7 +/- 49.2 micromol/l in the moxonidine group and by 43.4 +/- 71.3 micromol/l in the nitrendipine group. These differences were statistically significant (P < 0.05). CONCLUSION: Add-on treatment with 0.3 mg/day moxonidine in hypertensive patients with renal failure is well tolerated and not inferior to 20 mg/day nitrendipine with respect to the incidence of specific adverse events. The idea of a sympatholytic drug to be renoprotective is appealing but needs further evaluation.