Background: Ramipril administered once daily is characterized by an attenuation of its pharmacological activity in the following 24 hours, whose effects on antiproteinuric activity have not yet been investigated.
Methods: The antiproteinuric efficacy of Ramipril has been evaluated in a cross-over study in 20 patients with renal disease, proteinuria and hypertension (GFR50 mL / min, proteinuria <3 g / day; SBP/DBP 150/90 mmHg). Proteinuria was measured over 24 hours on three consecutive urine collections (morning, afternoon and night) in the absence of antiproteinuric drugs and after ten days of treatment with single morning administration of Ramipril 2.5 mg or Ramipril 10 mg.
Results: At baseline: mean proteinuria was not significantlychanged over the course of the three urinary collections (88 7.2 mg/h in the morning of 80 10.5 mg/h in the afternoon and 81 10.1 mg/hr during the night). After Ramipril 2.5 mg/day: slight reduction in mean proteinuria, with no significant differences between collections (80 11 mg/h in the morning, 69 7.4 mg/h in the afternoon and 75 9.1 mg/h during the night). After Ramipril 10 mg/day: afternoon and night values of proteinuria were significantly reduced compared to baseline; noctural proteinuria was significantly lower than morning value (51 7.5 mg/h vs. 81 10 mg/h, p <0.05).
Conclusion: The antiproteinuric effectiveness of Ramipril tends to decrease significantly over the 24hours after a single daily administration. An increase and/or division of Ramipril dose might help to stabilize and to maximizeits antiproteinuric effectiveness.