Objectives: To evaluate by a prospective randomized controlled study the efficacy of the association of potassium citrate and dry extract of couch grass (Agropyrum repens) (CalcoMEV) in renal stone treatment.
Materials and methods: 50 patients with nephrolithiasis associated with one or more active metabolic alterations that constitute an indication to the use of potassium citrate were randomly divided in two equal unblinded treatment groups. A group of patients was assigned to treatment with the association of potassium citrate and couch grass (at the dose of 24 mEq of potassium citrate and 100 mg of dry extract of Agropyrum repens bis in die) and the other group to potassium citrate (at a dose of 20 mEq ter in die). Each form of main treatment was associated, depending on the results of metabolic basal assessment, to allopurinol and/or an association of amiloride and hydrochlorothiazide and/or pyridoxine. Patients of both groups were advised the same diet based on a reduced intake of sodium, foods rich in oxalate and protein of animal origin, a normalized intake of calcium and an increase in fluid intake (> 2 liters every day).
Results: At the end of the 5-month follow-up period, the group treated with the association of potassium citrate and couch grass showed a significant reduction in the total number of stones (-1.0 +/- 0.2 vs. 0.0 +/- 0.2 stones) and in the larger diameter of the stones (-3.6 +/- 0.9 mm vs. 0.0 +/- 0.8 mm), as well as a statistically significant reduction of uric acid urinary excretion (-164.7 +/- 45.3 vs -38 +/- 42 mg/24 h). No significant differences in the two groups were observed with respect to urinary citrate, oxalate and calcium urinary excretions and urinary pH.
Conclusions: This prospective randomized study demonstrates the superiority of the association of potassium citrate and dry extract of couch grass, in combination with standard pharmacological and dietary treatment, in reducing the number and size of urinary stones with respect to potassium citrate in association with the same pharmacological and dietary regimen.