Introduction. Frequent complications of kidney stone disease (KSD) are infectious and inflammatory processes in the organs of the genitourinary system, the most important of which is pyelonephritis. Adhering to a restrained tactic with small caliceal calculi, we observe a significant number of patients with chronic calculous non-obstructive pyelonephritis. Conservative treatment of these patients presents great practical difficulties, as it involves the mandatory parallel treatment of two diseases – pyelonephritis and KSD.

The aim of this prospective study was to investigate the effectiveness of conservative therapy in patients with chronic calculous pyelonephritis.

Materials and methods. The study included 100 patients with a verified diagnosis of chronic calculous pyelonephritis against the background of existing small caliceal calculi (up to 10 mm). Patients were divided into 2 groups, comparable in terms of the main evaluated criteria. Patients of the first (control) group (40 people) received etiotropic antibiotic course therapy in combination with antispasmodics and immunomodulators. Patients of the second (main) group (60 people) additionally for 3 months took the phytocomplex Onpelvicit 1 capsule 3 times a day under the control of urine pH.

Results. At the control examination after 3 months in the group of patients treated with Onpelvicit the frequency of exacerbations of chronic pyelonephritis was significantly lower than in the control group of patients. In the main group, 50% of patients showed a decrease in the size of the calculus, in 15% of cases – complete litholysis.

The noted positive effect in relation to chronic pyelonephritis is obviously associated with the phytocomponents of the drug. The effect on the size of the stones is largely due to the presence of sodium and potassium citrates in the complex. Citrate is one of the main inhibitors of crystallization. This effect is realized in both calcium oxalate and urate nephrolithiasis, although the mechanisms differ. Stabilization of the colloidal state of urine, normalization of the acidity index prevents the crystallization of salts and the growth of calculi.

Conclusion. Chronic calculous pyelonephritis, which occurs against the background of small calyx calculi of the kidney, is a variant of a combined pathology that is widely encountered in urological practice. The dominant concept of management of this group of patients is to conduct conservative treatment.

A pronounced acid reaction of urine in combination with crystalluria of one kind or another is a significant factor in the progression or recurrence of stone formation and the severe course of the inflammatory process. The present study shows that the correction of these disorders has a positive effect on the course of both diseases.