Therapeutic target
To avoid stone recurrence (recurrence of urinary stones).
Therapy recommendations
Reduction of risk factors
- Behavioral risk factors
- Dehydration (dehydration of the body due to fluid loss or lack of fluid intake).
- High protein (protein-rich) diet
- Diet rich in table salt
- Disease-related risk factors
- Cystinuria (cystinuria), autosomal recessive inheritance.
Nutritional therapy
- Fluid intake of at least 3.5 l / day for urine dilution (urine dilution); drinking amount thereby evenly distribute over 24 h
- Limit protein intake (intake: 0.8-1.0 g/kg bw/day).
- Limit table salt intake (circa 3 g table salt per day, equivalent to 1.2 g sodium)
- Alkaline-rich, alkalizing diet with potatoes, vegetables, salads, legumes and fruit; dietary supplements with alkalizing (basic) mineral compounds potassium citrate, magnesium citrate and calcium citrate, as well as vitamin D and zinc (zinc contributes to the normal acid-base balance).
Active substances of metaphylaxis
- Potassium citrate, magnesium citrate and calcium citrate for urinary alkalinization (measure urine pH before each intake; see also under daily profile of urine pH, measurement protocol), sodium carbonate if necessary.
- Ascorbic acid (improves the ratio of non-soluble cystine to soluble cysteine, thus reducing the rate of recurrent stones).
- Alpha-mercaptopropionylglycine (to normalize cystine excretion; starting at a cystine excretion of > 3 mmol/day).
- Tiopronin (chelating agent); indication: when alkalinization therapy is insufficient or when cystine excretion is extremely high, > 3 mmol/day.
- In case of tiopronin intolerance, the administration of captopril (ACE inhibitor) at a dosage of 75-150 mg (in children: 2-5 mg/kg bw/d) daily as second-line treatment.
