nephrology

Question 1

Management of cystinuria and accompanying cystine stones .

Answer 1

recurrent stone in the first 2 decades of life should call attention to the possibility of cystinuria .
Confirmed by the elevated cystine levels in 24 hr urine
ground glass semi-opaque stones on xray
Hydration and alkalinazation with potassium citrate are first line
sodium bicarbonate because of increased blood pressure
2nd line is chelation with D-penicillamine -renders cysteine 50 times more soluble than cystine
Adverse reactions are common, and the newer agent alpha-mercaptopropionylglycine is better
Captopril is used in patients with concomitant hypertension.