Alkalinization of urine helps in dissolution of which types of renal stones?

Many uric acid stones can be dissolved by raising urinary pH levels to 6.5 with use of alkalinizing agents. (sodium bicarbonate or potassium citrate) . The point to be kept in mind is uric acid remains undissolved in ph < 5.5 and dissolves in ph above that . Although alkali therapy may help in cystine stones, it is impoant to remember that the pKa of cystine is 8.3, it is quite difficult to achieve a urine pH this high, making excessive alkalinization an unrealistic target. Secondly, raising the urine pH to these levels will put the patient at risk for the formation of calcium phosphate calculi Thus Uric acid stones is best option Source : Bailey 27th ed , chapter 76 , pg no : 1408 Campbell and Walsh Urology 11th edition