Editing Stones: Diet and Pharmacologic Management (section)

===Cystine stones===
*'''<span style="color:#ff0000">First-line therapy for patients with cystine stones:</span>'''
*#'''<span style="color:#ff0000">Increased fluid intake</span>'''
*#'''<span style="color:#ff0000">Urinary alkalinization</span>'''
*#'''<span style="color:#ff0000">Restriction of sodium and protein intake</span>'''
*##Excess dietary sodium can lead to increases in cystine excretion
*'''<span style="color:#ff0000">Potassium citrate should be offered to patients with cystine stones to raise urinary pH to an optimal level</span>'''
**'''AUA: Urine pH of 7.0 (CUA targets >7.0) should be achieved'''
*'''<span style="color:#ff0000">Cystine-binding thiol drugs, such as alpha-mercaptopropionylglycine (tiopronin), should be offered to patients with cystine stones who are unresponsive to dietary modifications and urinary alkalinization, or have large recurrent stone burdens.</span>'''
**'''MOA: increase cystine solubility in urine by formation of a more soluble mixed-disulfide bond (i.e., cystine to drug, rather than cystine to cystine).'''
**'''Options include α-mercaptopropionylglycine (tiopronin [Thiola]),''' D-penicillamine (Cuprimine), and captopril
***'''Tiopronin is possibly more effective and associated with fewer adverse events than d-penicillamine and should be considered first.'''
***'''Captopril, another thiol agent, has not been shown to be effective for the prevention of recurrent cystine stones'''
***d-Penicillamine and α-MPG are equally effective in their ability to decrease urinary cystine levels. However, α-mercaptopropionylglycine is significantly less toxic than d-penicillamine.
***Side effects of '''D-penicillamine''' include gastrointestinal disturbances, fever and rash, arthralgia, leukopenia, thrombocytopenia, proteinuria with nephrotic syndrome, polymyositis, and '''pyridoxine (Vitamin B6) deficiency'''
****'''Pyridoxine (vitamin B6) deficiency supplementation is recommended'''