Brief Answer:
It is prescription only.
Detailed Answer:
Hello!
Thank you for the query.
It is important to use it regularly. It changes the urine composition what prevents stones formation. And such formation is a very slow process. That is why regularity is the key in stones prevention.
Potassium citrate under brand name Urocit-K is prescription only medicine.
Hope this will help. Feel free to ask further questions.
Regards.