A solid oral pharmaceutical composition in the form of at least one tablet, the tablet consisting of a core including at least one bicarbonate salt as active ingredient and at least one prolonged-release matrix, and of a coating including at least one coating agent, the composition allowing continuous release in vivo over a period from after a quarter of an hour and up to twelve hours after taking a single dose, for use thereof as a medicament, in particular in the treatment and/or prevention of urinary lithiasis and related diseases, occurring at a physiological pH and/or during urinary acidosis and/or during hypobicarbonataemia and/or during hypocitraturia and/or during hypercalciuria and/or during hyperoxaluria.
