Why crystalluria is the side effect of sulphonamides?

Beause they have strong intermolecular bonding which decreases their water solubility as water can not get in between the molecules to solvate them. They are also used at a relativley high dose meaning there is a increased chance for these bonds to occur. The bonds cause complexation and precipitation. Sulfonamides can also be precipitated due to the fact that urine is acidic and the pka of some sulfonamides is greater than the pH of urine.