On the other hand, spironolactone was developed as a diuretic. It is potassium-sparing, that is to say, it does not remove potassium from the system in the manner of other diuretics.
Low potassium, and other low levels of electrolytes, have been associated with muscle cramping. As has dehydration.
With that said, the symptoms noticed by the original poster could have other causes, not associated with spironolactone.