Heavy use of some cough medicines may be associated with nephrolithiasis. The implicated cough medicine contain guaifenesin with or without ephedrine.
Guaifenesin is an expectorant and cough suppressant present in products such as Mucinex
The stones are:
(1) radiolucent (not seen on regular X-rays)
(2) contain metabolites of guaifenesin and ephedrine (if present)
The risk is reduced if the urine in alkalinized.
Some of the patients affected were abusing the medicine and have substance abuse problems.
