Why would magnesium and potassium be low?
Other causes include diarrhea; alcoholism; intrinsic renal tubular transport disorders such as Bartter and Gitelman syndromes; and tubular injuries from nephrotoxic drugs, including aminoglycosides, amphotericin B, cisplatin, etc. Concomitant magnesium deficiency has long been appreciated to aggravate hypokalemia.