Pseudomembranous colitis, ventricular arrhythmias. Patients w/ CNS disorders, myasthenia gravis, G6PD deficiency, galactose intolerance, Lapp-lactase deficiency or glucose-galactose malabsorption, visual impairment or any effect on the eyes, psychosis or history of psychiatric disease. Concomitant use w/ medication that reduce K & Mg. Discontinue treatment at 1st sign of pain or inflammation, cardiac arrhythmia, symptoms related to liver failure, neuropathy, skin &/or mucosal reactions. Avoid exposure to UV irradiation & extensive sunlight. Maintain adequate fluid intake. Perform LFTs. May cause false -ve Mycobacterium culture test result, dysglycemia. Not recommended for MRSA infections. Patients for whom Na intake is of medical concern (eg, CHF, renal failure, nephrotic syndrome). Not recommended in patients w/ complicated pelvic disease for whom an IV treatment is necessary. May impair ability to drive or operate machinery due to CNS reactions & vision disorders. Women. Elderly.