- Anyone taking the following medications: diuretics, nonsteroidal anti-inflammatory agents, methyldopa, tetracycline, antipsychotic, neuromuscular blocking agents, digoxin, phenytoin, acetazolamide, calcium iodide, iodinated glycerol, potassium iodide, calcium channel blockers and/or metronidazole. Patients on these medications may be enrolled and their lithium levels will be followed very closely. If levels are consistently maintained, the subject may remain in the study.