- Current treatment or treatment within 30 days prior to the first dose of Study Drug (active or placebo; Day 4) with magnesium-containing antacids or laxatives, dietary supplement(s) where the total daily dose of magnesium is greater than 150 mg, central nervous system depressants, neuromuscular blocking agents, or cardiac glycosides, lithium-containing drugs, bisphosphonates, sodium polystyrene sulfonate, or tetracycline/quinolone antibiotics, anti-tumor necrosis factor-alpha drugs, or phytotherapeutic/herbal/ plant derived preparations