Raloxifene Calcium carbonate

The absorption of raloxifene is reduced by colestyramine, and their concurrent use is not recommended. No clinically relevant changes in raloxifene pharmacokinetics occur with alumini-um/magnesium hydroxide, amoxicillin, ampicillin or calcium carbonate. Raloxifene does not alter digoxin or methylprednisolone levels. Oral antibacterials, antihistamines, aspirin, benzodiazepines, H2-receptor antagonists, ibuprofen or paracetamol (acetaminophen) were used in clinical studies without any obvious effect on raloxifene levels. Smoking does not appear to alter the efficacy of raloxifene. 

Interference with T4 absorption Cholestyramine, chromium picolinate, colestipol, ciprofloxacin, proton pump inhibitors, sucralfate, sodium polystyrene sulfonate, raloxifene, sevelamer hydrochloride, aluminum hydroxide, ferrous sulfate, calcium carbonate, bran, soy, coffee. 

Patients with hypothyroidism who are taking levothyroxine may become hypothyroid if given drugs that decrease T4 absorption (cholestyramine, iron salts, calcium carbonate, aluminum hydroxide, sucralfate, raloxifene, omeprazole, dietary soy and fiber), increase its clearance (phenytoin, car-bamazepine, phenobarbital, rifampin), or decrease T4 to T3 conversion (amiodarone, glucocorticoids, propranolol). 

The manufacturers of raloxifene report that in studies, an antacid containing aluminium/magnesium hydroxide given 1 hour before and 2 hours after raloxifene had no effect on its absorption. Also, no interaction was seen with calcium carbonate. There would therefore appear to be no reason for avoiding concurrent use. 

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