Before taking bismuth subsalicylate, tell your doctor or pharmacist if you are allergic to it; or if you are allergic to aspirin, to salicylates (such as salsalate), or to NSAIDs (such as ibuprofen, naproxen, celecoxib); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. This medication may react with other medications (such as tetracycline antibiotics, chloroquine), preventing them from being fully absorbed by your body. Talk with your doctor or pharmacist about how to schedule your medications to prevent this problem. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: bleeding problems (such as hemophilia), bloody/black/tarry stools. It is unknown if this medication passes into breast milk. However, similar drugs pass into breastmilk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: valproic acid, carbonic anhydrase inhibitors (such as acetazolamide), corticosteroids (such as prednisone), methotrexate.