Before taking ranitidine, tell your doctor or pharmacist if you are allergic to it; or to other H2 blockers (e.g., cimetidine, famotidine); 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.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: a certain blood disorder (porphyria), immune system problems, kidney problems, liver problems, lung diseases (e.g., asthma, chronic obstructive pulmonary disease-COPD), other stomach problems (e.g., tumors).
Some symptoms may actually be signs of a more serious condition. Get medical help right away if you have: heartburn with lightheadedness/sweating/dizziness, chest/jaw/arm/shoulder pain (especially with shortness of breath, unusual sweating), unexplained weight loss.
Older adults may be more sensitive to the side effects of this drug, especially confusion.
Ranitidine should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.
Ranitidine passes into breast milk. Consult your doctor before breast-feeding.
Some products need stomach acid so that the body can absorb them properly. Ranitidine decreases stomach acid, so it may change how well these products work. Some affected products include atazanavir, dasatinib, delavirdine, certain azole antifungals (such as itraconazole, ketoconazole), pazopanib, among others.
Do not use this medication with other products that contain ranitidine or other H2 blockers (cimetidine, famotidine, nizatidine).
This medication may interfere with certain laboratory tests (including certain urine protein tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.