A few of the conditions you should let your healthcare provider know about before you take sildenafil citrate include sickle cell anemia, multiple myeloma, leukemia, and high blood pressure. Among the people who should not take sildenafil citrate at all are those who are taking a nitrate for angina and those who are allergic to any component of sildenafil citrate. Some other precautions and warnings for sildenafil citrate include potential drug interactions and the risk of serious side effects such as a heart attack, stroke, or sudden death in some people taking this medicine.
Also, tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, antacids, vitamins, and herbal supplements.