Malegra 100 is not automatically safe for all heart patients. It depends on the type and severity of heart disease and the medications the person is already taking. The biggest safety concern is its interaction with nitrates (such as nitroglycerin or isosorbide drugs used for chest pain). Combining sildenafil with nitrates can cause a dangerous and sudden drop in blood pressure, which may lead to fainting, heart attack, or stroke. Because of this, Malegra 100 is strictly contraindicated in patients using any nitrate medication. Caution is also required in people with recent heart attack, recent stroke, unstable angina, severe heart failure, or uncontrolled blood pressure. In these cases, ***** activity itself may already be risky for the heart, so the medication is usually avoided until a cardiologist confirms it is safe. Some heart patients who are stable and not using nitrates may be able to use sildenafil, but typically at lower doses (25–50 mg rather than 100 mg) under medical supervision. Doctors assess cardiovascular fitness before prescribing it.