Tadasoft 40 mg is unsafe if you take it with nitrate medicines or if you have certain serious heart problems, because it can cause a dangerous drop in blood pressure. It should also be avoided in people with severe liver disease, recent heart attack, severe heart failure, unstable angina, allergy to tadalafil, or in children and women. Situations to avoid Nitrate medicines for chest pain or heart disease. Recent heart attack or unstable heart disease. Severe liver disease. Severe kidney disease without medical advice. Allergy to tadalafil or similar ED medicines. Use with other ED medicines unless a doctor specifically approves it. Use with caution Mild to moderate liver problems. Moderate to severe kidney impairment. Alcohol use, because it can worsen dizziness and low blood pressure. Grapefruit juice, because it may raise drug levels. Conditions like stomach ulcers, retinitis pigmentosa, or blood disorders such as sickle cell anemia. Get urgent help Seek immediate medical care if you get chest pain, fainting, sudden vision or hearing loss, or an erection lasting more than 4 hours. Important note Tadasoft 40 mg is a high-dose tadalafil product, so it is especially important to use it only if a clinician has prescribed it for you.