While taking Cenforce 150mg (which contains sildenafil citrate), you should seek immediate medical attention if you experience any severe or unusual symptoms. These include chest pain, irregular heartbeat, shortness of breath, or fainting—signs that could indicate a serious cardiovascular issue. Vision changes, such as sudden loss of vision in one or both eyes, or hearing loss, may also signal a rare but serious reaction requiring urgent care. If you experience a painful or prolonged erection lasting more than 4 hours (priapism), it is a medical emergency. Allergic reactions such as swelling of the face, lips, or throat, and difficulty breathing also warrant immediate medical help. Always consult a doctor if unsure. Have you noticed any side effects already?