Malegra is available in different strengths and formulations, so the amount of sildenafil can vary. Common side effects may include headache, facial flushing, indigestion, nasal congestion, dizziness, and temporary visual changes. Taking more than the recommended dose can increase the risk of adverse effects. An important safety consideration is the interaction between sildenafil and nitrate medicines, including certain medicines used for angina or chest pain. Combining them can cause a potentially dangerous drop in blood pressure.