If Fildena Double 200 mg contains sildenafil, its use should be monitored by a doctor or qualified healthcare professional, particularly because 200 mg is above the usual maximum recommended sildenafil dose of 100 mg once daily. D DailyMed +1 A clinician should review: Blood pressure and cardiovascular health, especially if there is heart disease or low blood pressure. Other medicines, particularly nitrates, Fildena Double 200 mg  -blockers, and certain CYP3A4 inhibitors. Nitrates must not be combined with sildenafil because of the risk of a dangerous blood-pressure drop. D DailyMed Kidney or liver problems, which can increase sildenafil levels and side effects. D DailyMed Side effects such as severe dizziness, vision changes, chest pain, or an erection lasting more than 4 hours. D DailyMed Because 200 mg exceeds the standard recommended maximum, I would not recommend taking Fildena Double 200 mg without medical supervision.