Fildena CT 100 can cause dizziness if it contains sildenafil 100 mg, as the Fildena product is marketed as. Dizziness is a recognized side effect of sildenafil; in clinical trials, it occurred in about 3–4% of people taking sildenafil at studied doses. F FDA Access Data +1 The dizziness can be related to lowered blood pressure, and the risk can be greater with blood-pressure medicines, alpha-blockers, Fildena CT 100 , or certain heart medicines. F FDA Access Data Because you've mentioned heart problems earlier, don't ignore significant dizziness—especially if it occurs with chest pain, fainting, severe weakness, shortness of breath, or an unusually fast/irregular heartbeat. Stop sexual activity and seek urgent medical care if these occur. F FDA Access Data If you tell me which heart medicines you take, I can check specifically whether they could be contributing to the dizziness or interact with Fildena 100.