Fildena 150Viagra contains the potent ingredient Sildenafil Citrate which is first industrialized as an angina drug. However, the drug sildenafil citrate was not as effective for angina. Viagra contains the potent ingredient Sildenafil Citrate which was first industrialized as a drug against angina pectoris. However, the drug sildenafil citrate was not too effective for angina and instead gave a strange side effect of improving the patient's erectile response. since marketed the product and marketed the product as a real treatment for erectile dysfunction.