Caverta (Generic Sildenafil Citrate Tablets) is used to treat erectile dysfunction also known as impotence. Sildenafil tablets helps a man with erectile dysfunction get and keep an erection only when he is sexually excited (stimulated). Sildenafil works by increasing blood flow to the penis to help a man get and keep an erection. Caverta tablets are available in strengths of 25 mg, 50 mg and 100 mg.