Male erectile dysfunction is treated with the drug silagra. The active component of it is sildenafil citrate, a phosphodiesterase type 5 inhibitor. By boosting blood flow to the penis during sexual stimulation, sildenafil citrate helps men get and keep an erection. One pill taken orally with a full glass of water, half an hour to an hour before sexual activity, is the normal suggested dosage. Only when there is sexual stimulation present does sildenafil citrate work. Only in the context of sexual excitement does silagra work.