Sildenafil Citrate is a phosphodiesterase type 5 (PDE5) inhibitor. It works by blocking the enzyme PDE5, which leads to increased levels of cyclic GMP in the smooth muscle of the penis. This results in enhanced blood flow and helps achieve and maintain an erection when sexually stimulated.The dosage generally starts at 50 mg. It can be adjusted based on individual needs and tolerability, up to a maximum of 100 mg.