Viagra is the trade name and generic name of Sildenafil Citrate Tablets, Sildenafil Citrate Tablets 100mg works to treat erectile dysfunction. Sildenafil citrate tablets enhance the nitric oxide (NO)-cGMP pathway through selective inhibition of PDE5, elevating cGMP levels and leading to relaxation of penile cavernous smooth muscle, so that patients with erectile dysfunction produce a natural erectile response to sexual stimulation. It is commonly used clinically for erectile dysfunction. Adverse reactions such as nausea and vomiting, rash, and headache may occur with the use of this medication, which are generally transient, mostly mild to moderate in nature, and resolve on their own after discontinuation of the drug. Patients taking any dosage form of nitrate, either regularly or intermittently, need to be disabled. It is also contraindicated in patients who are allergic to the drug. Sildenafil is not suitable for women, as well as children. Patients are advised to use Sildenafil Citrate tablets under medical supervision.