![]() | |
![]() | |
Clinical data | |
---|---|
Pronunciation | /sɪlˈdɛnəfɪl/ sil-DEN-ə-fil |
Trade names | Viagra, others |
AHFS/Drugs.com | Monograph |
MedlinePlus | a699015 |
License data |
|
Pregnancy category |
|
Routes of administration | Oral, intravenous, sublingual |
ATC code | |
Legal status | |
Legal status | |
Pharmacokinetic data | |
Bioavailability | 41% (mean)[7] |
Protein binding | ~96% |
Metabolism | Liver: CYP3A4 (major route), CYP2C9 (minor route) |
Metabolites | N-desmethylsildenafil (~50% potency for PDE5) |
Onset of action | 20 minutes |
Elimination half-life | 3–4 hours |
Excretion | Feces (~80%), urine (~13%)[4] |
Identifiers | |
| |
CAS Number |
|
PubChem CID | |
DrugBank |
|
ChemSpider | |
UNII |
|
KEGG | |
ChEBI |
|
ChEMBL |
|
PDB ligand | |
CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.122.676 |
Chemical and physical data | |
Formula | C22H30N6O4S |
Molar mass | 474.58 g·mol−1 |
3D model (JSmol) | |
| |
| |
![]() ![]() |
Sildenafil, sold under the brand name Viagra, among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension.[4][8] It is also sometimes used off-label for the treatment of certain symptoms in secondary Raynaud's phenomenon.[9] It is unclear if it is effective for treating sexual dysfunction in females.[8] It can be taken orally (swallowed by mouth), intravenously (injection into a vein), or through the sublingual route (dissolved under the tongue).[8][10] Onset when taken orally is typically within twenty minutes and lasts for about two hours.[8]
Common side effects include headaches, heartburn, and flushed skin.[8] Caution is advised in those with cardiovascular disease.[8] Rare but serious side effects include vision problems, hearing loss, and prolonged erection (priapism) that can lead to damage to the penis.[8] Sildenafil should not be taken by people on nitric oxide donors such as nitroglycerin (glycerin trinitrate), as this may result in a serious drop in blood pressure.[8]
Sildenafil acts by blocking phosphodiesterase 5 (PDE5), an enzyme that promotes breakdown of cGMP, which regulates blood flow in the penis.[8] It requires sexual arousal to work, and does not by itself cause or increase sexual arousal.[8] It also results in dilation of the blood vessels in the lungs.[8]
Pfizer originally discovered the medication in 1989 while looking for a treatment for angina.[11] It was approved for medical use in the United States and in the European Union in 1998.[5][8][11][12] In 2021, it was the 157th most commonly prescribed medication in the United States, with more than 3 million prescriptions.[13][14] It is available as a generic medication.[15][16] In the United Kingdom, it is available over the counter.[17]
Viagra FDA label
was invoked but never defined (see the help page).Raynaud's treatment - sildenafil + other PDE5 inhibitors
was invoked but never defined (see the help page).sublingual
was invoked but never defined (see the help page).