Sildenafil

Sildenafil is a prescription-only PDE5 inhibitor taken as needed to help achieve and maintain an erection sufficient for sexual activity. Sildenafil is used for Erectile dysfunction.

Also called: Vybrique (United States) · Sildatio Pht (Australia) · Andros (Philippines)

Pronunciation: sil-DEN-a-fil.

Generic name: sildenafil
Drug class: Phosphodiesterase type 5 (PDE5) inhibitor
Form: Film-coated tablets, 25 mg/50 mg/100 mg
Route: Oral
Legal status: Prescription-only (some countries also permit pharmacist-supplied over-the-counter versions for erectile dysfunction)

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · India · Nepal · New Zealand

Australia: Sildenafil Sandoz PHT, SILDATIO PHT, Sildenafil PHT APOTEX, SILDENAFIL PHT ARX, Vasafil, Vedafil, Sildenafil APOTEX, Sildenafil Sandoz · Full directory

What sildenafil is and how it works

Sildenafil is a prescription-only PDE5 inhibitor taken as needed to help achieve and maintain an erection sufficient for sexual activity. Sexual stimulation is still required for it to work. (1)

Take sildenafil only as your prescriber directs. The single most important safety rule is this: never take sildenafil if you use any nitrate medicine, in any form, even occasionally -- the combination can cause a severe, potentially life-threatening drop in blood pressure.

Mechanism of action: how sildenafil works

Sildenafil selectively inhibits phosphodiesterase type 5 (PDE5), the enzyme responsible for degradation of cyclic GMP in the corpus cavernosum, enhancing the nitric-oxide-mediated increase in blood flow that produces an erection in response to sexual stimulation. (1)

What is Sildenafil used for?

Erectile dysfunction

Used to treat erectile dysfunction (difficulty achieving or maintaining an erection) in adult men. (1)

Before taking sildenafil

Do not take / not appropriate for

Do not take sildenafil if you use any nitrate medicine in any form -- regularly or only occasionally -- including nitroglycerin, isosorbide dinitrate, or isosorbide mononitrate (often used for chest pain/angina). Combining the two can cause a severe, potentially fatal drop in blood pressure. (all countries) (1)
Do not take sildenafil if you take a guanylate cyclase stimulator such as riociguat, for the same severe blood-pressure risk. (all countries) (1)
Do not take sildenafil if you have had a serious allergic reaction to it or any of its ingredients. (all countries) (1)

Tell your clinician about

Any heart condition, including whether sexual activity is safe for you -- your prescriber needs to confirm your heart can handle the physical exertion of sex.
Whether you take an alpha-blocker medicine (often used for blood pressure or an enlarged prostate).
Any history of an erection lasting longer than 4 hours, sickle cell disease, multiple myeloma, leukaemia, or a physical deformity of the penis (such as Peyronie's disease).
Any history of sudden vision or hearing loss.
Kidney or liver problems.
All other medicines you take, including any nitrates you use only occasionally.

(1)

Sildenafil dosage and how to take it

Take sildenafil as needed, roughly 1 hour before sexual activity -- it can work anywhere from about 30 minutes to 4 hours after taking it.
Take no more than one dose in a 24-hour period.
Sexual stimulation is still needed for sildenafil to work -- it does not cause an erection on its own.

(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (3) (2) (4) (5) (6)

Missed dose

Sildenafil is taken as needed rather than on a fixed daily schedule, so a 'missed dose' does not apply in the usual sense -- take it only when needed, up to once per day, following your prescriber's instructions.

Overdose

Seek emergency medical help immediately if too much sildenafil has been taken, or if severe dizziness, fainting, or a prolonged erection occurs. (1)