Sildenafil
Indications for use
- OTC sildenafil is indicated for use in adult men with erectile dysfunction (the inability to achieve or maintain a penile erection sufficient for satisfactory sexual performance)
- Supply of the product will depend on pharmacists’ assessment of its suitability
- There are currently several OTC products listed on the electronic medicines compendium (including Viagra Connect, Viagra Connect Melts, Aronix and Liberize)
Age
- Men aged 18 years +
Dose/directions
- One 50 mg tablet taken with water approximately one hour before sexual activity (NB: in order for it to be effective, sexual stimulation is required)
- the amount of time required for the medicine to work varies from person to person, but it normally takes between 30 to 60 minutes to work and patients may take it up to 4 hours before sexual activity
- The maximum recommended dosing frequency is once per day
- If taken with food, the onset of activity may be delayed compared to the fasted state. It should not be taken with grapefruit or grapefruit juice. It also warns that drinking excessive alcohol can temporarily reduce the ability to get an erection (therefore advises patients not to drink large amounts of alcohol before sexual activity)
- Viagra Connect Melts (50 mg orodispersible film, available in UK pharmacies from 27 April 2026) is bioequivalent to the 50 mg film-coated tablet. The SmPC specifies that the film should be placed on the tongue on an empty stomach approximately one hour before sexual activity, since concomitant food intake (particularly a high-fat meal) delays absorption and onset of effect. The maximum dosing frequency remains one 50 mg film per day
- For the orodispersible film, the SmPC instructs that the aluminium pouch should be carefully peeled open (not cut), the film removed with a dry finger and placed on the tongue, and allowed to disintegrate with or without water. Saliva may be swallowed during disintegration, but the film itself should not be swallowed. The film should be placed on the tongue immediately upon removal from the pouch
Duration
- Patients may need to take it a number of times on different occasions (a maximum of one 50 mg tablet per day), before they can achieve a penile erection satisfactory for sexual activity. If after several attempts on different dosing occasions patients are still not able to achieve this, they should be advised to consult a doctor
- All men with erectile dysfunction should be advised to consult their doctor within 6 months for a clinical review of potential underlying conditions
- If symptoms have not improved after taking it on several consecutive occasions, or if symptoms of erectile dysfunction worsen, the patient should be advised to consult their doctor
Contra-indications/referral criteria
- Hypersensitivity
- Co-administration with the following is contra-indicated: nitric oxide donors (such as amyl nitrite) or nitrates, ritonavir, guanylate cyclase stimulators (such as riociguat)
- Patients taking alpha blockers should be advised to consult their doctor before taking as a 25 mg tablet may be more suitable for them
- Sildenafil should not be used by men for whom sexual activity may be inadvisable, and these patients should be referred to their doctor. This includes patients with severe cardiovascular disorders such as a recent (6 months) acute myocardial infarction or stroke, unstable angina or severe cardiac failure. Furthermore, patients previously diagnosed with the following must be advised to consult with their doctor before resuming sexual activity: uncontrolled hypertension, moderate to severe valvular disease, left ventricular dysfunction, hypertrophic obstructive and other cardiomyopathies, or significant arrhythmias
- Patients with increased susceptibility to vasodilators include those with left ventricular outflow obstruction or those with the rare syndrome of multiple system atrophy manifesting as severely impaired autonomic control of blood pressure. Men with these conditions must not use the product without first consulting a doctor
- Sildenafil should not be used in patients with severe hepatic impairment, hypotension and known hereditary degenerative retinal disorders. Patients with severe renal impairment must be advised to consult their doctor before taking since a 25 mg tablet may be more suitable for them
- Sildenafil is also contra-indicated in patients who have loss of vision in one eye because of non-arteritic anterior ischaemic optic neuropathy
- The use of sildenafil is not recommended in patients with history of bleeding disorders or active peptic ulceration, and should only be administered after consultation with a doctor
- It should not be administered to men with rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption
- The above galactose-intolerance / lactase-deficiency / glucose-galactose malabsorption advice applies to the 50 mg film-coated tablet, whose film coat contains lactose. Viagra Connect Melts (50 mg orodispersible film) does not contain lactose and the SmPC carries no equivalent warning, so it may be a suitable alternative for men with these rare hereditary problems
- Patients with anatomical deformation of the penis (moreover, patients who have any condition which can cause priapism or those who have previously experienced priapism should consult their doctor prior to OTC use)
- It is not indicated for use by women
- It is not intended for men without erectile dysfunction or for males under 18 years of age
Examples of drug interactions
- Sildenafil metabolism is principally mediated by the cytochrome P450 (CYP) isoforms 3A4 and 2C9;inhibitors of these isoenzymes may reduce sildenafil clearance and inducers of these isoenzymes may increase sildenafil clearance. Grapefruit juice may give rise to modest increases in plasma levels of sildenafil
- Nitrates or nitric acid donors (including nicorandil)
- Alpha blockers
- The safety and efficacy of sildenafil used concomitantly with other treatments for erectile dysfunction have not been studied and therefore this combination is not recommended
Side-effects
- The most commonly reported adverse reactions were: headache, flushing, dyspepsia, nasal congestion, dizziness, nausea, hot flush, visual disturbance, cyanopsia and blurred vision
- Patients should be advised that in the event of any sudden visual defect, they should stop taking and seek medical attention immediately
- As dizziness and altered vision have been reported, patients should be aware of how they react to the medicine before driving or performing skilled tasks
- Prolonged erections and priapism have been occasionally reported with sildenafil in post-marketing experience. The patient should seek immediate medical assistance if an erection persists for longer than 4 hours
- Patients should be advised to stop taking and seek medical attention if they experience: chest pains (and NOT to use nitrates to treat this), a seizure, a serious skin reaction or clinical features suggesting hypersensitivity
Other pertinent information
- Since there is a degree of cardiac risk associated with sexual activity, the cardiovascular status of men should be considered prior to initiation of therapy (see the SmPC for further guidance and referral to a medical practitioner for further CV risk assessment may be required). Furthermore, serious cardiovascular events have been reported withuse and most, but not all, of these patients had pre-existing cardiovascular risk factors
- The orodispersible-film formulation (Viagra Connect Melts) shares the same indications, age limit (men 18+), contraindications, drug interactions and side-effect profile as the 50 mg film-coated tablet
- Reclassified POM→P: 2017