Viagra Online UK

Viagra contains sildenafil, the first phosphodiesterase type 5 (PDE5) inhibitor to be developed for the treatment of erectile dysfunction.

Since its introduction in 1998, sildenafil has become one of the most recognised and widely prescribed medications for erectile difficulties, helping millions of men worldwide to achieve and maintain erections sufficient for satisfactory sexual intercourse.

Sildenafil works by inhibiting PDE5, the enzyme responsible for the breakdown of cyclic guanosine monophosphate (cGMP) in the corpus cavernosum.

During sexual stimulation, nitric oxide is released in the erectile tissue, activating guanylate cyclase and increasing cGMP levels.

cGMP relaxes smooth muscle, allowing increased blood flow into the penis. By preventing cGMP degradation, sildenafil sustains and enhances this natural erectile process.

Viagra has a well-established efficacy and safety profile across diverse patient populations, including men with diabetes, those who have undergone radical prostatectomy, and those with spinal cord injuries.

Its effects are typically felt within 30 to 60 minutes and last for approximately four to six hours.

Take one Viagra tablet approximately one hour before anticipated sexual activity. Swallow the tablet whole with a glass of water.

Viagra may be taken with or without food, but a high-fat meal may delay the onset of action by up to one hour. Do not take more than one dose in 24 hours.

Sexual stimulation is required for the medication to be effective; it does not produce an automatic erection.

Avoid excessive alcohol consumption, as it can impair erectile function and intensify side effects.

The recommended starting dose is 50 mg, taken approximately one hour before sexual activity. Based on efficacy and tolerability, the dose may be increased to a maximum of 100 mg or reduced to 25 mg.

Maximum one dose per day. In patients aged 65 and over, those with hepatic or renal impairment, or those taking CYP3A4 inhibitors, a starting dose of 25 mg is recommended.

Sildenafil is not recommended in patients with severe hepatic impairment.

Very common (more than 1 in 10): headache, flushing.

Common (1 in 10 to 1 in 100): nasal congestion, dizziness, visual disturbances (including blue-tinged vision and increased light sensitivity), dyspepsia, nausea.

Uncommon (1 in 100 to 1 in 1,000): somnolence, palpitations, tachycardia, vomiting, rash, epistaxis, myalgia, haematuria, chest pain.

Rare (1 in 1,000 to 1 in 10,000): priapism, non-arteritic anterior ischaemic optic neuropathy (NAION), sudden sensorineural hearing loss.

Seek urgent medical attention for an erection lasting more than four hours or sudden visual or hearing loss.

Viagra must not be taken with nitrates or nitric oxide donors in any form, as this combination can cause a severe and potentially fatal hypotensive episode.

Allow at least 24 hours between Viagra and any nitrate administration. Use with caution in patients on alpha-blockers and ensure stable alpha-blocker dosing before initiating sildenafil.

Patients with significant cardiovascular disease should be assessed for fitness for sexual activity before starting PDE5 inhibitor therapy.

Report any sudden visual disturbance or hearing loss immediately.

Viagra is contraindicated in patients taking nitrates or nitric oxide donors, those with severe cardiovascular disease (recent myocardial infarction or stroke within 6 months, unstable angina, severe heart failure), patients with hypotension (blood pressure below 90/50 mmHg), those who have lost vision in one eye due to NAION, those with hereditary retinal disorders such as retinitis pigmentosa, severe hepatic impairment, and hypersensitivity to sildenafil or any excipient.