Over the years sildenafil has proved to be very effective and very safe for most men. The main concerns about safety relate to use in those with recent cardiovascular disease events, such as myocardial infarction or stroke, and the use at the same time as nitrate drugs for angina. The following restrictions apply to the sale of Viagra Connect:

• Age – men must be over 18 years

• Medical contraindications:

• Heart attack or stroke within the last six months
• Low blood pressure (hypotension <90/50mmHg)
• Poorly or uncontrolled high blood pressure
• Unstable angina (chest pain)
• Irregular heart beat or palpitations (arrhythmia)
• Heart problems: valve disorders; left outflow obstruction; aortic narrowing; cardiomyopathy
• Severe heart failure
• Previously diagnosed hepatic disease (including cirrhosis of the liver)
• Severe renal impairment (e.g. eGFR or creatinine clearance <30)
• Blood disorders: sickle cell anaemia; multiple myeloma or leukaemia; haemophilia
• Active stomach or duodenal ulcers
• Pulmonary arterial hypertension (rare)
• Peyronie’s disease or any other conditions causing deformation of the penis (rare)
• Loss of vision because of damage to the optic nerve or an inherited eye disease such as retinitis pigmentosa (rare).

• Contraindicated medicines:

• Nitrates (nicorandil or other nitric oxide donors e.g. glyceryl trinitrate, isosorbide mononitrate or isosorbide dinitrate), as sildenafil increases the hypotensive effects of nitrates
• ‘Poppers’ for recreational purposes (e.g. amyl nitrite)
• Riociguat or other guanylate cyclase stimulators for pulmonary hypertension
• CYP3A4 inhibitors: e.g. saquinavir (to treat HIV), cimetidine (a heartburn treatment), itraconazole or ketoconazole (to treat fungal infections), erythromycin or rifampicin (antibiotics) or diltiazem (for high blood pressure). In patients taking ritonavir (to treat HIV/AIDs), sildenafil is contraindicated because of a four-fold increase in sildenafil concentration results
• Alpha-blockers, such as alfuzosin, doxazosin or tamsulosin.