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Sildenafil oral 25mg, 50mg, 100mg


Oral formulations of sildenafil for treatment of erectile dysfunction.

Drugs List

  • ARONIX 50mg tablets
  • LIBERIZE 50mg tablets
  • sildenafil 100mg tablets
  • sildenafil 25mg tablets
  • sildenafil 50mg tablets
  • VIAGRA 100mg tablets
  • VIAGRA 25mg tablets
  • VIAGRA 50mg tablets
  • VIAGRA CONNECT 50mg tablets
  • VIZARSIN 100mg film coated tablets
  • VIZARSIN 25mg film coated tablets
  • VIZARSIN 50mg film coated tablets
  • ZAMANTOS 50mg tablets
  • Therapeutic Indications


    Treatment of erectile dysfunction

    Unlicensed Uses

    Digital ulcers in systemic sclerosis



    50mg to be taken approximately one hour before sexual activity.
    The dose may be increased to 100mg or decreased to 25mg based on efficacy and tolerance. The maximum recommended dose is 100mg. The maximum recommended dosing frequency is once per day.

    Digital ulcers associated with systemic sclerosis (unlicensed)
    25mg three times a day, increasing to 50mg three times a day.

    Patients with Renal Impairment

    Creatinine clearance below 30 ml/minute Initially 25mg, increasing stepwise to 50mg up to 100mg depending on efficacy and tolerance.

    Patients with Hepatic Impairment

    Initially 25mg, increasing stepwise to 50mg up to 100mg depending on efficacy and tolerance.

    Additional Dosage Information

    In order for sildenafil to be effective, sexual stimulation is required.

    If sildenafil is taken with food, the onset of activity may be delayed compared to a fasted state.

    Patients receiving alpha-blocker therapy should be stable before sildenafil is administered to reduce the risk of postural hypotension. A starting dose of 25mg should be considered in these patients.


    Children under 18 years
    Patients in whom sexual activity is inadvisable
    Systolic blood pressure < 90mmHg
    Hereditary degenerative retinal disorder
    History of non-arteritic anterior ischaemic optic neuropathy (NAION)
    Recent cerebrovascular accident
    Recent myocardial infarction
    Severe cardiac failure
    Severe cardiovascular disorder
    Severe hepatic impairment
    Unstable angina

    Precautions and Warnings

    Multiple system atrophy
    Predisposition to priapism
    Risk factors for cardiovascular disorder
    Visual field defects
    Anatomical deformation of penis
    Aortic stenosis
    Cardiovascular disorder
    Cavernosal fibrosis
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Hypertrophic obstructive cardiomyopathy
    Lactose intolerance
    Left ventricular outflow obstruction
    Multiple myeloma
    Peptic ulcer
    Peyronie's disease
    Renal impairment - creatinine clearance below 30 ml/minute
    Sickle cell disease

    Reduce dose in patients with creatinine clearance below 30ml/min
    Reduce dose in patients with hepatic impairment
    Advise ability to drive/operate machinery may be affected by side effects
    Concurrent alpha blockers: only initiate therapy when blood pressure stable
    Some formulations contain lactose
    Pre-treatment medical history and exam. to diagnose erectile dysfunction
    Assess baseline cardiac function prior to treatment
    Cardiovascular events may occur during or shortly after sexual intercourse
    Seek medical advice if priapism does not resolve within 4 hours
    Discontinue if any kind of visual disturbance occurs
    Advise patient not to take St John's wort concurrently
    Advise patients not to take nitrates or amyl nitrite concurrently
    Advise patient grapefruit products may increase plasma level

    Before initiating treatment for erectile dysfunction, patients cardiovascular status should be considered due to the cardiac risk associated with sexual activity. Sildenafil has vasodilator properties resulting in mild and transient decreases in blood pressure. Patients with increased susceptibility to vasodilators include those with left ventricular outflow obstruction (e.g. aortic stenosis, hypertrophic obstructive cardiomyopathy) or those with the rare syndrome of multiple system atrophy manifesting as severely impaired autonomic control of blood pressure.

    Pregnancy and Lactation


    Not indicated for use in women.


    Not indicated for use in women.

    Side Effects

    Angina pectoris
    Arteriosclerotic retinopathy
    Atrial fibrillation
    Blurred vision
    Cerebrovascular accident
    Chest pain
    Colour vision deficiencies
    Conjunctival hyperaemia
    Dry mouth
    Eye disorder
    Eye irritation
    Eye swelling
    Eyelid oedema
    Gastroesophageal reflux
    Hypersensitivity reactions
    Increased heart rate
    Iris disorder
    Lacrimation disorder
    Myocardial infarction
    Nasal congestion
    Nasal dryness
    Nasal oedema
    Non-arteritic anterior ischaemic optic neuropathy (NAION)
    Ocular oedema
    Painful extremities
    Penile haemorrhage
    Prolonged erection
    Reduced visual acuity
    Retinal haemorrhage
    Retinal vein occlusion
    Scleral discolouration
    Stevens-Johnson syndrome
    Sudden cardiac death
    Sudden deafness
    Throat tightness
    Toxic epidermal necrolysis
    Transient ischaemic attack
    Upper abdominal pain
    Ventricular arrhythmias
    Visual disturbances
    Visual field defects
    Visual haloes
    Vitreous floaters


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: June 2019

    Reference Sources

    Summary of Product Characteristics: Aronix 50mg film coated tablets. Dr Reddys. Revised September 2019.

    Summary of Product Characteristics: Liberize (sildenafil) 50mg film-coated tablets. Teva UK limited. Revised February 2021.

    Summary of Product Characteristics: Sildenafil 25mg film coated tablets. Dr Reddys. Revised December 2016.
    Summary of Product Characteristics: Sildenafil 50mg film coated tablets. Dr Reddys. Revised December 2016.
    Summary of Product Characteristics: Sildenafil 100mg film coated tablets. Dr Reddys. Revised December 2016.

    Summary of Product Characteristics: Viagra 25mg, 50mg, 100mg. Pfizer Ltd. Revised May 2019.
    Summary of Product Characteristics: Viagra Connect 50mg. Pfizer Ltd. Revised November 2017.

    Summary of Product Characteristics: Vizarsin 25mg tablets. Consilient health Ltd. Revised March 2013.
    Summary of Product Characteristics: Vizarsin 50mg tablets. Consilient health Ltd. Revised March 2013.
    Summary of Product Characteristics: Vizarsin 100mg tablets. Consilient health Ltd. Revised March 2013.

    Summary of Product Characteristics: Zamantos 50mg film-coated tablets. Crescent Pharma Ltd. Revised October 2019.

    NICE Evidence Services Available at: Last accessed: 08 November 2022

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