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Terms Of Use

SILDENAFIL

Brand Name(s) : Viagra, Revatio
Warnings
Uses
Side Effects
Precautions
Interactions
Overdose

SILDENAFIL WARNINGS

Sildenafil should be used in caution with:

It should not be used in:

  • Females (Viagra only)
  • Children (under 18 years of age for Viagra and under 1 year of age for Revatio)
  • Males for whom sexual activity is not advised (e.g. males with severe heart problems or who have recently had a heart attack)
  • People who have low blood pressure
  • People who have had a stroke
  • People with severe liver disease
  • People with rare hereditary galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption
  • People with certain rare inherited eye diseases, such as retinitis pigmentosa
  • People who have ever lost vision due to a condition known as non-arteritic anterior ischaemic optic neuropathy (NAION)
  • People who are allergic to sildenafil or any other ingredients of the medication
  • Men taking other medications for erectile dysfunction
  • People taking any 'nitrate' medication (e.g. glyceryl trinitrate, isosorbide dinitrate, nicorandil used to treat angina)
  • People taking nitric oxide donor medication, such as amyl nitrate ('poppers')
  • People taking the protease inhibitor, ritonavir used to treat HIV
  • People taking ketoconazole or itraconazole (to treat fungal infections) if taking Revatio

Also see list of precautions and interactions

STORAGE

  • Viagra tablets: Do not store above 30°C
  • Revatio tablets: Do not store above 30°C
  • Revatio oral suspension: Store in a refrigerator at 2 to 8°C

SILDENAFIL USES

Sildenafil is used to relax and widen blood vessels.

It is a phosphodiesterase type 5 inhibitor, sometimes known as a PDE5 inhibitor.

It is used to treat males with problems in getting and keeping an erection (erectile dysfunction). It is also used to treat people with raised blood pressure in the lungs (pulmonary arterial hypertension).

In general this drug is used when males fail to achieve or maintain an erect penis required for sexual activity. The medication increases blood flow to the penis and with sexual stimulation, an erect penis can be achieved. It is also used to treat pulmonary arterial hypertension as it decreases blood pressure in the lungs by widening its blood vessels.

Benefits of being on this drug can include an improvement in the level of sexual performance. In people with pulmonary hypertension, benefits can include a reduction in the arterial blood pressure in the lung and an improvement in exercise capacity.

Listed below are the typical uses of sildenafil:

On occasion your doctor may prescribe this medicine to treat a condition not on the above list.

HOW TO USE/TAKE

Sildenafil (Viagra)

  • Take this medication by mouth usually one hour before sexual activity with or without food. If the medication is taken with a heavy meal, it is likely to delay the onset of the drug activity. Use this medication only when required in order to get the most benefit from it. This medication should not be taken more than once a day.

It may take up to 30 minutes before the full benefit of this drug takes effect, but longer if the medication is taken with a meal.

Sildenafil (Revatio)

  • Take this medication by mouth usually three times a day, with or without food. Medication should be taken approximately 6 to 8 hours apart. Use this medication for duration of prescription in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told otherwise by your doctor.
  • It may take up to 12 weeks before the full benefit of this drug takes effect.

Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • This medication is unlikely to affect driving and operating machinery, but dizziness or altered vision may occur with treatment so caution should be taken. People should be aware of how they react to the medication before initiating these activities.
  • The intake of grapefruit juice may result in higher levels of sildenafil in your blood. Hence, taking grapefruit juice with sildenafil is not recommended.

Consult your doctor or pharmacist for more details.

When can I stop?

  • Sildenafil (Viagra)
    Use medication only when required and as prescribed by your doctor.

  • Sildenafil (Revatio)
    It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop. Always complete the full course as prescribed by your doctor. Abruptly stopping your medication may result in your symptoms worsening.

SILDENAFIL SIDE EFFECTS

  • Sildenafil (Viagra)
    • Headache
    • Flushing
    • Vision problems (including problems with colour vision, sensitivity to light, blurred vision or sharpness of vision)
    • Indigestion
    • Stuffy nose
    • Dizziness
    • Eye problems (including eye pain, bleeding at the back of the eye and bloodshot eyes)
    • Nausea and vomiting
    • Sleepiness
    • Reduced sense of touch
    • Skin rash
    • Dry mouth
    • Muscle pain
    • Irregular or rapid heartbeat
    • Vertigo
    • Ringing in the ears
    • Tiredness
  • Sildenafil (Revatio)
    • Headache
    • Flushing
    • Diarrhoea
    • Indigestion
    • Eye and vision problems
    • Pain in arms and/or legs)
    • Stuffy nose
    • Infections (e.g. influenza, bronchitis)
    • Cough
    • Migraine
    • Reduced sense of touch
    • Tingling sensation (pins and needles)
    • Muscle pain
    • Difficulty in getting and/or staying asleep
    • Nose bleeds
    • Hair loss
    • Dry mouth
    • Vertigo
    • Back pain
    • Anaemia
If any of these persist or you consider them severe then inform doctor or pharmacist.

Tell your doctor immediately if you develop any of the following symptoms:

  • Prolonged or painful erection, which lasts continually for more than 4 hours
  • Chest pain. If you get chest pains during or after sexual intercourse, get in a semi-sitting position and try to relax and do not use nitrates to treat your chest pain.
  • Decrease or loss of vision. Stop taking the medication and immediately inform your doctor.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.

SILDENAFIL PRECAUTIONS

Before taking sildenafil, tell your doctor or pharmacist if you are allergic to it; or to other phosphodiesterase type 5 inhibitors; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have:

  • Severe heart or liver problems
  • Recently had a heart attack
  • Severe liver disease
  • Had a stroke or have low blood pressure
  • Lost vision due to non-arteritic anterior ischaemic optic neuropathy (NAION)
  • Rare hereditary galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption
  • Any rare inherited eye diseases, such as retinitis pigmentosa
  • Allergic to sildenafil or any other ingredients of Viagra/ Revatio.

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following:

  • Heart or circulation problems
  • Any deformities in the penis (e.g. angulation, Peyronie's disease)
  • Sickle cell anaemia (disorder of the red blood cells), multiple myeloma (cancer of the bone marrow) or leukaemia (cancer of the white blood cells)
  • Stomach ulcers
  • Bleeding problems
  • Severe pulmonary arterial hypertension

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • Sildenafil (Viagra)
    Drinking alcohol can temporarily impair your ability to get an erection. To get the maximum benefit from your medicine, you are advised not to drink excessive amounts of alcohol before taking it.
  • Sildenafil (Revatio)
    Alcohol is not known to affect sildenafil.

Pregnancy and breastfeeding - please ensure you read the detailed information below

PREGNANCY

  • Sildenafil (Viagra)
Medication is not indicated for use by women.

  • Sildenafil (Revatio)
The safety of sildenafil has not been established during pregnancy. Therefore sildenafil is not safe to take if you are, or are planning to become, pregnant. Ask your doctor or pharmacist if you have any doubts or questions about this.

It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.

BREAST FEEDING

  • Sildenafil (Viagra)
This medication is not indicated for use by women.

  • Sildenafil (Revatio)
It is not known whether sildenafil passes into breast milk. The manufacturer therefore states that it should not be taken if you are breastfeeding.

It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.

SILDENAFIL INTERACTIONS

Before using this medicine, tell your prescriber of all the medicines you are taking including prescription medicines and medicines you have bought over the counter without a prescription. Tell your prescriber if you are taking vitamins or complementary remedies such as herbal products, as these can also interact with medicines.

If you are taking more than one medicine, these may interact with each other. Your prescriber may decide to use medicines which interact with each other if the benefit outweighs the risks. In these cases, the dose of your medicines may need to be adjusted or you may be monitored more closely.

The following medicines may interact with sildenafil:

  • Any nitrate medication including nicorandil, usually used for the relief of angina pectoris (or chest pain)
  • Nitric oxide donor medication, such as amyl nitrate ('poppers')
  • Ritonavir used to treat HIV
  • Other medication for erectile dysfunction
  • Riociguat
  • Amlodipine used to treat high blood pressure and angina
  • Alpha-blockers such as doxazosin to treat high blood pressure or prostate enlargement
  • Protease inhibitors, such as saquinavir used to treat HIV
  • Erythomycin, clarithromycin and telithromycin (antibiotics)
  • Ketoconazole, itraconazole (antifungals)
  • Cimetidine (for intestinal problems)

  • Carbamazepine and phenytoin used to treat epilepsy
  • Rifampicin used to treat infections including tuberculosis
  • Phenobarbital used to treat epilepsy and as a sedative
  • This information does not contain all possible interactions. Therefore, tell your prescriber of all the products you are using before taking this medicine.

    If you have a question or want to discuss anything about your medicine, speak to your local pharmacist.

    SILDENAFIL OVERDOSE

    If you take more medication than you should you may experience an increase in side effects and their severity.

    If you think you, or someone you care for, might have accidentally taken more than the recommended dose of sildenafil or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.

    MISSED DOSE

    • Sildenafil (Viagra)
    Medication is taken as required one hour before sexual activity. Medication should not be taken more than once a day.

    • Sildenafil (Revatio)
    If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

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    Source: Selected from data included with permission and copyrighted by Boots UK Limited. This copyrighted material is sourced from a licensed data provider and is not for distribution, except as may be authorised by the applicable terms of use.
    CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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