Erectile Dysfunction (PDE5 Inhibitor)


Uses


What is Erectile Dysfunction (PDE5 Inhibitor) for?

What is erectile dysfunction (ED)?

    ED is the consistent or recurrent difficulty to achieve or sustain a firm erection or duration for satisfactory sexual intercourse. Many men have dealt with or are dealing with erectile dysfunction.

    Causes of ED include physical trauma, chronic diseases (such as high blood pressure and diabetes), side effects of some medications, excessive alcohol intake, smoking, and psychological factors.

    Various treatment options are available for ED, depending on its causes. This leaflet covers only oral medications named Sildenafil and Tadalafil.

What are Sildenafil and Tadalafil?

    Sildenafil and Tadalafil belong to a class of medications called phosphodiesterase type 5 inhibitors or PDE5 inhibitors. They treat ED by relaxing muscles found in the walls of blood vessels and increasing arterial blood flow at the penis, leading to penile erection.

    An erection will not occur just by taking Sildenafil or Tadalafil. They can help you achieve an erection only if you are sexually stimulated.

How should I take or use Erectile Dysfunction (PDE5 Inhibitor)?

  • If you are taking SILDENAFIL:
    • Take Sildenafil on a when-needed basis, half an hour to one hour (up to 4 hours) before sexual activity.
    • Sildenafil may be taken with or without food; however it may take longer to start working if taken with a high-fat meal.
    • Do not take more than the dose prescribed to you.
    • Do not take Sildenafil more than once a day.
  • If you are taking TADALAFIL on a WHEN-NEEDED basis:
    • Take Tadalafil at least half an hour (up to 36 hours) before sexual activity.
    • Tadalafil may be taken with or without food.
    • Do not take more than the dose prescribed to you.
    • Do not take Tadalafil more than once a day.
    • The recommended dose of Tadalafil when taken as needed is higher than the recommended dose when taken once daily. Avoid taking Tadalafil at when-needed doses continuously every day.
  • If you are taking TADALAFIL on a ONCE-DAILY basis:
    • Take Tadalafil at around the same time of the day, regardless of the timing of sexual activity.
    • Tadalafil may be taken with or without food.
    • If you miss a dose, take the missed dose as soon as you remember. However, if it is time for the next dose, skip the missed dose and take the next dose as scheduled. Do not double your dose to make up for a missed dose.
    • Do not take more than the dose prescribed to you.

What should I do if I forget to take or use Erectile Dysfunction (PDE5 Inhibitor)?

If you are taking TADALAFIL on a ONCE-DAILY basis:

  • If you miss a dose, take the missed dose as soon as you remember. However, if it is time for the next dose, skip the missed dose and take the next dose as scheduled. Do not double your dose to make up for a missed dose.


Precaution


What precautions should I take when taking or using Erectile Dysfunction (PDE5 Inhibitor)?

Inform your healthcare providers if you are:

  • allergic to Sildenafil or Tadalafil.
  • ï‚·
  • taking medicatios called “nitrates” (e.g. glyceryl trinitrate, isosorbide mononitrate, isosorbide dinitrate) which are used to treat angina (or “chest pain”). Do not take Sildenafil or Tadalafil together with a nitrate, as the combination may lead to a dangerous drop in your blood pressure. If you are on a nitrate (whether long-term or as-needed), discuss with your doctor or pharmacist on whether Sildenafil or Tadalafil is safe for you.
  • ï‚·
  • are already taking Sildenafil or Tadalafil for other medical conditions.

Also inform your doctor or pharmacist of any other medical conditions that you may have, and of any other long-term medication that you are taking (including supplements, herbal or traditional medication).


Side Effects


What are some common side effects of Erectile Dysfunction (PDE5 Inhibitor)?

Side effects common to both Sildenafil and Tadalafil:

  • Headache

Side effects more common with Sildenafil:

  • Flushing – symptoms include a sudden feeling of heat in your face or upper body
  • Abnormal vision – symptoms include a blue tinge to vision, blurred vision, or visual disturbance.

Side effects more common with Tadalafil:

  • Stomach upset; acid reflux
  • Back pain; muscle ache
  • Blocked nose

Most side-effects are transient (goes away over time as the medication wears off), and generally of mild to moderate severity.

If you experience any of the following uncommon or rare but serious side effects, STOP and seek medical help IMMEDIATELY:

  • An allergic reaction
  • Symptoms include rash, hives, itching; swelling of the eyelids, face, lips, tongue or throat; sudden wheezing or difficulty in breathing. ï‚·
  • Chest pain
  • If this occurs during intercourse, get in a semi-sitting position to try to relax. Do not use a nitrate to treat your chest pain, as the combination may lead to a dangerous drop in your blood pressure. 
  • Prolonged (lasts for more than 4 hours) and sometimes painful erections
  • Sudden decrease or loss of vision
  • Seizures or fits

If you have any concerns regarding the side effects of Sildenafil or Tadalafil, discuss with your doctor or pharmacist.


Handling


How should I store Erectile Dysfunction (PDE5 Inhibitor)?

  • Keep away from children
  • Keep in a cool, dry place, away from direct sunlight
  • Store at room temperature
  • Store at room temperature (at or below 25-30°C) in the original package, away from sunlight and moist. Keep out of reach of children.

For more information


What else should I know about Erectile Dysfunction (PDE5 Inhibitor)?

  • Not all patients may experience benefit from Sildenafil or Tadalafil the first time they take them. Some may take at least 6 tries before they experience benefit. If you experience no benefit from Sildenafil or Taladafil at the prescribed doses after at least 6 tries and while sexually stimulated, speak to your doctor or pharmacist. ï‚·
  • In order to get the maximum benefit from Sildenafil or Tadalafil, taking them with excessive amounts of alcohol should be avoided.
  • ï‚·
  • Smoking cessation, reducing alcohol intake, losing excess weight and increasing physical activity may improve ED. Talk to your doctor or pharmacist for more information.


Other Languages


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Erectile Dysfunction (PDE5 Inhibitor) in Mandarin Chinese

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Disclaimers

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System, and SingHealth), community pharmacies (Guardian, Unity, and Watsons), and the Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last Updated on December 2016



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