Sildenafil Tablets
Order Consultation for Erectile Dysfunction Treatment






Sildenafil is the active ingredient in Viagra. It is available as a generic erectile dysfunction treatment and it is a prescription-only medication.
To place an order, fill in our brief medical questionnaire. You can choose a preferred treatment, such as Sildenafil, Viagra, Cialis or Levitra.
One of our doctors will check if the medication is suitable for you and issue your prescription to a local pharmacy in Ireland or your home address.
A consultation for erectile dysfunction treatment prescription costs €20.



About Sildenafil Tablets
-
-
Sildenafil is used to treat both erectile dysfunction and pulmonary arterial hypertension (PAH). It is the active ingredient in Viagra. Sildenafil is a prescription medication, meaning that it is only available on prescription and should be taken exactly as prescribed to be fully effective.
-
-
Sildenafil is the active ingredient in Viagra. It causes the release of nitrous oxide (NO), a chemical that enlarges the blood vessels in the penis during sexual stimulation. This allows for the necessary inflow of blood needed to cause an erection.
Sildenafil tablets come in 25mg, 50mg and 100mg doses. The dosage you need to take will depend on your age, gender, medical condition, your response to therapy and use of any interacting medication.
The recommended dose for most people is 50mg taken between 30 minutes and four hours prior to sexual activity. This dose can be increased to 100mg or decreased to 25mg depending on adverse effects and efficacy.
Ideally, it should be taken on an empty stomach. If you take Sildenafil after eating, it may take longer to start working. Your tablet should be swallowed whole with a drink of water. Sildenafil should not be taken more than once in a day.
Drinking grapefruit juice while using this medication can be dangerous. It may increase the drug's concentration in your blood, causing more pronounced Sildenafil side effects.
Patients in the following groups should take 25mg Sildenafil tablets:
- anyone over 65 years of age
- with liver failure
- with kidney problems
- using potent cytochrome P450 inhibitors medicines
-
-
The only difference between Sildenafil and Viagra is the branding and packaging of the medication. Viagra is the brand name for the generic medicine, called Sildenafil.
In June 2013, Pfizer’s patent for Viagra expired, opening a market for generic Sildenafil citrate. As a result, people now have a choice between branded Viagra and more affordable generic Sildenafil tablets.
Sildenafil and Viagra are ‘medically equivalent’, meaning they both work in the same way, and contain the same active ingredients.
-
-
Sildenafil is used to treat erectile dysfunction, when used alongside sexual stimulation. Sildenafil treats erectile dysfunction by relaxing the blood vessels in your penis, which allows the blood flow to increase. Good blood flow to the penis is necessary for a strong and healthy erection.
Sildenafil is not an aphrodisiac. It will not make you sexually stimulated or raise your libido on its own.
-
-
Always take your medication exactly as prescribed to you by your doctor.
As a rule, you should take sildenafil tablets up to 1 hour before having sex. Swallow your sildenafil tablets whole, without chewing or crushing them. You can take your sildenafil tablets with or without water.
Sildenafil works best on an empty stomach. It may not be as effective immediately after eating a heavy, high-fat meal.
-
-
You can drink up to 2-3 units of alcohol, safely, while taking sildenafil. Many people find that alcohol helps them overcome their anxieties around sex.
However, too much alcohol can make erectile dysfunction problems worse. Drinking more than 2-3 units daily might have a negative effect on your sexual function.
-
-
When using Sildenafil, you may experience one or more of the following common side effects:
- dizziness/ light-headedness
- headache
- flushing
- heartburn or indigestion
- nosebleeds or nasal congestion
- trouble sleeping
- oedema (swollen hands, ankles or feet)
- visual disturbances (blurred vision/ increased sensitivity to light/ blue-green colour blindness)
If any Sildenafil side effects worsen over time or are particularly uncomfortable, consult your doctor or pharmacist.
If you experience any of the following serious side effects during sex and you already have heart problems, stop taking Sildenafil and get medical help.
- severe dizziness
- fainting
- chest/ jaw/ left arm pain
- nausea
If you experience any of the following side effects, it indicates that an allergic reaction has occurred, and you should seek medical attention immediately:
- rash
- itching/ swelling (particularly of the face, tongue and throat)
- severe dizziness
- trouble breathing
If you experience a sudden loss of hearing in one or both ears, or a ringing in your ears while using Sildenafil tablets, speak to your doctor.
If you experience a sudden loss of eyesight in one or both eyes, stop taking the medication and consult a healthcare professional immediately. This is a very rare Sildenafil side effect, although your chances of experiencing it increases if you already suffer from any of the following:
- heart disease
- diabetes
- high cholesterol
- high blood pressure
- existing eye problems
- you are over 50
- you are a smoker
-
-
Whether taking Sildenafil 100mg, 50mg or 25mg, you should keep a list of all other medications you take (including prescription/ non-prescription and herbal medication) and share it with your doctor or pharmacist.
Do not start, stop or change your Sildenafil tablets without first discussing it with your doctor. Sildenafil must not be taken with any form of nitrate medication as this combination can produce a severe drop in blood pressure that can cause dizziness, fainting, or even a heart attack.
The following medications could interact negatively with Sildenafil:
- nitrate medications (Glyceryl trinitrate, isosorbide mononitrate and isosorbide dinitrate nicorandil)
- amyl nitrate 'poppers'
- alpha blockers (doxazosin, prazosin, terazosin)
- HIV drugs (ritonavir, saquinavir, delavirdine)
- St John's Wort
- cimetidine
- anticonvulsants (carbamazepine, phenobarbital, phenytoin)
- azole antifungals
- macrolide antibiotics (erythromycin)
-
-
You should not start taking Sildenafil tablets without first consulting your doctor or pharmacist. Inform them of your full medical history, including if you have any of the following conditions:
- sickle cell disease
- high or low blood pressure
- dehydration
- priapism (painful erection problems)
- eye problems (such as blurred or loss of vision in one or both eyes)
- heart problems (arrythmia, angina, heart attack, aortic stenosis)
- kidney disease
- liver disease
- fluid in the lungs
- problems with the shape of the penis (angulation, fibrosis/scarring)
- stroke in the past 6 months
A common Sildenafil side effect is loss of vision or bouts of dizziness, therefore do not drive, operate machinery or engage in any task that requires intense concentration or alertness until you are sure you are not experiencing these side effects. Limit alcohol intake when using Sildenafil tablets.
If you are a woman using Sildenafil (Revatio) you should avoid pregnancy. During pregnancy, Sildenafil should only be taken when there is a clear need, and it has been prescribed by a doctor. Discuss the risks and benefits with your doctor. It is not known whether this medication passes into breast milk, so consult your doctor before breast feeding.
The elderly should take this medication with caution as its effects can be more pronounced. If your erection lasts longer than four hours, consult a doctor immediately as this may cause permanent damage to your penis.

GMC: 6149061

IMC Number: 429637

GMC: 7155722
Zava offers a convenient and discreet service to help men improve their erectile dysfunction. There are a number of treatments you can consider. Continue to our erectile dysfunction service page to learn about the treatment options available.