Levitra

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How does it work?

Levitra tablets contain the active ingredient vardenafil, which is a medicine used in the treatment of erectile dysfunction (impotence). Vardenafil is called a phosphodiesterase type 5 inhibitor, and works by preventing the action of a chemical in the body called phosphodiesterase type 5.

An erection is produced via a complex chain of events, involving signals from the nervous system and the release of chemical messengers within the tissues of the penis. One of these chemical messengers is called cyclic GMP.

Cyclic GMP causes the blood vessels in the penis to widen by relaxing a thin layer of muscle found in the blood vessel walls. This allows more blood to enter the penis, which ultimately results in the penis becoming rigid and erect.

Cyclic GMP is normally broken down by another chemical in the body called phosphodiesterase type 5. Vardenafil works by preventing the action of phosphodiesterase type 5, thus stopping the breakdown of cyclic GMP. This means that the blood vessels are kept dilated for longer, improving blood flow to the penis and maintaining an erection.

As vardenafil enhances the actions of the chemical messengers responsible for producing an erection, it will only work once these messengers are present. This means that sexual stimulation is required for it to produce and maintain an erection. The dose should be taken approximately 25 minutes to one hour before intended intercourse, and it may produce an erection in response to sexual stimulation up to five hours after taking the dose.

What is it used for?

- Impotence (erectile dysfunction)

Warning!

- This medicine may be taken with or without food, but its onset of action may be delayed if it is taken with a meal high in fat.
- Unless your doctor or pharmacist tells you otherwise, you should avoid drinking grapefruit juice while taking this medicine, as it may increase the level of this medicine in your blood and hence increase the risk of side effects.
- If your erection lasts longer than 4 hours (priapism), consult a doctor immediately. Treatment of this condition should not be delayed more than 6 hours, as this can cause damage to the erectile tissue in the penis and irreversible erectile dysfunction.
- This medicine may cause dizziness and visual disturbances. You should make sure you are aware of your reactions to this medicine before driving or operating machinery.
- This medicine should not be taken more than once a day.

Use with caution in

- Elderly men
- Disease involving the heart and blood vessels
- Obstruction of blood flow out of the heart, eg due to narrowing of the aorta (aortic stenosis)
- Abnormal heart rhythm seen on the heart monitoring trace (ECG) as a 'prolonged QT interval'
- Low blood potassium levels (hypokalaemia)
- Bleeding disorders, eg haemophilia
- Active peptic ulcer
- Physical abnormality of the penis, such as severe curvature, scarring or Peyronie's disease
- Conditions such as sickle cell disease, bone cancer or leukaemia in which there is an increased risk of prolonged erections (priapism)
- Decreased kidney function
- Decreased liver function

Not to be used in

- Women
- Children or adolescents under 18 years of age
- Conditions in which sexual activity is not advisable, for example severe heart disorders
- Angina not well controlled by medical treatment
- People who have had a heart attack in the last six months
- People who have had a stroke in the last six months
- Severe heart failure
- Low blood pressure (hypotension)
- Hereditary degeneration of the back of the eyeball (retina), such as retinitis pigmentosa
- Severe kidney failure requiring dialysis
- Severely decreased liver function
- People taking any form of nitrate medications, eg glyceryl trinitrate
- People taking protease inhibitors to treat HIV infection, eg ritonavir, indinavir.
- This medicine is not recommended for people who have ever experienced an eye condition called non-arteritic anterior ischemic optic neuropathy (NAION). This condition causes a sudden, partial decrease or loss of vision in one or both eyes due to damage to the optic nerve. It can be temporary or permanent. Talk to your doctor if you have ever experienced this.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine.

Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

- Headache
- Flushing
- Dizziness
- Inflammation of the lining of the nose (rhinitis) causing a blocked or runny nose
- Indigestion (dyspepsia)
- Nausea
- Visual disturbances, such as blurred vision, blue/green tinge to vision, watery eyes
- Sleepiness
- Increased heart rate
- Awareness of your heart beat (palpitations)
- High blood pressure (hypertension)
- Low blood pressure (hypotension)
- Fainting (syncope)
- Shortness of breath
- Nosebleeds
- Abnormal reaction of the skin to light, usually a rash (photosensitivity)
- Pain or increased tension in the muscles
- Prolonged or painful erections
- Anxiety
- Chest pain

The side effects listed above may not include all of the side effects reported by the drug's manufacturer. . For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start taking this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

Vardenafil must not be taken with any form of nitrate medication, as this combination may potentially produce a severe drop in blood pressure. Nitrate medications include the following:

- glyceryl trinitrate, isosorbide mononitrate, isosorbide dinitrate, used for angina or heart failure
- nicorandil
- amyl nitrate (also known as 'poppers').

Vardenafil must not be taken with medicines called protease inhibitors that are used to treat HIV infection, for example ritonavir and indinavir, as these can cause the blood level of vardenafil to rise very high, thus increasing the risk of side effects.

Vardenafil should not be taken in combination with other treatments for erectile dysfunction.

If you are taking the antibiotic erythromycin you should not take more than 5mg of vardenafil in 24 hours.

Men who are older than 75 years of age must not take vardenafil if they are taking any of the following medicines, as these medicines can cause the blood level of vardenafil to rise very high. Younger men taking any of these medicines should also avoid vardenafil:

- itraconazole (forms taken by mouth)
- ketoconazole (forms taken by mouth).

If vardenafil is taken with medicines called alpha-blockers, which are used for high blood pressure or an enlarged prostate gland, the combination may cause a drop in blood pressure that may result in dizziness or fainting in some men.

Vardenafil may be taken by men who are stabilised on alpha-blocker medicines, but the maximum dose of vardenafil should not exceed 5mg, and the dose of vardenafil should not be taken within six hours of taking the alpha-blocker. Alpha-blockers include the following:

- alfuzosin
- doxazosin
- indoramin
- prazosin
- terazosin.

Vardenafil should be avoided in men who are taking any of the following medicines:

- amiodarone
- procainamide
- quinidine
- sotalol.

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