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Description
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?
Warning!
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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.
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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.
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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.
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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.
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This medicine should not be taken more than once a day.
Use with caution in
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Elderly men
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Disease involving the heart and blood vessels (cardiovascular disease)
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Obstruction of blood flow out of the heart, eg due to narrowing of the aorta (aortic stenosis)
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Abnormal heart rhythm seen on the heart monitoring trace (ECG) as a 'prolonged QT interval'
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Low blood potassium levels (hypokalaemia)
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Bleeding disorders, eg haemophilia
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Active peptic ulcer
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Physical abnormality of the penis, such as severe curvature, scarring or Peyronie's disease
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Conditions such as sickle cell disease, bone
cancer or leukaemia in which there is an increased risk of prolonged
erections (priapism)
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Decreased kidney function
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Decreased liver function
Not to be used in
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Women
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Children or adolescents under 18 years of age
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Conditions in which sexual activity is not advisable, for example severe heart disorders
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Angina not well controlled by medical treatment (unstable angina)
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People who have had a heart attack in the last six months
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People who have had a stroke in the last six months
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Severe heart failure
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Low blood pressure (hypotension)
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Hereditary degeneration of the back of the eyeball (retina), such as retinitis pigmentosa
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Severe kidney failure requiring dialysis
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Severely decreased liver function
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People taking any form of nitrate medications, eg glyceryl trinitrate
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People taking protease inhibitors to treat HIV infection, eg ritonavir, indinavir.
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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.
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Headache
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Flushing
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Dizziness
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Inflammation of the lining of the nose (rhinitis) causing a blocked or runny nose
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Indigestion (dyspepsia)
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Nausea
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Visual disturbances, such as blurred vision, blue/green tinge to vision, watery eyes
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Sleepiness
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Increased heart rate
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Awareness of your heart beat (palpitations)
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High blood pressure (hypertension)
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Low blood pressure (hypotension)
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Fainting (syncope)
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Shortness of breath
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Nosebleeds
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Abnormal reaction of the skin to light, usually a rash (photosensitivity)
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Pain or increased tension in the muscles
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Prolonged or painful erections
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Anxiety
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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:
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glyceryl trinitrate, isosorbide mononitrate, isosorbide dinitrate, used for angina or heart failure
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nicorandil
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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:
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itraconazole (forms taken by mouth)
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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:
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alfuzosin
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doxazosin
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indoramin
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prazosin
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terazosin.
Vardenafil should be avoided in men who are taking any of the following medicines:
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amiodarone
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procainamide
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quinidine
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sotalol.
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