| Levitra
Information |
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How
effective is Levitra in treating impotence?
What
is the appropriate dose of Levitra?
Similar
to Viagra can individuals buy a larger dose of Levitra and then split
the dose?
Why
is Levitra sometimes called Vardenafil HCL?
Which
pharmaceutical company manufactures Levitra?
Is
Levitra an effective treatment option for erectile dysfunction following
prostate surgery?
What is the mechanism of action of Levitra?
Is
there a generic version of Levitra?
Will
I have a spontaneous erection after I take Levitra?
Does
Levitra help with erectile dysfunction related depression?
Should I eat prior to taking Levitra?
Why
should individuals not drink grapefruit juice while taking Levitra?
In
addition to the active ingredients, what other componenets make up Levitra?
What
are the most common side effects associated with the use of Levitra?
Are
there any drug interactions associated with the use of Levitra?
Why
should Levitra not be used if an individual is taking Nitrates?
Why
should Levitra not be used if an individual is taking Alpha-blockers?
Are
there individuals that should not take Levitra?
Will
Levitra produce an erection for hours?
Can
I take Levitra if I have preexisting cardiovascular complications?
Does
Levitra provide any protection against sexually transmitted diseases?
Should
individuals drive a vehicle or operate heavy machinery while taking
Levitra?
How effective is Levitra in treating impotence?
Recent reports release by Bayer the manufacturer of Levitra report some
ninety percent of men taking Levitra report improved erections. In addition,
Levitra consistently improved rates of penetration and hardness, as
well as, success with intercourse in a broad population of men with
erectile dysfunction (impotence).
What is the appropriate dose of Levitra?
Currently, Levitra is available in 2.5mg, 5mg, 10mg, and 20mg doses.
The standard dose is to take an initial dose of 10mg. This dose is decreased
for various medical conditions (liver conditions, end stage renal disease,
hypo tension, cardiovascular disease, taking other medications, etc.)
and increased up to 20mg if the standard dose is not effective in healthy
individuals. Men over the age of 65 years will often take a lower dose.
Similar to any prescription medication, consult with a physician prior
to taking Levitra. The medication is usually taken 25 - 60 minutes prior
to sexual activity. If you overdose on Levitra seek immediate medical
attention.
Similar to Viagra can individuals buy a larger
dose of Levitra and then split the dose?
Yes, individuals can buy the 20mg Levitra tablets and then split the
dose into the standard dose of 10mg. Some individuals split the 20mg
tablets into fourths and just take 5mg of Levitra. Individuals should
not take more than 20mg of Levitra at any time.
Why is Levitra sometimes called Vardenafil HCL?
Levitra is the brand name and Vardenafil HCL is the generic name for
the medication.
Which pharmaceutical company manufactures Levitra?
Levitra is manufactured by the Bayer corporation in Germany and will
subsequently be distributed and marketed by GlaxoSmithKline.
Is Levitra an effective treatment option for
erectile dysfunction following prostate surgery?
Levitra is extremely effective in treating erectile dysfunction (impotence)
following prostate cancer surgery. Some 71% of men who had undergone
prostate removal reported significant improvements in erections with
Levrita (20mg) versus 12 per cent in men taking placebo (sugar pill).
The study concluded that this was an important finding for Levitra,
as erectile dysfunction (impotence) following prostate surgery is usually
common.
What is the mechanism of action of Levitra?
Levitra is a new class of medication to help men with erectile dysfunction
(impotence). Viagra was the first of the so called, "PDE-5 inhibitors"
and Levitra is known in the same class to significantly help individuals
treat their erectile dysfunction (impotence). Similar to Viagra, Levitra
increases the quantity of blood supplied to the penis thus improving
the erection. Levitra is very selective in inhibiting the PDE-5 without
affecting other isoenzymes. This allows a smaller dose of Levitra to
have a more pronounced effect as a larger dose of Viagra (the standard
dose of Levitra dose is 10mg while the standard dose of Viagra dose
is 50mg). Through this action, smooth muscle in the penis remains relaxed
for a longer period. This allows for increased blood flow into the cavernous
tissue of the penis thereby generating an erection. Levitra is unique
in that it increases a natural occurring process, therefore, only through
sexual stimulation will an erection occur.
More specifically,
Penile erection is a haemodynamic process. During sexual stimulation,
nitric oxide is subsequently released. The nitric acid activates an
enzyme guanylate cyclase, resulting in an increased level of cyclic
guanosine monophosphate (cGMP) in the corpus cavernosum of the penis.
This results in smooth muscle relaxation in the penis, allowing increased
inflow of blood into the penis. The level of cGMP is regulated by the
rate of synthesis via guanylate cyclase and by the rate of degradation
via cGMP hydrolysing phosphodiesterases (PDEs).
Levitra is a potent
and selective inhibitor of the cGMP specific phosphodiesterase type
5 (PDE5), the most prominent PDE in the human corpus cavernosum. Levitra
enhances the effect of endogenous nitric oxide in the corpus cavernosum
by inhibiting PDE5. When nitric oxide is released secondary to sexual
stimulation, inhibition of PDE5 by Levitra results in increased corpus
cavernosum levels of cGMP. Sexual stimulation is required for Levitra
to produce its beneficial therapeutic effects.
Is there a generic version of Levitra?
Levitra is still under the patent of Bayer/GlaxoSmithKline which have
the exclusive rights to market Levitra. Some companies may advertise
a generic version of Levitra, however, this medication is not approved
or tested by the FDA or European regulators so you cannot be sure of
the purity and/or quality of the medication.
Will I have a spontaneous erection after I take
Levitra?
No, men still need some form of sexual stimulation in order to achieve
an erection.
Does Levitra help with erectile dysfunction related
depression?
Yes, studies have shown that Levitra is effective in treating the depressive
symptoms experienced by men with erectile dysfunction (impotence). These
studies showed men taking Levitra reported improved erections and fewer
depressive symptoms than those men taking a placebo (sugar pill).
Should I eat prior to taking Levitra?
Individuals can take Levitra with or without food, however, preferably
not following a heavy or a meal high in fat content. In addition, individuals
should not take Levitra with grapefruit juice, remember excessive alcohol
can result in erectile dysfunction (impotence).
Why should individuals not drink grapefruit juice
while taking Levitra?
Grapefruit juice being a weak inhibitor of CYP3A4 gut wall metabolism,
may give rise to modest increases in plasma levels of Levitra.
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In addition to the active ingredients, what other
components make up Levitra?
In addition to the active ingredient, vardenafil HCl, each tablet contains
colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose,
titanium dioxide, crospovidone, hypromellose, polyethylene glycol, yellow
ferric oxide, and red ferric oxide.
What are the most common side effects associated
with the use of Levitra?
The most common side effects associated with the use of Levitra include
the following: headache, flushing, dyspepsia, nausea and rhinitis. Most
of the reported adverse reactions were mild and stopped when the individual
discontinued the medication.
Uncommon side effects
associated with taking Levitra (these may affect less than 1 in 100
people) included the following:
- Sensitivity of
the eye to sunlight
- High or low blood
pressure
- Fainting
- Stiffness in
muscles
- Effects on vision
Are there any drug interactions associated with
the use of Levitra?
Studies in human liver microsomes showed that Levitra is metabolized
primarily by cytochrome P450 (CYP) isoforms 3A4/5, and to a lesser degree
by CYP 2C9. Therefore, inhibitors of these enzymes are expected to reduce
Levitra clearance.
Cytochrome
P450 Inhibitors:
- Cimetidine:
(400 mg b.i.d.) had no effect on vardenafil bioavailability (AUC)
and maximum concentration (Cmax) of vardenafil when co-administered
with 20 mg LEVITRA in healthy volunteers.
- Ketoconazole:
(200 mg once daily) produced a 10-fold increase in vardenafil AUC
and a 4-fold increase in Cmax when co-administered with Levitra (5
mg) in healthy volunteers. A 5-mg Levitra dose should not be exceeded
when used in combination with 200 mg once daily ketoconazole. Since
higher doses of ketoconazole (400 mg daily) may result in higher increases
in Cmax and AUC, a single 2.5 mg dose of Levitra should not be exceeded
in a 24-hour period when used in combination with ketoconazole 400
mg daily.
- Erythromycin:
(500 mg t.i.d) produced a 4-fold increase in vardenafil AUCand a 3-fold
increase in Cmax when co-administered with Levitra 5 mg in healthy
volunteers It is recommended not to exceed a single 5 mg dose of Levitra
in a 24-hour period when used in combination with erythromycin.
HIV Protease
Inhibitors:
Ritonavir
and Indinavir: Upon concomitant administration
of 5 mg of Levitra with 600 mg BID ritonavir, the Cmax and AUC of ritonavir
were reduced by approximately 20%. Upon administration of 10 mg of Levitra
with 800 mg TID indinavir , the Cmax and AUC of indinavir were reduced
by 40% and 30%, respectively.
The interaction
is a consequence of blocking hepatic metabolism of vardenafil by ritonavir,
a highly potent CYP3A4 inhibitor, which also inhibits CYP2C9. Ritonavir
significantly prolonged the half-life of vardenafil to 26 hours. Consequently,
it is recommended not to exceed a single 2.5 mg Levitra dose in a 72-hour
period when used in combination with ritonavir.
Additional
Drug Interactions:
Alpha-blockers:
When Levitra 10 or 20 mg was given to healthy volunteers either simultaneously
or 6 hours after a 10 mg dose of Terazosin, significant hypotension
developed in a substantial number of subjects. With simultaneous dosing
of Levitra 10 mg and Terazosin 10 mg, 6 of 8 subjects experienced a
standing systolic blood pressure of less than 85 mm Hg. With simultaneous
dosing of Levitra 20 mg and terazosin 10 mg, 2 of 9 subjects experienced
a standing systolic blood pressure of less than 85 mm Hg. When Levitra
dosing was separated from Terazosin 10 mg by 6 hours, 7 of 28 subjects
who received 20 mg of Levitra experienced a decrease in standing systolic
blood pressure below 85 mm Hg. In a similar study with Tamsulosin in
healthy volunteers, 1 of 24 subjects dosed with Levitra 20 mg and Tamsulosin
0.4 mg separated by 6 hours experienced a standing systolic blood pressure
below 85 mm Hg. Two of 16 subjects dosed simultaneously with Levitra
10 mg and Tamsulosin 0.4 mg experienced a standing systolic blood pressure
below 85 mm Hg. The administration of lower doses of Levitra
with alpha blockers has not been completely evaluated to determine if
they can be safely administered together. Based on these data, Levitra
should not be used in patients on alpha-blocker therapy.
Nitrates:
The blood pressure lowering effects of sublingual nitrates (0.4 mg)
taken 1 and 4 hours after vardenafil and increases in heart rate when
taken at 1, 4 and 8 hours were potentiated by a 20 mg dose of Levitra
in healthy middle-aged subjects. These effects were not observed when
Levitra 20 mg was taken 24 hours before the NTG. Potentiation of the
hypotensive effects of nitrates for patients with ischemic heart disease
has not been evaluated, and concomitant use of Levitra and nitrates
is contraindicated.
Nifedipine:
Vardenafil 20 mg, when co-administered with slow-release Nifedipine
30 mg or 60 mg once daily, did not affect the relative bioavailability
(AUC) or maximum concentration (Cmax) of nifedipine, a drug that is
metabolized via CYP3A4. Nifedipine did not alter the plasma levels of
Levitra when taken in combination. In these patients whose hypertension
was controlled with Nifedipine, Levitra 20 mg produced mean additional
supine systolic/diastolic blood pressure reductions of 6/5 mm Hg compared
to placebo.
Alcohol:
Alcohol (0.5 g/kg body weight: approximately 40 mL of absolute alcohol
in a 70 kg person) and vardenafil plasma levels were not altered when
dosed simultaneously. Levitra (20 mg) did not potentiate the hypotensive
effects of alcohol during the 4-hour observation period in healthy volunteers
when administered with alcohol (0.5 g/kg body weight).
Aspirin:
Levitra (10 mg and 20 mg) did not potentate the increase in bleeding
time caused by aspirin (two 81 mg tablets).
Other interactions:
Levitra had no effect on the pharmacodynamics of Glyburide (glucose
and insulin concentrations) and warfarin (prothrombin time or other
pharmacodynamic parameters).
In addition, no
pharmacokinetic interactions were observed between Vardenafil and the
following drugs: Maalox, Glyburide, Warfarin, Digoxin, and Ranitidine.
In the Warfarin study, Vardenafil had no effect on the Prothrombin time
or other pharmacodynamic parameters.
Why should Levitra not be used if an individual
is taking Nitrates?
Individuals should be counseled that concomitant use of Levitra with
nitrates could cause blood pressure to suddenly drop to an unsafe level,
resulting in dizziness, syncope, or even a stroke or heart attack.
Why should Levitra not be used if an individual
is taking Alpha-blockers?
Physicians should inform their patients that concomitant use of Levitra
with alpha-blockers is contraindicated because co-administration can
produce hypotension that could increase the work load of the heart to
potentially dangerous levels.
Are there individuals that should not take Levitra?
Yes, there are some patient subgroups that have not been studied in
clinical trials. Therefore, the use of Levitra is not recommended in
the following patients until further studies are completed: or until
an individuals physician has approved the use of the medication:
- Unstable angina
- Severe hepatic
impairment (Child-Pugh C)
- End stage renal
disease requiring dialysis
- Known hereditary
degenerative retinal disorders, including retinitis pigmentosa
- Hypotension (resting
systolic blood pressure of <90 mm Hg)
- Uncontrolled
hypertension (>170/110 mm Hg)
- Recent history
of stroke, life-threatening arrhythmia, or myocardial infarction (within
the last 6 months); severe cardiac failure
- If you have an
allergy (if you're hypersensitive) to vardenafil or any of the other
ingredients of Levitra.
- If you are taking
other medications (consult with your physician)
- Cardiovascular
complications (stroke, arrhythmia, heart attack, etc.)
- Degenerative
eye disease i.e. retinitis pigmentosa
Additional
caution should be used in the following individuals:
- Individuals with
a physical condition affecting the shape of the penis (i.e. angulation,
Peyronie's disease and cavernosal fibrosis, etc.).
- Individuals with
an illness that can cause priapism or sustained erections (i.e. sickle
cell disease, multiple myeloma and leukemia, etc.).
- Individuals that
have stomach ulcers (i.e. gastric or peptic ulcers).
- Individuals with
a bleeding disorder (i.e. haemophilia).
- Individuals that
are using any other treatments for erection difficulties (i.e. Viagra,
Cialis).
Will Levitra produce an erection for hours?
Levitra only enhances a man's natural ability to achieve an erection
when you are sexually stimulated. Erections should end following an
orgasm or the end of stimulation. In the rare case your erection should
lasts for more than 4 hours, please seek immediate medical attention.
Can I take Levitra if I have preexisting cardiovascular
complications?
No, some individuals should not take Levitra with preexisting medical
conditions. Physicians should discuss with patients the potential cardiac
risk of sexual activity for patients with preexisting cardiovascular
risk factors.
Does Levitra provide any protection against sexually
transmitted diseases?
No, the use of Levitra offers no protection against sexually transmitted
diseases.
Should individuals drive a vehicle or operate
heavy machinery while taking Levitra?
Levitra may cause some people to feel dizzy or have an alteration in
there vision. These individuals should not drive or operate heavy machinery
while taking Levitra.
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