|
What
physically happens?
Our penis includes two long tubes of
spongy tissue. When the brain is sexually stimulated, nerve
endings release nitric oxide, which in turn increases the synthesis
of a protein called cyclic guanosine monophosphate, or cGMP.
The cGMP relaxes smooth muscles, allowing the spongy tubes to
fill with blood.
When filled, the tubes press veins closed, maintaining the erection.
Eventually, an enzyme called Phosphodiesterase type 5 (PDE5)
breaks down the cGMP and the erection collapses or shrinks.
How the drug works?
Levitra inhibits Phosphodiesterase-5 or PDE-5 in the same tendency
as Viagra. This allows smooth blood flow towards Penis and helps
you remain in the activity for longer duration.
Consumption pattern!
Levitra needs to be consumed about
25-60 minutes before you are ready for sexual encounter. Within
an estimated span of 30 minutes, Levitra begins its effect. This
single pill has the tendency to remain potent for up to 12-hours.
In any condition, we recommend you to consult your physician
to ensure any ill-effect of Levitra.
Is it right to use ED drugs?
Yes! The clinical condition
of Erectile Dysfunction supports the usage of various ED drugs
available in the market. Unless one encounter some major side
effects on the usage of these drugs - drugs
like Levitra are quite safe to use. Anyhow - they are produced
under strict clinical condition and minimize the counter effects
chances. And in whichever country they are available - it's only
after strict approval from the concerned authorities i.e. the
parent drug regulation authority.
But the problem should be very much physical. Impotency sometime
is also caused due to the some psychological factor. In such
a situation these drugs may not work. They may counter react
as well.
And in brief......
» Levitra diffuses PDE-5 enzymes and increase the blood
flow into the Penis
» Levitra clinically produced a success rate of 95%
» Levitra starts affecting
within 12-16 minutes after consumption and remains effective
for up to four hours
» Levitra tends to develop
some side-effects like headache, nausea and aching but not necessarily
» We recommend you to consult your physician before prescribing
to Levitra
» Store Levitra at
some cool and dry and never expose direct sunlight. Prefer
a drawer or cupboard
Pharmacokinetic properties
• Absorption
Vardenafil is rapidly absorbed with maximum observed plasma
concentrations reached in some men as early as 15 minutes after
oral administration. However, 90% of the time, maximum plasma
concentrations are reached within 30 to 120 minutes (median 60
minutes) of oral dosing in the fasted state. The mean absolute
oral bioavailability is 15 %. After oral dosing of vardenafil
AUC and Cmax increase almost dose proportionally over the recommended
dose range (5 - 20 mg).
When vardenafil is taken with a high fat meal (containing 57%
fat), the rate of absorption is reduced, with an increase in
the median tmax of 1 hour and a mean reduction in Cmax of 20%.
Vardenafil AUC is not affected. After a meal containing 30% fat,
the rate and extent of absorption of vardenafil (tmax, Cmax and
AUC) are unchanged compared to administration under fasting conditions.
Distribution
The mean steady state volume of distribution
for vardenafil is 208 l, indicating distribution into the tissues.
Vardenafil and its major circulating metabolite (M1) are highly
bound to plasma proteins (approximately 95% for vardenafil or
M1). For vardenafil as well as M1, protein binding is independent
of total drug concentrations.
Based on measurements of vardenafil in semen of healthy subjects
90 minutes after dosing, not more than 0.00012% of the administered
dose may appear in the semen of patients.
Metabolism
Vardenafil is metabolised predominantly by
hepatic metabolism via cytochrome P450 (CYP) isoform 3A4 with
some contribution from CYP3A5 and CYP2C isoforms.
In humans the one major circulating metabolite (M1) results
from desethylation of vardenafil and is subject to further metabolism
with a plasma elimination half life of approximately 4 hours.
Parts of M1 are in the form of the glucuronide in systemic circulation.
Metabolite M1 shows a phosphodiesterase selectivity profile similar
to vardenafil and an in vitro potency for phosphodiesterase type
5 of approximately 28% compared to vardenafil, resulting in an
efficacy contribution of about 7%.
Elimination
The total body clearance of vardenafil is
56 l/h with a resultant terminal half life of approximately 4-5
hours. After oral administration, vardenafil is excreted as metabolites
predominantly in the faeces (approximately 91-95% of the administered
dose) and to a lesser extent in the urine (approximately 2-6%
of the administered dose).
Pharmacokinetics in special patient groups
Elderly
Hepatic clearance of vardenafil in healthy
elderly volunteers (65 years and over) was reduced as compared
to healthy younger volunteers (18 - 45 years). On average elderly
males had a 52% higher AUC, and a 34% higher Cmax than younger
males.
Renal insufficiency
In volunteers with mild to moderate
renal impairment (creatinine clearance 30 - 80 ml/min), the pharmacokinetics
of vardenafil were similar to that of a normal renal function
control group. In volunteers with severe renal impairment (creatinine
clearance < 30
ml/min) the mean AUC was increased by 21% and the mean Cmax
decreased by 23%, compared to volunteers with no renal impairment.
No statistically significant correlation was observed between
creatinine clearance and vardenafil exposure (AUC and Cmax).
Vardenafil pharmacokinetics have not been studied in patients
requiring dialysis.
• Hepatic insufficiency
In patients with mild to moderate hepatic impairment (Child-Pugh
A and B), the clearance of vardenafil was reduced in proportion
to the degree of hepatic impairment. In patients with mild hepatic
impairment (Child-Pugh A), the mean AUC and Cmax increased 17%
and 22% respectively, compared to healthy control subjects. In
patients with moderate impairment (Child-Pugh B), the mean AUC
and Cmax increased 160% and 133% respectively, compared to healthy
control subjects (see Section 4.2). The pharmacokinetics of vardenafil
in patients with severely impaired hepatic function (Child-Pugh
C) have not been studied.
PHARMACEUTICAL PARTICULARS
List of excipients
One Tablet of Levitra Contains :
Crospovidone,Magnesium Stearate Microcrystalline Cellulose Silica,
colloidal anhydrous.
Film coat is made of Macrogol 400,Hypromellose,
Titanium dioxide (E171),Ferric oxide yellow (E172) and Ferric oxide red (E172)
Incompatibilities : Not applicable.
Shelf life : 3 years
Special precautions for storage : No special precautions
for storage.
Nature and contents of container : PP/Aluminium foil
blisters in cartons of 2, 4, 8 and 12 tablets. Not all pack sizes
may be marketed.
Instructions for use and handling : No special requirements.
SOURCE: www.levitra.co.uk
|
