Levitra (vardenafil) tablets are available in strengths of:

    - 5 mg of vardenafil (5.926 mg of vardenafil hydrochloride trihydrate)
    - 10 mg of vardenafil (11.852 mg of vardenafil hydrochloride trihydrate)
    - 20 mg of vardenafil (23.705 mg of vardenafil hydrochloride trihydrate).

Besides the active ingredient, Levitra (vardenafil) tablets also contain the following excipients: crospovidone, magnesium stearate, microcrystalline cellulose, colloidal anhydrous silica, macrogol 400, hypromellose, titanium dioxide, iron oxide yellow, iron oxide red.

USAGE:

The haemodynamic process of erecting a penis is grounded in the relaxation of smooth muscle in the corpus cavernosum and its allied arterioles. Nitric Oxide is released from the corpus cavernosum's nerve ends during sexual arousal. This triggers the enxyme guanylate cyclase causing the corpus cavernosum's cyclic guanosine monophosphate levels to increase. This is what causes relaxation in the smooth muscle and allows freer blood flow into the penis, causing an erect penis. The rate of degradation via cGCP hydrolyzing phosphodiesterases  and the rate of synthesis via the guanylate cyclase are the two factors that actually regulates the cGMP level. The cGMP specific phosphodiesterase type 5 (PDE5) is the main PDE in the corpus cavernosum of a human.
Levitra (vardenafil) powerfully improves the effect of endogenous Nitric Oxide, which the corpus cavernosum unleashes during sexual arousal, by regulating PDE5. PDE5 is the enzyme that causes cGMP degradation in the corpus caverosum. The levels of cGMP are boosted in the corpus as a result of the PDE5 inhibition, causing smooth muscle relaxation and freer blood flow to the corpus cavernosum. This is how Levitra (vardenafil) creates the potential for men to respond naturally to sexual stimulation.

Quantitative analysis, outside of a living organism, display Levitra (vardenafil) as a selective inhibitor of PDE5.
Levitra (vardenafil) gives the conscious rabbit an erect penis, but it depends on endogenous nitric oxide synthesis and is potentiate by nitric oxide donors.
Vardenafil is rapidly absorbed after oral administration. Cmax is reached as early as 15 minutes, in 90% of the time Cmax is reached within 30 to 120 minutes (median 60 minutes) of oral dosing in the fasted state.
There is extensive first-pass metabolism of Levitra (vardenafil) resulting in considerable inter-subject and intra-subject variability in the observed pharmacokinetic parameters. The mean absolute bioavailability is approximately 15% after a 10 mg dose. After oral dosing of Levitra (vardenafil), AUC and Cmax increase almost dose proportionally over the recommended dose range (5 mg to 20 mg).
When Levitra (vardenafil) was taken with a high fat meal (~57% fat), the rate of absorption (mean Cmax) was reduced by approximately 20%, median Tmax was delayed by approximately 1 hour, and mean AUC was not affected. After a 'normal meal' (~30% fat) pharmacokinetic parameters were not significantly affected. Based on these results Levitra (vardenafil) can be taken with or without food.

SIDE EFFECTS:

In a clinical, worldwide, trial, vardenafil was issued to more than 4000 patients. More than 750 patients received treatment for one year or more. For most patients the drug was well tolerated, and the nature of any adverse reactions were usually temporary and mild to moderate.
Adverse Event:  of  Levitra (vardenafil)
any event     57.6%   
headache     15.6%    
flushing     11.7%    
rhinitis     10.3%    
dyspepsia     3.9%    
accidental injury     3.2%   
sinusitis     3.1%    
flu syndrome     2.7%    
nausea     2.3%    
dizziness     2.4%    
increased creatine kinase     2.0%    
arthralgia     2.0%    

These are dose dependant rate of adverse reactions to the drugs.