Generic Viagra

Generic Viagra (Sildenafil citrate) is a pharmacy drug designated to relieve the symptoms of ED; generic Viagra is taken per os. Sildenafil, the drug’s active component, has no efficacy if the function is normal and cannot be activate in case of the absence of sexually stimulating irritators. The drug is not supposed to be used in such subcategories as females and persons under the age of 18.

Sildenafil citrate as a newly discovered substance was patented by Pfizer in the beginning of 90s and approved by FDA in 1998. During the following decade and a half Viagra was available only in form of drug produced by the original manufacturer, due to the validity of patent. As of recently, sildenafil became available as a considerably cheaper generic Viagra with efficacy and safety identical to those of the original drug.

The active component of generic Viagra, sildenafil citrate, belongs to the class called scientifically phosphodiesterase type 5 inhibitors with specificity for cyclic GMP), much more effective in promoting penile vasodilation than other selective inhibitors. The effect of sildenafil is completely absent in a denervated penis and is antagonized by substances that inhibit NO synthase. This shows that Viagra is able to enhance a function that must be partially present. It cannot replace a erogenous stimulus, nor can it transform into a stimulus that is not a stimulus. It does not replace the pudenda innervation, but enhances its function if it is lacking. It does not act except in the presence of a vascular system sensitive to NO. It makes no sense to prescribe it against the background of a normal organ function. Not elective in hypogonadism impotence. It is useless in patients with reduced or lack of libido, but not with erection (subjects who have normal and complete erections during the phases of REM sleep, but who do not feel sexual desire: or for psychiatric diseases – typically major depression – or medication – typically certain antidepressants, certain diuretics, etc., or, simply because such individuals do not experiencel any attraction to a certain partner).

The advisability of administering if pharmacologically induced ED is suspected should be cautiously evaluated. In this circumstance, the prescriber of sildenafil must take into consideration: the diagnosis underlying the treatment in progress, the drug’s principles of action and possible interactions of the active substance with other substances administered concomitantly. All these aspects are difficult to evaluate as there is currently no reference literature.

It is interesting to note that the cavernous tissue contains not only PDE5, but also PDE3, inhibited by cyclic GMP, and PDE4 specific for cyclic AMP. PDE3 is selectively inhibited by amrinone and milrinone and plays an important role in the vasodilation that produces erection. It could be the mediator of the sympathetic stimulation erection: in this case the mechanism involved would certainly be beta-adrenergic. Milrinone is effective in vitro and in vivo in vasodilating human cavernous tissue and in producing erection in men.

The pills of Generic Viagra are film-coated tablets of blue color and are shaped like a diamond. Other attributes are subject to variation and differ from one manufacturer to another.

The onset of Generic Viagra effects takes 30 to 60 minutes and depends on the way the drug is administered. For instance, abundant meals or meals with high content of fat partially inhibit and slow down the onset of sildenafil action, and so does alcohol. Taken on an empty stomach, Generic Viagra produces effect faster and more intensely.

Sildenafil half-life duration is 3 to 5 hours, which means that Generic Viagra stays in the body for the same amount of time. Sildenafil has affinity for retinal PDE, which is activated by photons (ie by light stimuli), and catabolizes the cyclic GMP that stabilizes retinal neurons, thus controlling their threshold of stimulation. This PDE, initially classified as PDE5 – but more recently distinguished as PDE6 as retinal – is reduced in certain forms of retinal degeneration, such as retinitis pigmentosa. For this reason, Generic Viagra is contraindicated in these clinical forms.

The efficacy of sildenafil on erection is dose-dependent and should be evaluated for each patient. For most individuals the starting dose of 50 mg is recommended, to be taken possibly an hour before sexual activity (however, from half an hour to 4 hours before). Based on efficacy and tolerability, the dose can be reduced to 25 mg or increased to 100 mg. The maximal dose of sildenafil that can be taken safely is 100 mg.

In the elderly, following a reduction in the clearance of sildenafil, there may be an increase in plasma levels of the drug, so it is advisable to use the 25 mg dose (possibly to be increased with caution based on efficacy and tolerability).

Sildenafil should be used no more than once a day.

The most feared side effect during sildenafil use is the risk of hypotension. Sildenafil does not selectively inhibit the PDE-V of pudendi vessels, but also that of other vascular and non-vascular districts. The PDE-V is also present in pulmonary vessels and other body districts, so taking viagra may result in a slight decrease in systemic pressure. The nitrates producing vasodilat NO and their effect is enhanced by definition by sildenafil, with sometimes unforeseeable, sometimes lethal consequences. The use of sildenafil is therefore absolutely contraindicated in combination with nitrates, in the short or long duration of action, in whatever form they are administered (transdermal, sublingual, inhalation, injectable: see list). Several cases of death following the use of Generic Viagra occurred in patients who used organic nitrates or who were given trinitrin because during intercourse they had suffered precordial pain due to coronary insufficiency.

For this reason, the prescription of Generic Viagra to cardiac patients or other risk factors, for which sexual activity is not recommended, should be prohibited.

Finally, the use of sildenafil is contraindicated in the following groups of patients with particular pathologies, as under such conditions its safety has not been investigated so far: severe hepatic or renal insufficiency, subjects with arterial pressure below 90/50 mmHg, recent history of stroke or myocardial infarction.

Finally, sildenafil is contraindicated in case of hypersensitivity to the active ingredient or to the excipients present in the tablet (cellulose, calcium hydrogen phosphate, croscaramellose sodium, magnesium stearate, hypromellose, titanium dioxide or E171, lactose, triacetin, aluminum lacquer containing indigo carmine or E132 ).

Sildenafil causes mild and transient reductions in blood pressure that, in most cases, do not translate into clinical effects (see: contraindications). The use of sildenafil by patients treated with HP medications, including alpha- and beta-blockers, ACE inhibitors, diuretics, etc. does not seem to cause particular risks of hypotensive crisis.

Generic Viagra should not be used in patients receiving HIV / AIDS treatment with antiviral drugs like ritonavir and other drugs from this class.

Do not use Generic Viagra with antifungal drugs like ketoconazole.

Safety and efficacy of sildenafil in combination with other treatments of erectile dysfunction have not been tested, so associations of this type are to be excluded.

Diagnosis of erectile dysfunction

It is advisable to carry out a short history and an objective examination in order to diagnose erectile dysfunction, determine the underlying causes of the disease and decide on the most appropriate treatment.

Cardiovascular conditions

Since there is a certain degree of risk associated with sexual activity, the cardiovascular conditions of the patient must be evaluated before starting the treatment of erectile dysfunction.

Penile deformation / priapism

Sildenafil should be used with maximal attention in persons with genetic penile deformity, such as Peyronie’s disease, fibrosis or angulation and in patients with diseases predisposing to priapism (diseases of blood cells).

Hemorrhagic disorders

There is no information on the safety of sildenafil in patients with bleeding disorders or with active peptic ulcer, and therefore the drug should be used in such patients with great caution.

Use in subjects whose activity requires particular attention

Those taking sildenafil must be informed that among the undesirable effects, episodes of dizziness and visual disturbances are also reported, conditions that can negatively affect the ability to drive or carry out activities that require particular attention.

Generic Viagra AnalogsGeneric Viagra Analogs

• Caverta – Ranbaxy Laboratories Ltd.
• Edegra – Sun Pharma Laboratories Ltd
• Eriacta – Ranbaxy Laboratories Ltd.
• Instarise – Macleods Pharmaceuticals Pvt. Ltd.
• Manforce – Mankind Pharmaceuticals Ltd.
• Nizagara – Uni-Sule Private Ltd.
• Omnigra – Cipla Ltd.
• Penegra – Ajanta Pharma
• Progra – Cipla Ltd.
• Sidnakind – Mankind Pharmaceuticals Ltd.
• Spegra – Emcure Pharmaceuticals Ltd.
• Viagra – Pfizer
• Viraha – Micro Labs Ltd.
• Zenegra – Alkem Laboratories Ltd.