[49][51] Without sexual stimulation, and therefore lack of activation of the NO/cGMP system, sildenafil should not cause an erection.

Side Effect Frequency (%) Severity Level Advice
Headache 35 Mild Analgesics recommended
Flushing 25 Mild Hydration advised
Nasal Congestion 15 Mild Decongestants may help
Dizziness 10 Moderate Avoid driving until stable
Vision Changes 5 Mild Seek medical advice if persistent

Other drugs that operate by the same mechanism include tadalafil (Cialis) and vardenafil (Levitra).

Mechanism of action

The primary indication of sildenafil is treatment of erectile dysfunction (inability to sustain a satisfactory erection to complete sexual intercourse). Its use is now one of the standard treatments for erectile dysfunction, including for males with diabetes mellitus. Tentative evidence suggests that sildenafil may help males who experience antidepressant-induced erectile dysfunction. While sildenafil improves some markers of disease in people with pulmonary arterial hypertension, it does not appear to affect the risk of death or serious side effects. Sildenafil and other PDE5 inhibitors are used off-label to alleviate vasospasm and treat severe ischemia and ulcers in fingers and toes for people with secondary Raynaud's phenomenon;[9][21] these drugs have moderate efficacy for reducing the frequency and duration of vasospastic episodes.

What is sildenafil used for?

[9] As of 2016,[update] their role more generally in Raynaud's was not clear. Sildenafil has shown some potential for improving exercise performance at high altitudes. However, its overall efficacy is not clear. Sildenafil has been studied for high-altitude pulmonary edema (HAPE), but its use is currently not recommended for that indication. In clinical trials, the most common adverse effects of sildenafil use included headache, flushing, indigestion, nasal congestion, and impaired vision, including photophobia and blurred vision. Sildenafil is broken down in the liver by hepatic metabolism using cytochrome p450

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enzymes, mainly CYP450 3A4 (major route), but also by CYP2C9 (minor route) hepatic isoenzymes.

Brand Viagra Marketed in the USA is Made in Europe

Those using protease inhibitors are recommended to limit their use of sildenafil to no more than one 25 mg dose every 48 hours. [4] Other drugs that interfere with the metabolism of sildenafil include erythromycin and cimetidine, both of which can also lead to prolonged plasma half-life levels. The use of sildenafil and an α1 blocker (typically prescribed for hypertension or for urologic conditions, such as benign prostatic hypertrophy) at the same time may lead to low blood pressure, but this effect does not occur if they are taken at least 4 hours apart. Concomitant use of nitric oxide donors, organic nitrites and nitrates,[30] such as: nitroglycerinisosorbide mononitrateisosorbide dinitratesodium nitroprussidealkyl nitrites (commonly known as "poppers") Concomitant use of soluble guanylyl cyclase stimulators, such as riociguat Sildenafil should not be used if sexual activity is inadvisable due to underlying cardiovascular risk factors. Sildenafil's popularity with young adults has increased over the years.

What should I know about sildenafil before taking it?

[32] Sildenafil's brand name, Viagra, is widely recognized in popular culture, and the drug's association with treating erectile dysfunction has led to its recreational use. [33] The reasons behind such use include the belief that the drug increases libido, improves sexual performance,[33] or permanently increases penis size. [34] Studies on the effects of sildenafil when used recreationally are limited, but suggest it has little effect when used by those who do not have erectile dysfunction. In one study, a 25 mg dose was shown to cause no significant viagra over the counter change in erectile quality, but did reduce the postejaculatory refractory time. [35] This study also noted a significant placebo effect in the control group. The major product of metabolisation by these enzymes is N-desmethylated sildenafil, which is metabolised further.

Adverse effects

Unprescribed recreational use of sildenafil and other PDE5 inhibitors is noted as particularly high among users of illegal drugs. [36] Sildenafil is sometimes used to counteract the effects of other substances, often illicit. [33] Some users mix it with methylenedioxymethamphetamine (MDMA, ecstasy), other stimulants, or opiates in an attempt to compensate for the common side effect of erectile dysfunction, a combination known as "sextasy", "rockin' and rollin'", "hammerheading", or "trail mix". [33] Mixing it with amyl nitrite, another vasodilator, is particularly dangerous and potentially fatal. The 2007 Ig Nobel Prize in aviation went to Patricia V.

Altitude sickness

Agostino, Santiago A. Plano, and Diego A. Golombek of Universidad Nacional de Quilmes, Argentina, for their discovery that sildenafil helps treat jet lag recovery in hamsters. Professional athletes have been documented using sildenafil, believing the opening of their blood vessels will enrich their muscles. In turn, they believe it will enhance their performances. This metabolite also has an affinity for the PDE receptors, about 40% of that of sildenafil.

  • Indian pharmaceutical firms boast high-quality manufacturing under GMP standards.
  • Viagra is often combined with other ED medications for enhanced efficacy in India.
  • The sale of Viagra online in India has expanded rapidly over the last decade.
  • Some Indian brands of Viagra are available in 25mg, 50mg, and 100mg strengths.
  • The drug is generally safe for most men, but must be avoided with certain health conditions.
  • In India, purchasing Viagra without a prescription is common but not always recommended.
  • The global demand for Indian-made Viagra has increased due to its affordability.
  • Viagra's patent expired in India, allowing widespread manufacturing of generics.
  • The Indian government regulates the sale of sildenafil-based medications for safety.
  • Patients are advised to avoid alcohol and fatty foods with Viagra to improve absorption.

Thus, the metabolite is responsible for about 20% of sildenafil's action.

  • Sildenafil was originally developed by Pfizer and later produced generically in India.
  • Indian companies hold a significant share of the global sildenafil market.
  • Male age group most commonly using Viagra in India ranges from 40 to 60 years.
  • Viagra’s effects typically last 4 to 6 hours, depending on individual health.
  • The Indian pharmaceutical industry exports sildenafil-based medicines to over 150 countries.
  • Some Indian brands produce extra-fast-acting Viagra formulations.
  • The World Health Organization recognizes Indian sildenafil drugs as safe when approved.
  • Education about proper Viagra use is increasing through Indian health campaigns.
  • Pharmacovigilance systems monitor adverse effects of Viagra in the Indian population.
  • Research continues into improving bioavailability and reducing side effects of Viagra.

Sildenafil is excreted as metabolites predominantly in the feces (about 80% of administered oral dose) and to a lesser extent in the urine (around 13% of the administered oral dose).

Medical uses

Acetildenafil and other synthetic structural analogs of sildenafil which are PDE5 inhibitors have been found as adulterants in a number of "herbal" aphrodisiac products sold over-the-counter. [41] These analogs have not undergone any of the rigorous testing that drugs like sildenafil have passed, and thus have unknown side-effect profiles. [42] Some attempts have been made to ban these drugs, but progress has been slow so far, as, even in those jurisdictions that have laws targeting designer drugs, the laws are drafted to ban analogs of illegal drugs of abuse, rather than analogs of prescription medicines. However, at least one court case has resulted in a product being taken off the market. The US Food and Drug Administration (FDA) has banned numerous products claiming to be Eurycoma longifolia that, in fact, contain only analogs of sildenafil.

Recreational use

[44][45][46] Sellers of such fake herbals typically respond by just changing the names of their products. Sildenafil and/or N-desmethylsildenafil, its major active metabolite, may be quantified in plasma, serum, or whole blood to assess pharmacokinetic status in those receiving the drug therapeutically, to confirm the diagnosis in potential poisoning victims, or to assist in the forensic investigation in a case of fatal overdose. Nitric oxide (NO) in the corpus cavernosum of the penis binds to guanylate cyclase receptors, which results in increased levels of cGMP, leading to smooth muscle relaxation (vasodilation) of the intimal cushions of the helicine arteries. This smooth muscle relaxation leads to vasodilation and increased inflow of blood into the spongy tissue of the penis, causing an erection. [49] Robert F. If taken with a high-fat meal, absorption is reduced; the time taken to reach the maximum

Chemical synthesis

Furchgott, Ferid Murad, and Louis Ignarro won the Nobel Prize in Physiology or Medicine in 1998 for their independent study of the metabolic pathway of nitric oxide in smooth muscle vasodilation. The molecular mechanism of smooth muscle relaxation involves the enzyme CGMP-dependent protein kinase, also known as PKG. This kinase is activated by cGMP and it phosphorylates multiple targets in the smooth muscle cells, namely myosin light chain phosphatase, RhoA, IP3 receptor, phospholipase C, and others. [50] Overall, this results in a decrease in intracellular calcium and desensitizing proteins to the effects of calcium, engendering smooth muscle relaxation. The molecular structure of sildenafil is similar to that of cGMP and acts as a competitive binding agent of PDE5 in the corpus cavernosum, resulting in more cGMP and increased penile response to sexual stimulation. plasma concentration increases by around one hour, and the maximum concentration itself is decreased by nearly one-third.

Method Description Effectiveness Rating Popularity (%)
Herbal Remedies Using herbs like Ashwagandha Moderate 30
Yoga and Meditation Stress reduction and focus Variable 45
Acupuncture Needle therapy for circulation Limited 10
Ayurvedic Medicines Herbal formulations from Ayurveda Varies 15

When taken orally, sildenafil for erectile dysfunction results in an average time

  • The decline in erectile function can be due to lifestyle or underlying health conditions.
  • In India, ED is sometimes linked to stress, diabetes, or hypertension.
  • Viagra's approval process in India involves rigorous clinical trials.
  • Indian market users report high satisfaction with affordable generic Viagra.
  • The birth of online telemedicine services has made Viagra consultations easier in India.
  • Many Indian clinics offer follow-up services for patients on ED treatments.
  • Awareness programs aim to dispel myths surrounding erectile dysfunction and Viagra.
  • Some Indian men combine Viagra with herbal supplements for enhanced effect.
  • Legal regulations require proper labeling and packaging of sildenafil medications.
  • The stigma around sexual health in India is gradually decreasing thanks to education.

to onset of erections of 27 minutes (ranging from 12 to 70 minutes).

Year Estimated Sales (Million USD) Market Share (%) Growth Rate (%)
2020 120 15 5
2021 135 16 12
2022 150 17 11
2023 165 18 10

Sublingual use of sildenafil for erectile dysfunction results in an average onset

Viagra® (Sildenafil) Manufactured by Weefsel Pharma

[4] Some sildenafil users have complained of seeing everything tinted blue (cyanopsia). [24] This cyanopsia can be explained because sildenafil, while selective for PDE5, does have some affinity for PDE6, which is the phosphodiesterase found in the retina. Patients thus taking the drug may experience colorvision abnormalities. Some complained of blurriness and loss of peripheral vision. In July 2005, the US Food and Drug Administration (FDA) updated labeling for tadalafil (Cialis), vardenafil (Levitra), and sildenafil (Viagra) to reflect a small number of post-marketing reports of sudden vision loss, while acknowledging that "...it is not possible to determine whether these oral medicines for erectile dysfunction were the cause of the loss of eyesight or whether the problem is related to other factors such as high blood pressure or diabetes, or to a combination of these problems.

What are the most common side effects of sildenafil?

"[25] A careful review of pooled data from clinical trials containing well documented information about the dose and duration of exposure to the drug for a large number of patients, yields no evidence for an increased risk of non-arteritic anterior ischemic optic neuropathy or other adverse ocular events associated with PDE5 inhibitor use. Rare but serious adverse effects found through postmarketing surveillance include prolonged erections, severe low blood pressure, myocardial infarction (heart attack), ventricular arrhythmias, stroke, increased intraocular pressure, and sudden hearing loss. [4] In October 2007, the FDA announced that the labeling for all PDE5 inhibitors, including sildenafil, required a more prominent warning of the potential risk of sudden hearing loss. Care should be exercised by people who are also taking protease inhibitors for the treatment of HIV infection. Protease inhibitors inhibit the metabolism of sildenafil, effectively multiplying the plasma levels of sildenafil, increasing the incidence and severity of side effects. of action of 15 minutes and lasting for an average of 40 minutes.

  • Viagra is a popular medication used to treat erectile dysfunction in men.
  • In India, Viagra is available both by prescription and over-the-counter in some areas.
  • The active ingredient in Viagra is sildenafil citrate, which helps increase blood flow to the penis.
  • Indian pharmaceutical companies manufacture generic versions of Viagra at lower costs.
  • Buying Viagra online from reputable Indian pharmacies offers convenience and affordability.
  • It is important to consult a doctor before using Viagra to ensure safety and proper dosage.
  • Common side effects of Viagra include headaches, dizziness, flushing, and nasal congestion.
  • Viagra should be taken about an hour before sexual activity for optimal results.
  • Indian regulations require Sildenafil products to meet safety standards for sale and distribution.
  • Use of Viagra is not recommended for individuals taking nitrate medications.