Viagra: What It Is, Uses, Side Effects & Drug Interactions

As men age, the likelihood of erectile dysfunction (ED) becomes more common.

At age 40, around about 4 in 10 men may struggle with ED. This number climbs to nearly 70% by the time they reach 70 years old, according to the Cleveland Clinic. Complete ED -- the total inability to get or maintain an erection -- rises from 5% at age 40 to 15% at age 70.

This article will explore Viagra (sildenafil), a prescription-only medication designed to combat ED. Discover what Viagra is, its purposes, how it functions, potential side effects, drug interactions to be aware of and how it compares to Cialis, another prescription drug for ED.

What is Viagra?

Viagra is a brand name for the drug sildenafil. It is primarily prescribed for treating ED. ED is when a man struggles to achieve or maintain an erection during sexual activity, often called impotence, according to the U.S. National Library of Medicine.

Viagra works by enhancing blood circulation to the penis, but only when there's sexual stimulation. This boost in blood flow triggers the potential for an erection, helping men with ED regain their ability to engage in satisfying sexual experiences.

What is Viagra used for?

Although Viagra is used to treat pulmonary hypertension, a lung condition, its chief application is tackling impotence.

During sexual stimulation, a man's body typically triggers an increase in blood flow to the penis, which results in an erection. Viagra regulates an enzyme, effectively maintaining an erection after sexual stimulation. Without physical stimulation to the penis, like during sexual intercourse, however, Sildenafil won't initiate an erection, the Mayo Clinic explains. Its effectiveness hinges on the presence of sexual arousal and activity.

Sildenafil also helps individuals with pulmonary arterial hypertension (PAH) by relaxing the blood vessels in the lungs. This relaxation facilitates smoother blood flow through the pulmonary vessels, making it easier for the heart to pump blood to the lungs.

What does Viagra do?

When a man is sexually stimulated, Viagra facilitates increased blood flow to the penis, making it erect and firm. This enhanced blood circulation allows men with ED to get and keep an erection during sex.

Viagra acts in response to sexual stimulation, enhancing the natural physiological process that leads to an erection, but it doesn't initiate it without arousal.

How does Viagra work?

Viagra works by inhibiting an enzyme in the body known as PDE5, short for phosphodiesterase type 5. This enzyme breaks down crucial chemicals involved in the erection process.

When Viagra blocks PDE5, these chemicals remain unaltered, keeping the tissues in the penis relaxed and capable of holding an increased volume of blood. This combination of effects results in a firmer and longer-lasting erection during sexual stimulation.

How long does it take for Viagra to work?

The onset of Viagra's effects can vary among individuals and is influenced by factors like dosage and overall health. Viagra typically takes effect for erectile dysfunction within about 30 minutes.

It's important to remember that Viagra should be taken as directed by a health care professional, and individual response times may slightly differ.

How long does Viagra last?

Viagra's effectiveness typically extends up to four hours, with its peak impact occurring within the first two hours. Viagra continues to be active beyond two hours, but its effects may diminish somewhat.

This window allows individuals a substantial time frame to engage in sexual activity, offering flexibility and maintaining a satisfying and fulfilling experience.

Cialis vs. Viagra: What’s the difference?

Cialis (tadalafil) and Viagra (sildenafil) share a fundamental similarity in their mode of action as both are classified as PDE5 inhibitors. This means they impede the action of the phosphodiesterase type 5 enzyme in the body. Consequently, both medications take about 30 to 60 minutes to initiate their effects, aiding patients in achieving the expected erection.

Sildenafil remains effective for about four to six hours, as the Urologic Surgeons of Washington indicates. In contrast, tadalafil extends its efficacy to 36 hours after ingestion. This prolonged duration is particularly beneficial for younger patients or those with milder forms of ED.

It's important to understand that neither drug increases desire; rather, they enhance the quality of erection when the desire for sexual activity is already present.

Viagra dosage

When using the Viagra pill to address erectile dysfunction, the Mayo Clinic explains that the recommended oral dosage may vary depending on age:

• Adults up to 65 years of age: Typically, a single dose of 50 milligrams (mg) is advised, to be taken no more than once a day. You should take it about 1 hour before engaging in sexual intercourse. The medication can be taken between 30 minutes to 4 hours before sexual activity.
• Adults 65 and older: For this age group, a lower dose of 25 mg is recommended, with the same frequency limitations as above. Again, it's essential to take the pill either 1 hour before sexual intercourse or between 30 minutes to 4 hours before the anticipated sexual activity.

Viagra side effects

As with any medication, Viagra (sildenafil) can potentially cause side effects. The National Health Service in England notes that common side effects are reported in more than 1 in 100 people who use this medication.

If you take Viagra for short-term treatment of erection problems, you are less likely to experience side effects since it's a temporary use.

However, if you're using sildenafil for pulmonary hypertension, you might encounter side effects such as headaches, nausea, flushing (including hot flushes), indigestion, stuffy nose or dizziness. These effects are relatively common but manageable.

Viagra drug interactions

Sildenafil, available as Viagra for erectile dysfunction and Revatio for pulmonary hypertension, can interact with various medications and even some beverages. These interactions are essential to be aware of for your safety and the effectiveness of treatment.

Potential drug interactions with sildenafil include:

• Nitrates: Combining sildenafil with nitrates (often used for chest pain) can lead to a dangerous drop in blood pressure.
• Alpha blockers: When used together, sildenafil and alpha-blockers (for blood pressure or prostate issues) may also cause a significant decrease in blood pressure.
• Blood pressure medications: Certain blood pressure medications, when taken alongside sildenafil, may intensify their effects, potentially leading to hypotension (low blood pressure).
• Alcohol: Excessive alcohol consumption while taking sildenafil can increase the risk of side effects and reduce effectiveness.
• Medications affecting liver proteins: Drugs like ritonavir (Norvir), clarithromycin and ketoconazole can affect the breakdown of sildenafil in the body, potentially altering its effectiveness or causing side effects.
• Grapefruit juice: Grapefruit juice may interfere with the absorption of sildenafil, affecting how the medication works.

Is Viagra for women, too?

Concerns about sexual desire and performance are common among adults, and it's an issue often discussed with health care professionals such as Dr. Salena Zanotti. In an article by the Cleveland Clinic, she explains that while Viagra is well-known for treating erectile dysfunction in men, it's not approved by the U.S. Food and Drug Administration (FDA) for use in women.

However, there's a hypothesis that Viagra's effects, such as increased blood flow, might benefit women and individuals assigned female at birth (AFAB) by potentially improving vaginal lubrication, sensitivity and pleasure. As Zanotti points out, clinical studies haven't shown Viagra to be a solution for sexual dysfunction beyond its intended use.

For women facing sexual desire challenges, other medications like Addyi (flibanserin), Vyleesi (bremelanotide), Wellbutrin (bupropion), and hormone replacement therapy may be considered. These alternatives focus on increasing interest in sex and addressing sexual concerns specific to women.

Viagra for erectile dysfunction

Viagra is a well-known remedy for erectile dysfunction. According to the FDA, Viagra significantly improved erections in 48%-57% of patients, compared to 10%-12% with a placebo. This shows the therapeutic potential of Viagra and its role in enhancing the quality of life for those facing specific impotence.

Resources

Cleveland Clinic: Erectile Dysfunction

U.S. National Library of Medicine (MedlinePlus): Sildenafil

Mayo Clinic: Sildenafil (Oral Route)

Frontiers in Pharmacology: The Effect of Phosphodiesterase-type 5 Inhibitors on Erectile Function: An Overview of Systematic Reviews

Urologic Surgeons of Washington: Comparing Tadalafil (Generic Cialis) and Sildenafil (Generic Viagra)

NHS of England: Side Effects of Sildenafil

U.S. Food and Drug Administration (FDA): Viagra