Sildenafil Citrate

Sildenafil Citrate. Drug and Patient Information. Dosage. Overdose. Generic or Brand Sildenafil Citrate. For Professionals and Consumers.

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Sildenafil Citrate is an oral drug for male impotence, also known as erectile dysfunction (ED). It works by dilating blood vessels in the penis, allowing the inflow of blood needed for an erection.

Brand name: Viagra

Generic Name: Sildenafil Citrate


Most important fact about Sildenafil Citrate

Sildenafil Citrate causes erections only during sexual excitement. It does not work in the absence of arousal.

How should you take Sildenafil Citrate?

Taking Sildenafil Citrate approximately 1 hour before sexual activity works best for most men. Depending on how and when the drug works for you, an interval of one-half hour to as much as 4 hours may prove ideal.

If you miss a dose of Sildenafil Citrate

Sildenafil Citrate is not for regular use. Take it only before sexual activity.

Storage instructions for Sildenafil Citrate

Store at room temperature.

What side effects may occur when taking Sildenafil Citrate?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Sildenafil Citrate.

More common side effects of Sildenafil Citrate may include:

Abnormal vision (color tinge, blurring, sensitivity to light), acid indigestion, diarrhea, flushing, headache, nasal congestion, urinary tract infection

Heart attack, stroke, heart irregularities, dangerous surges in blood pressure, and sudden death have all been reported after use of Sildenafil Citrate, usually in men with existing cardiac risk factors, and typically during or shortly after sex.

Why should Sildenafil Citrate not be prescribed?

Do not take Sildenafil Citrate if you are taking any nitrate-based drug, including nitroglycerin patches (Nitro-Dur, Transderm-Nitro), nitroglycerin ointment (Nitro-Bid, Nitrol), nitroglycerin pills (Nitro-Bid, Nitrostat), and isosorbide pills (Dilatrate-SR, Isordil, Sorbitrate). Combining Sildenafil Citrate with these drugs can cause a severe drop in blood pressure.

If Sildenafil Citrate gives you an allergic reaction, do not use it again.

Special warnings about Sildenafil Citrate

If you have heart problems severe enough to make sexual activity a danger, you should avoid using Sildenafil Citrate. Use it cautiously–if at all–if you’ve had a heart attack, stroke, or life-threatening heart irregularities within the past 6 months. Be equally cautious if you have severe high or low blood pressure, heart failure, or unstable angina (crushing heart pain that occurs at any time).

If you take Sildenafil Citrate and develop cardiac symptoms (for example, dizziness, nausea, and chest pain) during sexual activity, do not continue. Alert your doctor to the problem as soon as possible.

If you have a condition that might result in long-lasting erections, such as sickle cell anemia, multiple myeloma (a disease of the bone marrow), or leukemia, use Sildenafil Citrate with caution. Also use cautiously if you have a genital problem or deformity such as Peyronie’s disease. If an erection lasts more than 4 hours, seek treatment immediately. Permanent damage and impotence could result.

If you have a bleeding disorder, a stomach ulcer, or the inherited eye condition known as retinitis pigmentosa, use this medication with caution. Its safety under these circumstances has not yet been studied.

To avoid low blood pressure, do not take the 50-milligram or 100-milligram dose of Sildenafil Citrate within 4 hours of taking an alpha-blocking drug such as Cardura.

Remember that Sildenafil Citrate offers no protection from transmission of sexually transmitted diseases, such as HIV, the virus that causes AIDS.

Possible food and drug interactions when taking Sildenafil Citrate

If Sildenafil Citrate is taken with certain other drugs, the effects of either could be increased, decreased, or altered.

It is especially important to check with your doctor before combining Sildenafil Citrate with the following:

Other impotence remedies including Caverject and Muse
Alpha-blockers such as doxazosin (Cardura)
Amlodipine (Norvasc)
Cimetidine (Tagamet)
Erythromycin (E-Mycin, Ery-Tab, PCE)
Itraconazole (Sporanox)
Ketoconazole (Nizoral)
Nitrates such as Isordil, Nitro-Bid, and Nitro-Dur
Rifampin (Rifadin, Rimactane)
Ritonavir (Norvir)
Saquinavir (Fortovase, Invirase)

Special information on Sildenafil Citrate if you are pregnant or breastfeeding

Sildenafil Citrate should not be used by women. Its affects during pregnancy and breastfeeding have not been studied.

Recommended dosage of Sildenafil Citrate

Doses range from 25 milligrams to 100 milligrams, depending on the drug’s effect. The usual dose is 50 milligrams. If you are over 65, have liver or kidney problems, or are taking erythromycin, ketoconazole, itraconazole, ritonavir, or saquinavir a dose of 25 milligrams may be sufficient. Your doctor will adjust the dosage if the drug is not working properly for you.

Take Sildenafil Citrate only before sexual activity. The manufacturer recommends a maximum of 1 dose per day (1 dose every 2 days for those taking ritonavir).

To avoid low blood pressure, do not take the 50-milligram or 100-milligram dose of Sildenafil Citrate within 4 hours of taking an alpha-blocking drug such as Cardura.

Overdosage when taking Sildenafil Citrate

No overdose of Sildenafil Citrate has been reported. However, any medication taken in excess can have serious consequences. If you suspect an overdose with Sildenafil Citrate, seek medical attention immediately.

Other uses of Sildenafil Citrate

Pulmonary hypertension

As well as erectile dysfunction, Sildenafil Citrate is also effective in the rare disease pulmonary arterial hypertension (PAH). It relaxes the arterial wall, leading to decreased pulmonary arterial resistance and pressure. This in turn reduces the workload of the right ventricle of the heart and improves symptoms of right-sided heart failure.

Because PDE-5 is primarily distributed within the arterial wall smooth muscle of the lungs and penis, Sildenafil Citrate acts selectively in both these areas without inducing vasodilation in other areas of the body. Pfizer submitted an additional registration for Sildenafil Citrate to the FDA, and Sildenafil Citrate was approved for this indication in June 2005. The preparation is named Revatio, to avoid confusion with Sildenafil Citrate, and the 20 milligram pills are white and round. Sildenafil Citrate joins bosentan and prostacyclin-based therapies for this condition.

Raynaud’s phenomenon

In 2005, Dr. Roland Fries and colleagues reported that Sildenafil Citrate cut the frequency of Raynaud’s phenomenon attacks, reduced their duration by roughly one half, and more than quadrupled the mean capillary blood velocity. This was a double-blind, placebo-controlled crossover trial and the patients had both the primary and secondary forms and had all discontinued the more conventional treatments for this.

Sildenafil Citrate and altitude sickness

Sildenafil Citrate has been shown to be useful for the prevention and treatment of High altitude pulmonary edema associated with altitude sickness such as that suffered by mountain climbers. While this effect has only recently been discovered, Sildenafil Citrate is already becoming an accepted treatment for this condition, particularly in situations where the standard treatment of rapid descent has been delayed for some reason.

Duchenne/Becker Muscular Dystrophy

Sildenafil Citrate has recently been used to enhance cGMP signaling, specifically downstream and independent of NO formation, in dystrophin-deficient mouse hearts. Chronic treatment improved contractile performance, myocardial metabolic status, and sarcolemmal integrity, highlighting its potential clinical avenue for the treatment of the dystrophin-related cardiomyopathies.

Sildenafil Citrate and the use in sports

Professional sports players have been using drugs such as Sildenafil Citrate thinking that the opening of their blood vessels will enrich their muscles, therefore enhancing their performance.

Non-medical use of Sildenafil Citrate


Sildenafil Citrate is commonly and increasingly used as an aphrodisiac, i.e. to increase sexual desire. However, there is no clinical evidence that Sildenafil Citrate has aphrodisiac activity, because it does not have any direct effect on the brain, although increased ability to attain an erection may be interpreted as increased sexual arousal by users of these drugs.