Posted on February 27th, 2013 by

Class: Other

Generic Name: Sildenafil

Trade Names: Viagra®

How is this drug used? Viagra is used to treat erectile dysfunction in men. Erectile dysfunction (ED) involves difficulty getting or keeping an erection.

What is the mechanism of action? When a man is sexually excited, Viagra can help the penis fill with enough blood to cause an erection. Viagra treats—but does not cure—erectile dysfunction. A man must be sexually excited in order to benefit from Viagra; the pill alone does not cause an erection.

How is Viagra given (administered)? Viagra is taken orally (by mouth) about one hour prior to sex.

How are patients monitored? Patients will need to evaluated by their physician before starting treatment with Viagra. A thorough medical examination is necessary in order to diagnose erectile dysfunction. An examination is also necessary in order to determine whether a man is healthy enough for sexual activity and whether he can safely take Viagra. Sexual activity may not be advisable for men with heart problems.

What are the most common side effects of treatment with Viagra?

  • Headache
  • Flushing of the face
  • Upset stomach 

Less common side effects include temporary changes in color vision, eye sensitivity to light, or blurred vision.

What are some of the potentially serious side effects of treatment with Viagra?

  • Sudden decrease or loss of vision in one or both eyes
  • An erection that lasts many hours (get immediate medical help if an erection lasts longer than four hours)
  • Sudden loss or decrease in hearing
  • Heart attack, stroke, irregular heart beats, or death

This is not a complete list of side effects. Some patients may experience other side effects that are not listed here. Patients may wish to discuss with their physician the other less common side effects of this drug, some of which may be serious.

Some side effects may require medical attention. Other side effects do not require medical attention and may go away during treatment. Patients should check with their physician about any side effects that continue or are bothersome.

What can patients do to help alleviate or prevent discomfort and side effects?

  • Pay careful attention to the physician’s instructions, and discuss side effects with your physician.
  • Do not take Viagra if you take any drugs that contain nitrates. The combination of Viagra and nitrates can cause a life-threatening drop in blood pressure. Nitrates are present in some prescription drugs as well as recreational drugs known as “poppers.”

Are there any special precautions patients should be aware of before starting treatment?

  • Patients should inform their physician about all medical conditions, including current or past heart problems, stroke, high or low blood pressure, severe vision loss, retinitis pigmentosa, kidney problems, liver problems, blood problems, allergies, a deformed penis, Peyronie’s disease, an erection that lasted more than four hours, stomach ulcers, or bleeding problems.
  • Patients should inform their physician of any other medication or supplement they are taking (whether prescription or over-the-counter), including medicines that contain nitrates, alpha-blockers, and protease inhibitors.
  • Viagra does not protect against sexually transmitted diseases.
  • Viagra should not be used with other medical treatments for erectile dysfunction.
  • Viagra contains the same active ingredient as another drug called Revatio. Revatio is used for the treatment of pulmonary arterial hypertension. Viagra should not be used with Revatio.

When should patients notify their physician?

Tell your doctor if you experience any side effects that bother you or don’t go away. Also seek immediate medical care if have an erection that lasts for longer than four hours (an erection that lasts for too long can permanently damage the penis); if you have chest pain, dizziness, or nausea during sex; or if you experience a sudden loss or decrease of vision or hearing.

What is a package insert?

A package insert is required by the FDA and contains a summary of the essential scientific information needed for the safe and effective use of the drug for healthcare providers and consumers.  A package insert typically includes information regarding specific indications, administration schedules, dosing, side effects, contraindications, results from some clinical trials, chemical structure, pharmacokinetics and metabolism of the specific drug. By carefully reviewing the package insert, you will get the most complete and current information about how to safely use this drug. If you do not have the package insert for the drug you are using, your pharmacist or physician may be able to provide you with a copy.

Copyright © 2016 CancerConnect Last updated 02/13.

Important Limitations of Use

The information provided above on the drug you have selected is provided for your information only and is not a substitute for consultation with an appropriate medical doctor.  We are providing this information solely as a courtesy and, as such, it is in no way a recommendation as to the safety, efficacy or appropriateness of any particular drug, regimen, dosing schedule for any particular cancer, condition or patient nor is it in any way to be considered medical advice. Patients should discuss the appropriateness of a particular drug or chemotherapy regimen with their physician.

As with any printed reference, the use of particular drugs, regimens and drug dosages may become out-of-date over time, since new information may have been published and become generally accepted after the latest update to this printed information.  Please keep in mind that health care professionals are fully responsible for practicing within current standards, avoiding use of outdated regimens, employing good clinical judgment in selecting drugs and/or regimens, in calculating doses for individual patients, and verifying all dosage calculations.



The prescribing physician is solely responsible for making all decisions relating to appropriate patient care including, but not limited to, drugs, regimens, dose, schedule, and any supportive care.

Tags: Drug Dictionary, Miscellaneous, Other, S

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