Before taking Viagra, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell yourdoctor or pharmacist your medical history, especially of: heart problems(such as heart attack orlife-threatening irregular heartbeat in the past 6 months, chest pain/angina, heart failure), stroke in the past 6months, kidney disease, liverdisease,high or low bloodpressure, a severe loss of body water (dehydration), penis conditions(such as angulation, fibrosis/scarring, Peyronie\\\'s disease),history of painful/prolonged erection (priapism),conditions that may increase the risk of priapism (suchas sickle cellanemia, leukemia, multiple myeloma), eye problems (suchas retinitispigmentosa, sudden decreased vision, NAION).

This drug may make you dizzy or cause vision problems.Alcohol or marijuana can make you dizzier. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages.Talk to your doctor if you are using marijuana.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This brand of the drug is usually not used in women. During pregnancy, sildenafil should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk.Consult your doctor before breastfeeding.

Dosage Information

For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity.However, VIAGRA may be taken anywhere from 30 minutes to 4 hours before sexual activity. The maximum recommended dosing frequency is once per day.

Based on effectiveness and toleration, the dose may be increased to a maximum recommended dose of 100 mg decreased to 25 mg.

Use With Food

VIAGRA may be taken with or without food.

Dosage Adjustments In Specific Situations

VIAGRA was shown to potentiate the hypotensive effects of nitrates and its administration in patients who use nitric oxide donors such as organic nitrates or organic nitrites in any form is therefore contraindicated

Dosage Adjustments Due To Drug Interactions

The recommended dose for ritonavir-treated patients is 25 mg prior to sexual activity and the recommended maximum dose is25 mg within a 48 hour period because concomitant administration increased the blood levels of sildenafil by 11-fold.

Consider a starting dose of 25 mg in patients treated with strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, or saquinavir) or erythromycin.Clinical data have shown that co-administration with saquinavir or erythromycin increased plasma levels of sildenafil by about 3 fold.

What are the possible side effects of oral sildenafil (Revatio, Viagra)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

During sexual activity, if you become dizzy or nauseated, or have pain, numbness, or tingling in your chest, arms, neck, or jaw, stop and call your doctor right away. You could be having a serious side effect of sildenafil.

Stop using sildenafil and call your doctor at once if you have a serious side effect such as:

• sudden vision loss;
• ringing in your ears, or sudden hearing...
• Cardiovascular 
• Prolonged Erection and Priapism 
• Effects on the Eye
• Hearing Loss
• Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives
• Adverse Reactions with the Concomitant Use of Ritonavir
• Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies
• Effects on Bleeding
• Counseling Patients About Sexually Transmitted Diseases

The most common adverse reactions reported in clinical trials ( > 2%) are a headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.

VIAGRA was administered to over 3700patients (aged 19-87 years) during pre-marketing clinical trials worldwide.Over 550 patients were treated for longer than one year.

In placebo-controlled clinical studies, the discontinuation rate due to adverse reactions to VIAGRA (2.5%)was not significantly different from placebo (2.3%).

In fixed-dose studies, the incidence of some adverse reactions increased with dose. The type of adverse reactions in flexible-dose studies, which reflect the recommended dosage regimen, was similar to that for fixed-dose studies.

The following events occurred in< 2% of patients in controlled clinical trials; a causal relationship toVIAGRA is uncertain. Reported events include those with a plausible relation to drug use; omitted are minor events and reports too imprecise to be meaningful:

Body as a Whole: face edema, photosensitivity reaction, shock, asthenia, pain, chills, accidental fall, abdominal pain, allergic reaction, chest pain, accidental injury.

Cardiovascular: angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, cardiomyopathy.

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions.Information at the site cannot be used for self-treatment and self-diagnosis.Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.