How to use
Viagra^® is taken orally as needed anywhere from 30 minutes to 4 hours before sexual activity (taking the medication about one hour before is most effective). Take only as directed, usually once daily as needed. Viagra^® works along with sexual stimulation to help achieve an erection.

Overdose
If you suspect an overdose of Viagra^®, contact your local poison control center or emergency room immediately. Symptoms of an overdose may include severe dizziness, fainting, or prolonged erection.

Missed dose
Viagra^® is taken when needed, so you are unlikely to miss a dose.

Notes
Do not share this medication with others, since they may have a problem that is not effectively treated by this drug. Use of this drug does not protect against sexually transmitted diseases (e.g., HIV, Hepatitis B, gonorrhea, syphilis)

Storage
Store at room temperature between 59 and 86 degrees F (15-30 degrees C) away from light and moisture. KEEP THIS AND ALL MEDICATIONS OUT OF REACH OF CHILDREN.

 
Important note
The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed that the taking of this medication is safe, appropriate or effective for you.

Precautions
Before using Viagra^®, inform your doctor of your medical history, including:

• Allergies (especially drug allergies)
• Penis conditions such as fibrosis/scarring (e.g., Peyronie's disease)
• History of painful/prolonged erection (priapism)
• Sickle cell anemia
• Blood system cancers (such as leukemia or myeloma)
• Eye problems (retina diseases)
• Kidney or liver diseases
• Bleeding disorders
• Active stomach ulcers
• Heart diseases
• Strokes
• Very high or low blood pressure

Limit alcohol intake, as it may aggravate side effects of this drug. Since Viagra^® may cause dizziness, caution is advised when performing tasks requiring alertness (e.g., driving). To avoid dizziness and lightheadedness when rising from a seated or lying position, get up slowly. This drug is not to be used by women or children. The elderly may be more sensitive to the side effects of Viagra^®, therefore caution is advised for this group.

Drug interactions
Inform your doctor of all nonprescription and prescription medication you may use, especially of:

• Nitrate medications (e.g., nitroglycerin, isosorbide dinitrate), nitroprusside (any " nitric oxide donor" medicines), cimetidine, erythromycin, azole antifungals (e.g., itraconazole, ketoconazole), mibefradil, rifamycins (e.g., rifampin)
• High blood pressure medicines
• Certain HIV protease inhibitors (such as saquinavir, ritonavir, amprenavir), delavirdine

Do not start or stop any medicine without doctor or pharmacist approval.

When using Viagra^®, the following side effects may occur:

• Headache
• Flushing
• Upset stomach
• Nasal stuffiness
• Diarrhea
• Dizziness

If these effects persist or worsen, notify your doctor immediately.

Should the following unlikely side effects occur, report them immediately:

• Painful or other urination problems
• Vision problems
• Skin rash
• Chest pain
• Fainting
• Swelling of the ankle or foot

If you experience a painful or prolonged erection (lasting longer than 4 hours), stop using this drug and seek immediate medical attention. If you notice other effects not listed above, contact your doctor or pharmacist.