How To Take This Medication:
This drug is taken by mouth as needed between four hours and one-half hour before sexual activity (about one hour before is most effective). Take only as directed, usually once daily as needed.
Sildenafil works along with sexual stimulation to help achieve an erection.

Side Effects:
Headache, flushing, stomach upset, nasal stuffiness, diarrhea and dizziness might occur. If these effects persist or worsen, notify your doctor promptly.
Unlikely but report promptly: painful or other urination problems, vision problems, skin rash.
Very unlikely but report promptly: chest pain, fainting, foot or ankle swelling.
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.

Precautions:
Before using this drug, tell your doctor 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 disease, bleeding disorders, active stomach ulcers, heart disease, stroke, very high or low blood pressure.
Limit alcohol intake, as it may aggravate side effects of this drug.
Since this drug 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 in women or children.
The elderly may be more sensitive to the side effects of this drug, therefore caution is advised in this group.

Drug Interactions:
Do not take Viagra, Cialis or Levitra within 24 hours of each other. Tell your doctor of all nonprescription and prescription medication you may use, especially any 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) or high blood pressure medicines.

Overdose:
If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include severe dizziness, fainting, or prolonged erection.

Notes:
Do not take Viagra, Cialis or Levitra within 24 hours of each other. 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.