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Sildenafil
More commonly known as Viagra
VIAGRA (Sildenafil) PRECAUTIONS:
Before using VIAGRA, inform your doctor of your complete 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 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. VIAGRA 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:
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). Do not start or stop any medicine without doctor or
pharmacist approval.....
Why is this medication prescribed?
Sildenafil is used to treat erectile
dysfunction (impotence; inability to get or keep an erection) in men.
Sildenafil is in a class of medications called phosphodiesterase (PDE)
inhibitors. It works by increasing blood flow to the penis during
sexual stimulation. This increased blood flow can cause an erection.
Sildenafil does not cure erectile dysfunction or increase sexual
desire. Sildenafil does not prevent pregnancy or the spread of sexually
transmitted diseases such as human immunodeficiency virus (HIV).
How should this medicine be used?
Sildenafil comes as a tablet to take by mouth.
It should be taken as needed about 1 hour before sexual activity.
However, sildenafil can be taken anytime from 4 hours to 30 minutes
before sexual activity. Sildenafil usually should not be taken more
than once every 24 hours. If you have certain health conditions or are
taking certain medications, your doctor may tell you to take sildenafil
less often. Follow the directions on your prescription label carefully,
and ask your doctor or pharmacist to explain any part you do not
understand. Take sildenafil exactly as directed. Do not take more or
less of it or take it more often than prescribed by your doctor.
You
can take sildenafil with or without food. However, if you take
sildenafil with a high-fat meal, it will take longer for the medication
to start to work.
Your doctor will probably
start you on an average dose of sildenafil and increase or decrease
your dose depending on your response to the medication. Tell your
doctor if sildenafil is not working well or if you are experiencing
side effects.
Other uses for this medicine
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking sildenafil,
- tell your doctor and pharmacist if you are allergic to sildenafil or any other medications.
- do not take sildenafil if you are taking taking or have recently
taken nitrates such as isosorbide dinitrate (Isordil), isosorbide
mononitrate (Imdur, ISMO), and nitroglycerin (Nitro-BID, Nitro-Dur,
Nitroquick, Nitrostat, others). Nitrates come as tablets, sublingual
(under the tongue) tablets, sprays, patches, pastes, and ointments. Ask
your doctor if you are not sure whether any of your medications contain
nitrates.
- do not take street drugs containing nitrates such as amyl nitrate and butyl nitrate ('poppers') while taking sildenafil.
- tell your doctor and pharmacist what prescription and
nonprescription medications, vitamins, and nutritional supplements you
are taking or plan to take, especially alpha blockers such as alfuzosin
(Uroxatral), doxazosin (Cardura), prazosin (Minipress), tamsulosin
(Flomax), and terazosin (Hytrin); amiodarone (Cordarone, Pacerone);
amlodipine (Norvasc) ; certain antifungals such as fluconazole
(Diflucan), griseofulvin (Fulvicin, Grifulvin, Gris-PEG), itraconazole
(Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend);aprepitant
(Emend); carbamazepine (Carbatrol, Epitol, Tegretol);cimetidine
(Tagamet, Tagamet HB); clarithromycin (Biaxin, in Prevpac);
cyclosporine (Neoral, Sandimmune);delaviridine
(Rescriptor);dexamethasone (Decadron, Dexpak); diltiazem (Cardizem,
Dilacor, Tiazac, others); efavirenz (Sustiva); erythromycin (E.E.S.,
E-Mycin, Erythrocin); fluoxetine (Prozac, Sarafem); fluvoxamine
(Luvox); HIV protease inhibitors including atazanavir (Reyataz),
indinavir (Crixivan), lopinavir (in Kaletra),nelfinavir (Viracept),
ritonavir (Norvir, in Kaletra), and saquinavir (Fortovase, Invirase);
lovastatin (Advicor, Altocor, Mevacor); nefazodone; nevirapine
(Viramune);other medications or devices to treat erectile dysfunction;
phenobarbital; phenytoin (Dilantin, Phenytek); rifabutin
(Mycobutin);rifampin (Rifadin, Rimactane); sertraline (Zoloft);
troleandomycin (TAO); verapamil (Calan, Covera, Isoptin, Verelan);and
zafirlukast (Accolate).
- tell your doctor what herbal products you are taking or plan to take, especially St. John's wort..
- tell your doctor if you smoke and if you have ever had an erection
that lasted for several hours. Also tell your doctor if you have or
have ever had a bleeding disorder, a stomach ulcer; heart, kidney, or
liver disease; a heart attack; an irregular heartbeat; chest pain; a
stroke; high or low blood pressure; high cholesterol; blood cell
problems such as sickle cell anemia (a disease of the red blood cells),
multiple myeloma (cancer of the plasma cells), or leukemia (cancer of
the white blood cells); conditions affecting the shape of the penis
(e.g., angulation, cavernosal fibrosis, or Peyronie's disease); or
diabetes. Also tell your doctor if you or any of your family members
have or have ever had an eye disease such as retinitis pigmentosa or if
you have ever had severe vision loss, especially if you were told that
the vision loss was caused by a blockage of blood flow to the nerves
that help you see. Tell your doctor if you have ever been advised by a
health care professional to avoid sexual activity for medical reasons
or if you have ever experienced chest pain during sexual activity.
- you should know that sildenafil is only for use in males. Women
should not take sildenafil, especially if they are or could become
pregnant or are breast-feeding. If a pregnant woman takes sildenafil,
she should call her doctor.
- if you are having surgery, including dental surgery, tell your doctor or dentist that you take sildenafil.
- you should know that sexual activity may be a strain on your heart,
especially if you have heart disease. If you have chest pain during
sexual activity, call your doctor immediately and avoid sexual activity
until your doctor tells you otherwise.
- tell all your health care providers that you are taking sildenafil.
If you ever need emergency medical treatment for a heart problem, the
health care providers who treat you will need to know when you last
took sildenafil.
What special dietary instructions should I follow?
Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine.
What side effects can this medication cause?
Sildenafil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- headache
- upset stomach
- diarrhea
- dizziness or lightheadedness
- flushing (feeling of warmth)
- stuffy nose
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
- sudden severe loss of vision (see below for more information)
- blurred vision
- changes in color vision (seeing a blue tinge on objects or having difficulty telling the difference between blue and green)
- painful erection
- prolonged erection (longer than 4 hours)
- fainting
- chest pain
- itching or burning during urination
- rash
Some patients experienced a sudden loss of
some or all of their vision after they took sildenafil or other
medications that are similar to sildenafil. The vision loss was
permanent in some cases. It is not known if the vision loss was caused
by the medication. If you experience a sudden loss of vision while you
are taking sildenafil, call your doctor immediately. Do not take any
more doses of sildenafil or similar medications such as tadalafil
(Cialis) or vardenafil (Levitra) until you talk to your doctor.
Sildenafil may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.
If
you experience a serious side effect, you or your doctor may send a
report to the Food and Drug Administration's (FDA) MedWatch Adverse
Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].
What storage conditions are needed for this medicine?
Keep this medication in the container it came
in, tightly closed, and out of reach of children. Store it at room
temperature and away from excess heat and moisture (not in the
bathroom). Throw away any medication that is outdated or no longer
needed. Talk to your pharmacist about the proper disposal of your
medication.
In case of emergency/overdose
In case of overdose, call your local poison
control center at 1-800-222-1222. If the victim has collapsed or is not
breathing, call local emergency services at 911.
What other information should I know?
Keep all appointments with your doctor.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Brand names
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