|
Indications and Usage
Sildenafil relaxes muscles and
increases blood flow to particular areas of the body. Sildenafil is
used to treat erectile dysfunction (impotence) and for the treatment
of pulmonary arterial hypertension. Sildenafil may also be used for
purposes other than those listed in this medication guide.
Important Information
A small number of patients
have lost eyesight in one eye after taking sildenafil. This type of
vision loss is called non-arteritic anterior ischemic optic
neuropathy (NAION). NAION causes a sudden loss of eyesight because
blood flow is blocked to the optic nerve. It is not clear at this
time if sildenafil causes NAION. NAION also happens in patients who
do not take this medicine. People who have a higher chance for NAION
include those who:
· have heart disease;
· are over 50 years
old;
· have diabetes;
· have high blood pressure;
· have
high cholesterol;
· smoke; or
· have certain eye problems.
Stop using sildenafil if you have any loss in your eyesight and
seek medical help right away. Do not take sildenafil if you are
using a nitrate drug for chest pain or heart problems. Nitrates
include nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur,
Nitro-Bid, Minitran, Deponit, Transderm-Nitro, others), isosorbide
dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide
mononitrate (Imdur, ISMO, Monoket). Nitrates are also found in some
recreational drugs such as amyl nitrate or nitrite ("poppers").
Contact your doctor or seek emergency medical attention for any
erection that lasts longer than 4 hours. A sustained erection can
damage the penis. Refrain from further sexual activity and notify
your doctor it you develop dizziness, nausea, or angina (pain,
tightness, discomfort, numbness, or tingling in the chest, arms,
neck, or jaw) during sexual activity. Do not take sildenafil more
than once a day.
Contraindications
A small number
of patients have lost eyesight in one eye after taking sildenafil.
This type of vision loss is called non-arteritic anterior ischemic
optic neuropathy (NAION). NAION causes a sudden loss of eyesight
because blood flow is blocked to the optic nerve. It is not clear at
this time if sildenafil causes NAION. NAION also happens in patients
who do not take this medicine. People who have a higher chance for
NAION include those who:
· have heart disease;
· are over 50
years old;
· have diabetes;
· have high blood pressure;
· have high cholesterol;
· smoke; or
· have certain eye
problems.
Stop using sildenafil if you have any loss in your
eyesight and seek medical help right away. Do not take sildenafil if
you are using a nitrate drug for chest pain or heart problems.
Nitrates include nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur,
Nitro-Bid, Minitran, Deponit, Transderm-Nitro, others), isosorbide
dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide
mononitrate (Imdur, ISMO, Monoket). Nitrates are also found in some
recreational drugs such as amyl nitrate or nitrite ("poppers").
Before taking sildenafil, tell your doctor if you
· have had a
heart attack, stroke, or life-threatening irregular heartbeats
within the last six months;
· have a history of heart failure;
· have coronary artery disease;
· have angina;
· have
high or low blood pressure;
· have liver problems;
· have
kidney problems;
· have ever had blood problems, including
sickle cell anemia or leukemia;
· have a bleeding disorder;
· have a stomach ulcer;
· have retinitis pigmentosa (an
inherited condition of the eye);
· have a physical deformity of
the penis such as Peyronie's disease;
· have a condition that
could lead to prolonged and painful erections, such as a tumor of
the bone marrow, sickle cell anemia, or leukemia; or
· are
taking another medicine to treat impotence, such as alprostadil
(Caverject, Muse, Edex) or yohimbine (Yocon, Yodoxin, others).
You may not be able to take sildenafil, or you may require a
dosage adjustment or special monitoring during treatment if you have
any of the conditions listed above. Although sildenafil is not
indicated for use by women, it is in the FDA pregnancy category B.
This means that sildenafil is not expected to be harmful to an
unborn baby. Sildenafil should not be taken by women. It is not
known whether sildenafil passes into breast milk. Sildenafil should
not be taken by women. If you are over 65 years of age, you may be
more likely to experience side effects from sildenafil. Your doctor
may prescribe a lower dose of this medication.
Dosage and
Administration
Take sildenafil exactly as directed by your
doctor. If you do not understand these directions, ask your
pharmacist, nurse, or doctor to explain them to you. Take each dose
with a full glass of water. Sildenafil is usually taken when needed.
It can be taken anywhere from 4 hours to one-half hour before sexual
activity. Generally, it is taken 1 hour before sexual activity. The
medication can help achieve an erection when sexual stimulation
occurs. An erection will not occur just by taking a pill. Follow
your doctor's instructions. Taking sildenafil after eating a
high-fat meal (such as a cheeseburger and french fries) may cause
the medication to take a little longer to start working. Do not take
sildenafil more than once a day. If you develop dizziness, nausea,
or angina (pain, tightness, discomfort, numbness, or tingling in the
chest, arms, neck, or jaw) during sexual activity, refrain from
further sexual activity and notify your doctor. Contact your doctor
or seek emergency medical attention for any erection that lasts
longer than 4 hours. A sustained erection can damage the penis.
Grapefruit and grapefruit juice may interact with sildenafil. The
interaction could lead to potentially adverse effects. You should
discuss the use of grapefruit and grapefruit juice with your doctor.
Do not increase or decrease the amount of grapefruit products in
your diet without first talking to your doctor.
Possible
Side Effects
If you experience any of the following serious
side effects, stop taking sildenafil and seek emergency medical
attention or notify your doctor immediately:
· an allergic
reaction (difficulty breathing; closing of the throat; swelling of
the lips, tongue, or face; or hives);
· chest pain or an
irregular heartbeat;
· swelling of the ankles or legs;
·
shortness of breath;
· prolonged or severe dizziness;
· a
prolonged (lasting longer than 4 hours) or painful erection; or
· dizziness, nausea, or angina (pain, tightness, discomfort,
numbness, or tingling in the chest, arms, neck, or jaw).
Other,
less serious side effects may be more likely to occur. Continue to
take sildenafil and talk to your doctor if you experience
·
flushing;
· mild dizziness;
· headache;
· nasal
congestion;
· diarrhea;
· temporary blue tint in vision or
other vision abnormalities; or
· itching or a rash.
Side
effects other than those listed here may also occur. Talk to your
doctor about any side effect that seems unusual or that is
especially bothersome.
Miss a Dose
Sildenafil is
used as needed, so you are not likely to miss a dose.
Overdosage
Seek emergency medical attention.
Symptoms of a sildenafil overdose are not known, but are likely to
include chest pain, dizziness, an irregular heartbeat, and swelling
of the ankles or legs.
Drug Interaction
Do not
take sildenafil if you are using a nitrate drug for chest pain or
heart problems. Nitrates include nitroglycerin (Nitrostat,
Nitrolingual, Nitro-Dur, Nitro-Bid, Minitran, Deponit,
Transderm-Nitro, others), isosorbide dinitrate (Dilatrate-SR,
Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO,
Monoket). Nitrates are also found in some recreational drugs such as
amyl nitrate or nitrite ("poppers"). Before taking sildenafil, tell
your doctor if you are taking any of the following medications:
· any other drug used to treat impotence, such as alprostadil
(Caverject, Muse, Edex) or yohimbine (Yocon, Yodoxin, others);
·
the antibiotic drugs clarithromycin (Biaxin), erythromycin (E-Mycin,
Eryc, Ery-Tab, others), or troleandomycin (TAO);
· an antifungal
medication such as itraconazole (Sporanox) or ketoconazole
(Nizoral);
· the HIV medications amprenavir (Agenerase),
delavirdine (Rescriptor), indinavir (Crixivan), nelfinavir
(Viracept), ritonavir (Norvir), or saquinavir (Fortovase, Invirase);
· cimetidine (Tagamet, Tagamet HB);
· phenobarbital
(Luminal);
· carbamazepine (Tegretol) or phenytoin (Dilantin);
or
· rifampin (Rifadin, Rifamate) or rifabutin (Mycobutin).
You may not be able to take sildenafil, or you may require a
dosage adjustment or special monitoring during treatment if you are
taking any of the medicines listed above. Drugs other than those
listed here may also interact with sildenafil or affect your
condition. Talk to your doctor or pharmacist before taking any
prescription or over-the-counter medicines, including herbal
products.
Precautions
Do not take any other drug
used to treat impotence, such as alprostadil (Caverject, Muse, Edex)
or yohimbine (Yocon, Yodoxin, others), without first talking to your
doctor. Grapefruit and grapefruit juice may interact with
sildenafil. The interaction could lead to potentially adverse
effects. You should discuss the use of grapefruit and grapefruit
juice with your doctor. Do not increase or decrease the amount of
grapefruit products in your diet without first talking to your
doctor.
Storage
Store this medication at room
temperature away from moisture and heat.
|
