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FOSAMPRENAVIR
Other NAMES: Telzir®
WHY is this drug prescribed?
Fosamprenavir is an antiretroviral (anti-HIV) drug that belongs
to a class of drugs called protease inhibitors. Protease
inhibitors
interfere with a different step in virus reproduction than other
classes of drugs previously available to fight HIV. Fosamprenavir
is used together with other antiretrovirals (usually in combination
with ritonavir) to delay the progression of HIV infection. By
doing this, your immune system should improve (increase in
CD4+ count)
and you will be better protected against infections.
Fosamprenavir does not cure AIDS or completely kill the HIV virus,
but helps to prevent further damage by slowing down the production
of new viruses. Treatment with fosamprenavir does not reduce the
risk of passing infection on to others. You will still be able to
pass HIV by sexual contact, by blood transfer or by sharing needles.
You should always use appropriate precautions to prevent passing
HIV on to others.
HOW should this drug be taken?
Fosamprenavir is available as a 700 mg film-coated tablet, so it
is more easily swallowed and an oral suspension containing 50
mg/mL of active drug. The dose of fosamprenavir 1400mg (2 x 700
mg tablets)
in combination with ritonavir 200 mg (2 x 100 mg) may be taken
once daily or divided into two doses every 12 hours. This dose
may need to be adjusted if you are taking other protease inhibitors
or to meet your particular needs.
Fosamprenavir is also available as an oral 50 mg/mL suspension
for patients who cannot swallow the tablets. The liquid is off-white
with a grape bubblegum and peppermint flavour. Shake the bottle
well
before taking your dose. This suspension should be taken without
food on an empty stomach.
Fosamprenavir tablets can be taken with or without food.
Your dosage is:
____tablets (____mg) ____ times a day +
____ ritonavir (___mg) ___times a day,
OR
50 mg / mL oral suspension
____mL (____mg) ____ times a day +
____ ritonavir (____mg) ____times a day
Swallow tablets whole with some water or non-alcoholic drink.
Avoid drinking excessive amounts of alcohol while you are taking
fosamprenavir tablets. If you are taking fosamprenavir suspension,
it is best to completely
avoid alcoholic beverages.
What should you do if you FORGET a dose?
If you miss a dose of fosamprenavir, take it as soon as possible.
However, if it is time for your next dose, do not double the
dose, just carry on with your regular schedule.
Why should you not forget to take this drug?
If you miss doses of fosamprenavir, the amount of HIV virus in your
blood (known as the viral load) will start increasing again and
your immune system will be further damaged. A few missed doses
can be enough for fosamprenavir to stop being active. When this
happens, it is known as resistance. Other antiretrovirals that
work in a similar way as fosamprenavir may also become inactive.
Therefore, missing doses of fosamprenavir can cut down treatment
choices for the future.
Please do not stop fosamprenavir without talking to your doctor first.
What ADVERSE EFFECTS can this drug cause? What should you do about
them?
The
most common side effects people report with fosamprenavir include
stomach upset, gas, abdominal pain, diarrhea and vomiting If you
get a headache, this can usually be controlled with non-prescription
drugs, such as acetaminophen (Tylenol®).
Other side effects that may occur are tiredness and an increase
in cholesterol in the blood. People have complained about skin
rashes,
but in most cases this effect goes away on its own, without having
to stop treatment. Severe rashes have rarely been reported. Tell
your doctor if you have an allergy to sulphonamides. If these effects
occur and are bothersome, please call the clinic or discuss them
at your next visit.
Regular blood tests will be done to detect any changes in your
liver or pancreas function. Also, your doctor will look for increases
in
your cholesterol, triglyceride and blood sugar level.
The long-term effects of fosamprenavir are unknown at this time.
Further studies are being carried out. Abnormal weight gain or changes
in body shape have been reported, but it is uncertain if fosamprenavir
is responsible for these changes.
It is important that you keep your doctor appointments and come for
your laboratory tests so that your progress can be followed.
What other PRECAUTIONS should you follow while using this drug?
You must make sure that you are taking the right dose. If you take
higher doses of fosamprenavir than what is prescribed, you may
increase the chance of having adverse effects. If you take lower
doses of fosamprenavir than what is prescribed, the HIV virus
may become resistant to amprenavir.
Certain drugs can increase or decrease the effect of fosamprenavir.
Also, fosamprenavir might influence the effect of other drugs you
are taking. Inform your doctor and pharmacist of all prescribed,
non-prescribed drugs, herbals and nutritional supplements you are
taking. As well, you should inform them of natural products you are
taking. If you wish to start a new drug or natural product, please
consult with your pharmacist before doing so.
• Do
NOT take the following medications with fosamprenavir:
• Astemizole (Hismanal®)
• Cisapride (Prepulsid®)
• Diazepam
• Ergot derivatives [Ergotamine (Cafergot®, Bellergal®, Ergodryl®,
Gravergol®), ergonovine, dihydroergotamine (Migranal®), methylergonovine
(Methergine)]
• Flecainide (Tambacor®)
• Flurazepam
• Midazolam (Versed®)
• Pimozide (Orap®)
• Propafenone (Rhythmol®)
• Rifampin (e.g. Rifadin?, Rimactane®, Rofact®)
•
St. John’s Wort
• Triazolam (Halcion®)
• Terfenadine (Seldane®)
The efficacy of birth control pills or other hormones used to prevent
becoming pregnant may be decreased if you are taking fosamprenavir.
A second method of contraception should always be used. In general,
even if you are not taking fosamprenavir, the use of condoms is always
recommended to decrease the risk of passing HIV on to others.
The safety of fosamprenavir tablets has not been established during
pregnancy. Please inform your doctor if you are pregnant. Your doctor
can recommend the right treatment to help reduce the risk of passing
the HIV virus on to your baby. Breastfeeding is NOT recommended if
you have HIV as you can transmit the virus to your baby through your
breast milk.
How should this drug be STORED?
Fosamprenavir tablets should be stored between 15 – 30C and
the oral suspension between 2 – 30C. Keep the tablets in
a dry place, protected from light. Do not allow the suspension
to freeze.
Keep medication well out of the reach of children. Ensure that
the drug has not expired by checking the expiry date (“EXP”)
shown on the outside of the package. The suspension has a shelf
life of 28 days from the time it is dispensed (the pharmacist will
put
that date on the side of the bottle).
Do not store in your bathroom, as heat and moisture may cause the
drug to be less active.
If you have any questions or concerns about this drug or if you are
experiencing adverse effects, please discuss them with your pharmacist,
doctor or nurse. Write questions or concerns down to ensure they
are addressed.
If you have any questions or concerns about this drug or if you
are experiencing adverse effects, please discuss them with your pharmacist,
doctor or nurse. Write questions or concerns down to ensure they
are addressed.
The following pharmacist is available to answer questions:
Pharmacist: __________________
Telephone: __________________
Reference: Product monograph Telzir® (fosamprenavir). Saint-Laurent,
Qc, Canada: GlaxoSmithKline, 2004.
Prepared
by the Ontario HIV Pharmacy Professional Specialty Group, 2005.
Additional
medication fact sheets and updates may be found at: www.tthhivclinic.com
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