What
is Aptivus
Aptivus is an anti-HIV
medication. It is in a category of HIV medicines
called protease
inhibitors (PIs). Aptivus prevents cells
infected by HIV from producing new virus. This
reduces the amount of virus in your body.
Aptivus must be used in
combination with Norvir
(ritonavir) and at least two other anti-HIV
drugs.
Aptivus, manufactured by
Boehringer Ingelheim, was approved for the treatment
of HIV by the U.S. Food and Drug Administration
(FDA) in June 2005. Aptivus/ritonavir is only
approved for HIV-infected people who have tried
and failed other anti-HIV drug regimens (including
those containing protease inhibitors) in the
past. It is not approved for HIV-infected people
starting anti-HIV treatment, or a protease inhibitor,
for the first time (unless they were infected
with a strain of HIV resistant to multiple protease
inhibitors).
What
is known about Aptivus
Aptivus has a different structure than other
protease inhibitors and is active against strains
of the virus that are resistant to the other
protease inhibitors that are currently available.
The correct
dose of Aptivus is 500mg twice a day (two 250mg
capsules twice daily) . To help keep levels
of Aptivus high in the blood, which is very
important for the drug to be effective, it is
necessary to combine Aptivus with low doses
(200mg twice daily) of the protease inhibitor
Norvir (ritonavir).
Aptivus/ritonavir
should be taken with food, preferably a complete
nutritious meal, to ensure proper absorption
of the drug into the bloodstream.
Aptivus
is recommended by the U.S. Department of Health
and Human Services (DHHS) for HIV-positive people
who have tried and failed other protease inhibitors
in the past. It is not recommended by the DHHS
for patients who are new to anti-HIV treatment
or starting a protease inhibitor for the first
time.
Clinical
trials have demonstrated that Aptivus is an
effective option for patients who are not likely
to respond to older protease inhibitors, especially
when it is combined with other anti-HIV medications
that a patient's virus is still at least partially
sensitive to.
Aptivus/ritonavir
works best when it is combined with anti-HIV
drugs that the virus is still sensitive to.
However, this can be challenging for HIV-positive
people who have tried and failed several anti-HIV
drug regimens in the past. Drug resistance tests,
such as genotypic assays and phenotypic assays,
can be very useful in figuring out which anti-HIV
drugs the virus is still likely to respond to.
Drug-resistance tests are recommended when putting
together a regimen that contains Aptivus/ritonavir.
In clinical trials, Aptivus/ritonavir worked
best when it was combined with Fuzeon
(enfuvirtide; T-20), particularly in people
who had not been on Fuzeon in the past.
Drug
and Food Interactions
Absorption of tipranavir
increases when taken with a high-fat meal. Antacids
reduce absorption of tipranavir, requiring timing
adjustments of antacid use.
Tipranavir/ritonavir at
the recommended dosage is an inhibitor of CYP
3A and may thus increase plasma concentrations
of agents that are primarily metabolized by
this enzyme. Coadministration of tipranavir/ritonavir
with drugs that are highly dependent on CYP
3A for clearance are contraindicated. These
drugs include amiodarone, bepridil, flecainide,
propafenone, quinidine, rifampin, dihydroergotamine,
ergonovine, ergotamine, methylergonamine, cisapride,
St. John's wort, lovastatin, simvastatin, pimozide,
midazolam, and triazolam.
When used with other antiretrovirals
in vitro, tipranavir was shown to be additive
to antagonistic with other PIs, generally additive
with non nucleoside reverse transcriptase inhibitors
(NNRTIs) and nucleoside reverse transcriptase
inhibitors (NRTIs), and synergistic with the
fusion inhibitor enfuvirtide (Fuzeon).
Patients should tell their
doctor about any other medications they are
taking, including prescription, nonprescription
(over-the-counter), or herbal medications. It
is particularly important for doctor s to know
if a patient is allergic to sulfa drugs, because
people with sulfa allergies may be at a higher
risk of having an allergic reaction to tipranavir.
Potential
Adverse Events and Side Effects
WARNING
APTIVUS CO-ADMINISTERED WITH 200 MG RITONAVIR
HAS BEEN ASSOCIATED WITH REPORTS OF BOTH
FATAL AND NON-FATAL INTRACRANIAL HEMORRHAGE.
(SEE WARNINGS)
APTIVUS
CO-ADMINISTERED WITH 200 MG RITONAVIR
HAS BEEN ASSOCIATED WITH REPORTS OF CLINICAL
HEPATITIS AND HEPATIC DECOMPENSATION INCLUDING
SOME FATALITIES. EXTRA VIGILANCE IS WARRANTED
IN PATIENTS WITH CHRONIC HEPATITIS B OR
HEPATITIS CO-INFECTION, AS THESE PATIENTS
HAVE AN INCREASED RISK OF HEPATOTOXICITY.
(SEE WARNINGS)
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Like all anti-HIV drugs,
tipranavir may cause some unwanted side effects.
The most common side effects are diarrhea, nausea,
fatigue, headache, and vomiting.
Adverse effects leading
to discontinuation of treatment were reported
in 7.8 percent of individuals receiving tipranavir.
Other adverse effects include rash, elevated
lipid levels, fat redistribution, and immune
reconstitution syndrome. Women using estrogens
may have an increased risk of non serious rash.
Individuals with hemophilia may have increased
risk of bleeding.
Tipranavir
in combination with ritonavir has been associated
clinical hepatitis (liver inflammation) and
hepatic decompensation, including some fatalities.
Extra vigilance is warranted in individuals
with advanced HIV disease or those with chronic
hepatitis B or hepatitis C co-infection [with
HIV] as these individuals have an increased
risk of hepatotoxicity. Symptoms of hepatitis
include fatigue, malaise, anorexia, nausea,
jaundice, bilirubinemia, acholic stools, liver
tenderness, or hepatomegaly.
Dosing
Information
Tipranavir is available
in 250 mg soft gel capsules and is taken with
ritonavir. The recommended dosing regimen is
500 mg tipranavir taken with 200 mg ritonavir
twice daily.
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