Protease Inhibitor: Norvir (Ritonvir)

PROTEASE INHIBITOR:
NORVIR (RITON AV I R)

What are Protease Inhibitors?
P rotease inhibitors are a new type of antiretroviral (a drug that
stops the reproduction of HIV in your body). Protease drugs
work by blocking a part of HIV called protease. With protease
blocked, HIV makes copies of virus that can't infect new cells.
Studies (clinical trials) of protease inhibitors have shown that these
drugs, taken alone or in combination with other antiretroviral
drugs (AZT, ddl, ddC, d4T, 3TC ), can lower viral load (the
amount of HIV in your blood) and raise T-cells (CD4 cells). The
greatest effect has been seen in people taking combination therapy.
However, it's important to remember that more studies are needed
to better understand how to use these drugs.
When Should I Start Taking Protease Inhibitors?
N o one knows exactly when is the best time to begin taking
protease inhibitors. Several studies of people who have low Tcells (100 or lower) have found that those who add a protease
inhibitor along to other HIV medicine get about half as sick as
those who do not. Based on these results, if you have: 1) low Tcells, 2) high viral load, 3) symptoms of illness, and/or 4) have had
HIV disease for a long time, you may want to talk with your doctor
about starting a combination that inclues a protease inhibitor.
Doctors have not yet confirmed that taking these drugs early
in HIV disease-when T-cells are high and viral load is lowwill help prolong life or prevent the development of AIDS. In
theory, starting a protease inhibitor when viral load is low will
allow the drug to be more effective.

Norvir (also called Ritonavir):
Dose
600 mg every twelve hours. People taking Norvir are advised to take
up to two weeks to get up to the full dose. This is to avoid nausea,
vomiting and diarrhea. The recommended starting schedule is as
follows: On days I & 2 take 300 mg twice daily; days 3 & 4 take 400
mg twice daily; days 5 & 6 take 500 mg twice daily; and if there are no
problems take 600 mg twice daily on day 7. If you are having problems
with Norvir on days 5 & 6, you can stay on 500 mg twice daily.
To lessen stomach upset and improve absorption of the drug into
your body, Norvir should be taken on a full stomach, preferably a meal
high in fat (e.g. lean red meat, peanut butter, avocado, cheese, bread
with butter, whole or 2 percent milk products). Each capsule should be
taken separately with a good drink of milk or spoonful of yogurt.
Norvir has been studied in combination with AZT/ddC and
AZT/3TC. In these combinations, and probably most others, Norvir has
reduced the amount of HIV in the blood for up to a year. If resistance
to Norvir should occur, cross-resistance may be a serious problem. HIV
resistant to Norvir may be resistant to all the other protease inhibitors
now on the market.
Storage
Norvir must be kept in the refrigerator.
Side Effects
The most common side effects are nausea, diarrhea, vomiting, stomach
pain, taste change, fatigue, mild to severe skin sensitivity and
numbness around the mouth. Some people report that the side effects
are worse during first few weeks of taking the drug and then taper off.

Can Drug Resistance Occur with
Protease Inhibitors?
Yes. HIV eventually learns to work around the
effect of the drug. This is called drug resistance.
Resistance causes the drug to work less well or not
to work at all. Resistant HIV may not go away,
even if you stop taking the drug. Also, developing
HIV that has resistance to one anti-protease drug
will often mean that the HIV is resistant to other
such drugs as well. This is called cross-resistance.
Some studies show that taking protease
inhibitors in combination with other anti-HIV
drugs may greatly reduce the chance of
developing resistance by further controlling the
virus. To avoid or delay the development of drug
resistance, make sure you take the drugs properly.
Skipping doses, taking lower than prescribed
doses, not following food guidelines and not
taking the drugs on schedule weakens the drugs'
effect. HIV can then reproduce more. The more
HIV reproduces, the better its chance to develop
drug resistance. If you think that you are not able
to follow the treatment routine which you and
your doctor have put together, then you might
want to wait until you are better prepared to take
the drugs properly.

NORVIR should NOT
BE TAKEN with:
Generic name Brand name
alprazolam Xanax
amiodarone Cordarone
astemizole Hismanal
bepril Vascor
bupropion Wellbutrin
cisapride Propulsid
clorazepate Tranxene
clozapine Clozaril
diazepam Valium
dihydroergotamine D.H.E. 45
encainide Enkaid
ergotamine Cafergot &
others
estazolam ProSom
flecainide Tambocor
flurazepam Dalmane
merperidine Demerol
midazolam Versed
pimozide Orap
piroxican Feldene
propafenone Rythmol
propoxyphene Darvon
quinidine
rifabutin Mycobutin
terfenadine Seldane
triazolam Halcion
zolpidem Ambien

Drug Interactions
Norvir raises the blood levels of many other drugs. For
example, Norvir increases the amount of Methadone
and Ecstasy in your your blood There are at least 30
different drugs that should not be taken with Norvir.
There are many more that will require a change in
dosing when taken with Norvir. Some of these drugs
are commonly used by people with HIV. It is very
important to talk with your doctor about each
medication, including street drugs, you take or will
take to make sure that it is safe to take them with
Norvir. The combination of some of these drugs with
Norvir can be dangerous, so take this seriously.
Cost
Norvir sells for about $8,000.00 a year. Most Medicaid
programs and private insurers cover the cost of the
drug. Norvir also is paid for by the ADAP program in
New York and many other states. Abbott Labs, the
maker of Norvir, runs a patient-assistance program for
people who cannot afford the drug and who meet
certain eligibility requirements. For more information,
call 1-800-659-9050.
Availability
Norvir is an approved drug and is available through
any pharmacy.

For other Fact Sheets or for more information, contact GMHC, Department of Treatment Education and Advocacy, 119 West 24th Street, New York, NY 10011 [phone]