|lopinavir and ritonavir
Some of these medicines must be used with ritonavir.
How It Works
Protease inhibitors (PIs) are
antiretroviral medicines. They prevent
HIV from multiplying, reducing the amount of virus in
your body. When the amount of virus in the blood is kept at a minimum, the
immune system has a chance to recover and grow
Why It Is Used
The use of three or more
antiretroviral medicines (highly active antiretroviral therapy, or HAART) is the usual treatment for HIV infection.
combination of medicines used for HAART will depend on your health, other
conditions you might have (such as
hepatitis), and results of testing. Talk to your
doctor about the best treatment plan for you.
suggest the following for people with HIV:1, 2, 3
- When considering treatment, experts currently consider your CD4+
cell count and the presence or absence of symptoms more important than your
- If your
CD4+ count is below 500 cells per microliter (mcL),
treatment is recommended to help keep your immune system healthy and
to prevent AIDS.
- If your CD4+ cell count is greater than 500, you may want to consider treatment.
- If treatment is not started, your condition will be
monitored with frequent CD4+ cell counts.
- If you have symptoms of
HIV or AIDS, doctors recommend starting treatment, whatever your CD4+ cell
- If you are pregnant, you should be treated to prevent your unborn
baby (fetus) from becoming infected with HIV.
you also have
hepatitis B and are starting treatment for it, you
should begin treatment for HIV as well.
You may also want to start HIV treatment if your sexual partner does not have HIV. Treatment of your HIV infection can help prevent the spread of HIV to your sexual partner.3
The U.S. National Institutes of Health recommend one of the following programs for people who begin treatment for HIV:1
HIV: When Should I Start Antiretroviral Medicines for HIV Infection?
HIV: Taking Antiretroviral Medicines
How Well It Works
- Reduces viral loads, which can lead to stable
or increased CD4+ cell counts, a sign that the immune system is still able to
- Decreases the
number and severity of opportunistic infections.
- Reduces or
prevents the occurrence of
resistance to the medicines.
- Prolongs life.
Antiretroviral therapy can also decrease symptoms of HIV
infection, such as fever and weakness, and help the person gain weight.
The rate at which antiretrovirals decrease viral loads is affected
CD4+ cell counts at the beginning of
- Viral load at the beginning of
- The dosage of the medicines.
- Whether the
medicines are taken exactly as prescribed.
- Whether antiretroviral
medicines have been taken before.
- Whether any
opportunistic infections are present.
To prevent serious medicine
interactions or a decrease in medicine effectiveness, be sure to learn
which medicines should not be taken with PIs and other antiretroviral
PIs may cause:
- An increase in blood
- Changes in the distribution of body fat.
- Nausea, diarrhea, and vomiting.
- An increase in
Liver problems, especially if you
have liver disease.
Indinavir causes kidney stones in 5% of people who use it. The risk of kidney stones can
be reduced by drinking at least
48 fl oz (1.4 L) of fluid each
Certain protease inhibitors (fosamprenavir, indinavir, and lopinavir/ritonavir) have been associated with a small increase in the risk of having a heart attack.
Side effects of any combination medicine can include the
side effects of any of the single medicines in the combination.
Report all side effects to your doctor at your next visit. He or she can
adjust your dose or give you other medicines to reduce side effects. Some mild
side effects, such as nausea, improve as your body adjusts to the
See Drug Reference for a full list of side effects.
(Drug Reference is not available in all systems.)
What To Think About
Many people think antiretroviral
medicines always have severe side effects. In fact, only a few people
experience severe or dangerous side effects.
Food increases the
absorption of atazanavir, nelfinavir, and darunavir.4
Certain acid-reducing medicines, such as omeprazole or famotidine, should not
be taken at the same time as atazanavir. Before you take protease inhibitors (PIs), be sure to tell your doctor about any
other medicines you are taking.
Resistance to PIs develops more frequently if these medicines are used
alone or are not taken exactly as prescribed.
Lopinavir is combined with a
low dose of ritonavir to inhibit the breakdown of lopinavir in the body. This
delayed breakdown of lopinavir increases its effectiveness.
PIs are expensive. They can
cost up to two times more than nucleoside/nucleotide reverse transcriptase
Things to think about when choosing a
combination of medicines include:
- The ability of the medicines to reduce your
- The likelihood the virus will develop resistance to a
certain class of medicine. If you have already been treated with a certain
antiretroviral medicine, you may already know whether you are resistant to
medicines in that class.
- Side effects and your willingness to
- The cost of treatment.
Do not use the nonprescription herbal supplement
St. John's wort while you are taking a protease inhibitor, because St. John's
wort can interfere with how well these medicines work.
to your doctor about whether you can eat grapefruit or drink grapefruit juice
while you are taking protease inhibitors. It may increase the side effects of
some of these medicines.5
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
U.S. Department of Health and Human Services (2009). Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Available online: http://www.aidsinfo.nih.gov/contentfiles/AdultandAdolescentGL.pdf.
Hammer, Scott M, et al. (2008). Antiretroviral
treatment of adult HIV infection: 2008 recommendations of the International
AIDS Society USA Panel. JAMA, 300 (5):
U.S. Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents (2011). Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents. Available online: http://www.aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf.
Atazanavir (Reyataz) and emtricitabine (Emtriva) for
HIV infection (2003). Medical Letter on Drugs and Therapeutics, 45(1169): 90-92.
Tatro DS (2004, January). Keeping up: Interactions of
herbal supplements and grapefruit juice with medications used to treat HIV
infection. Drug Facts and Comparisons News: 3-5.