Prezista – brand name

darunavir – generic name

TMC114 - former name during development

Prezista belongs to a class of HIV drugs called protease inhibitors (PIs).

Prezista and the other PIs work by blocking protease, a protein that HIV needs to make more copies of itself. This may slow down HIV disease.

The Food and Drug Administration (FDA) has approved Prezista for use in combination with other HIV drugs for the treatment of HIV infection in adults and children over six years old.

Prezista can be used by people who are just starting treatment and have never taken HIV drugs. It can also be used by people who have been on treatment and have HIV that is resistant to other HIV drugs.

Prezista comes in 75 milligram (mg), 150 mg, 300 mg, 400 mg, and 600 mg tablets. Prezista must be combined with a small (“booster”) dose of Norvir (ritonavir) in order to work properly.

There are two approved adult doses:

• For people new to treatment (treatment naïve): Two 400 mg Prezista tablets plus one 100 mg Norvir capsules once a day
• For people who have been on HIV treatment before (treatment experienced): One 600 mg Prezista tablet plus one 100 mg Norvir capsule twice a day
  

No dose adjustment is necessary for people with mild to moderate liver disease, but Prezista is not recommended for people with severe liver impairment.

Children’s dosing is based on body weight.

Prezista must be used with other HIV medications (in addition to Norvir) to treat HIV.

Prezista should be taken with food (meal or snack).

Prezista contains sulfonamide, which can cause allergic reactions in some people. If you are allergic to sulfa drugs, tell your health care provider. You may still be able to take Prezista.

As with all HIV drugs, it is important to take Prezista as prescribed by your health care provider. Missing or skipping doses can cause blood levels of Prezista to fall too low and the virus can become resistant to it. This may cause Prezista and other HIV drugs you are taking to stop working.  

Prezista can be used by people who are taking HIV drugs for the first time.

Prezista can also be used by people whose HIV has become resistant to other HIV drugs. Because it may work against HIV that is resistant to the other PIs, Prezista may be a good choice for people who need to switch therapies because of PI resistance.

In people with drug resistance, Prezista (plus Norvir) works best when it is combined with at least one other active HIV drug (a drug that their virus does not have resistance to). You and your health care provider should use resistance testing and your treatment history to help guide the use of Prezista and to determine which drugs will work best for you.

If your virus develops resistance to Prezista, it may stop working or may not work as well for you. You also may not get as much benefit from other PIs.

Sometimes taking more than one medication can cause drug interactions. This can lead to the drugs not working as well or an increased risk of side effects.

Prezista interacts with many other drugs including some other HIV drugs, anti-fungals, TB drugs, cholesterol-lowering medications, antihistamines, sedatives, antidepressants, drugs to treat erectile dysfunction (ED), and methadone.

Taking Prezista with these drugs can change the amount of each drug in your blood. Your health care provider may need to either adjust the doses of your drugs to avoid under- or overdosing or to change the drugs you currently take.

Do not take Prezista with:

• Crixivan (indinavir)
• Kaletra (lopinavir/ritonavir)
• Invirase (saquinavir)
• D.H.E.45, Migranal (dihydroergotamine)
• Ergonovine
• Wigraine, Ergostat, Cafergot, Ergomar (ergotamine)
• Methylergonovine
• Propulsid (cisapride)
• Orap (pimozide)
• Oral midazolam
• Halcion (triazolam)
• Rifadin, Rifater, Rifamate (rifampin)
• Mevacor, Altoprev, Advicor (lovastatin)
• Pravachol, (pravastatin)
• Zocor, Simcor, Vytorin (simvastatin)
• Products containing St. John's wort
  

If you are taking Lipitor (atorvastatin) or Crestor (rosuvastatin), your doctor may want to reduce your dose or change to a drug such as Lescol (fluvastatin) that is less likely to interact with Prezista.

Caution is needed when Prezista is used with Sustiva (efavirenz) and the ED drugs Viagra (sildenafil), Levitra (vardenafil), and Cialis (tadalafil) because Prezista can change the blood levels of these drugs.

Prezista may decrease the effectiveness of birth control pills, so alternative birth control methods should be used.

This is not a complete list of medications. Because there are so many possible drug interactions with Prezista, it is very important to go over all your medications with your health care provider. Be sure your health care provider knows about all the medications you are taking (including over-the-counter, prescription, street drugs, and herbs), even if you only use them occasionally.

For more information and additional resources to check interactions among the specific drugs you are taking, see The Well Project info sheet on drug interactions or go to:
 
http://www.hiv-druginteractions.org
OR
http://hivinsite.ucsf.edu/insite?page=ar-00-02

In studies, Prezista was generally well tolerated. It is possible that long-term side effects could show up later.

If you do experience any side effects from Prezista, they are likely to be temporary and go away as your body adjusts to the medication. If you experience any of the side effects listed below, call your doctor for advice. Do not just stop taking your medication.

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Abdominal pain
• Headaches

More serious side effects:

• Liver toxicity: Symptoms are elevated liver enzymes (ALT and AST), yellowing of the skin or eyes (jaundice), excessive tiredness, and loss of appetite. Liver function tests should be done when starting Prezista and checked often throughout treatment. Liver problems are more likely to occur in people co-infected with hepatitis B or C.
• Lipodystrophy: Symptoms may include metabolic changes such as increased blood sugar (glucose), elevated blood lipids ( cholesterol and triglycerides), and fat gain or loss in certain areas. The exact causes of lipodystrophy are not known, but may include HIV and/or HIV drugs. For more information on lipodystrophy, see The Well Project info sheet.
• Skin rash: In rare cases, a life-threatening skin reaction called Stevens-Johnson syndrome develops. Symptoms may include a severe rash, blisters, mouth sores, swelling, fever, and weakness. Swelling of the face, lips, and tongue has also been reported. Call your health care provider immediately if you experience these symptoms.
• Hypersensitivity reaction: Prezista contains sulfonamide, which can cause an allergic reaction in some people. If you are allergic to Bactrim or Septra, or if you have been told that you are allergic to sulfa, you should use caution when taking Prezista.

If you experience persistent, unusual, or serious side effects, call your doctor right away.

Prezista is a newer protease inhibitor, and has not been studied in as many people as the older HIV drugs.

The company that makes Prezista conducted a study called GRACE (Gender, Race And Clinical Experience) to see if there were gender and race differences in response to treatment with Prezista combined with other HIV drugs. The GRACE study showed that after 48 weeks of treatment, there were no significant differences in safety or effectiveness between women and men.

GRACE was a landmark study because it was designed to enroll mostly women, African Americans and Latinos. In the US, women are increasingly affected by HIV, making up more than one quarter of all new HIV/AIDS diagnoses, with African American and Latina women representing 79 percent of HIV+ women. Despite the increasing numbers of HIV+ women, they have been under-represented in clinical trials.

In recent HIV studies of treatment-experienced HIV+ people, on average, women accounted for about 10 percent of the patients being studied. GRACE was able to enroll 67 percent women and 84 percent people of color. As well as showing that women and men respond similarly to Prezista, the GRACE study demonstrated that it is possible to recruit large numbers of women, African Americans and Latinos into clinical trials.

It is very important for women to get involved in HIV drug research and clinical trials. Historically, women's health issues have not been thoroughly researched in HIV+ women. This needs to change – our bodies are different from men’s bodies, and our reactions to medications can be different, too. You can help by getting involved and participating. If you are interested in learning about or enrolling in clinical trials, see The Well Project fact sheets on clinical trials.

Studies have shown that pregnant women who use HIV drugs can greatly reduce the risk of passing HIV on to their babies. However, there have been no formal studies on the use of Prezista during pregnancy. Prezista should be used in pregnant women only if the potential benefit outweighs the potential risk to the baby.

An Antiretroviral Pregnancy Registry has been established to collect information on pregnant women who take HIV drugs, including Prezista. If you are pregnant and taking Prezista or other HIV drugs, your doctor can register you by calling 1-800-258-4263 or going to www.apregistry.com. 

It is not known whether Prezista passes into breast milk. HIV+ women should not breast-feed because their babies could be infected with HIV through the breast milk. 

Check with your doctor about the best treatment options for you and your baby if you are pregnant or thinking of getting pregnant.

Click this link for more information about pregnancy.

People who are starting HIV treatment for the first time may develop Immune Reconstitution Syndrome or IRS (also called Immune Reconstitution Inflammatory Syndrome or IRIS). IRS can happen as a result of the immune system getting stronger and responding to an HIV-related infection such as Mycobacterium avium infection (MAC), cytomegalovirus (CMV), Pneumocystis jirovecii pneumonia (PCP), or tuberculosis (TB). People may have been treated for these infections in the past or not even know they have them. If you notice any unusual symptoms soon after starting HIV drugs, let your doctor know right away so you can be evaluated and, if necessary, treated.