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Basic Informations

Prezista is an HIV medication. It is in a category of HIV medicines called protease inhibitors. Prezista prevents cells infected by HIV from producing new virus. This reduces the amount of virus in your body.

Prezista must be used with low-dose Norvir (ritonavir) and in combination with other HIV drugs.

Prezista, manufactured by Tibotec Therapeutics, a division of Centocor Ortho Biotech Products, LP, was initially approved by the U.S. Food and Drug Administration (FDA) on June 23, 2006, for treatment-experienced HIV-positive adults. It was approved for HIV-positive people beginning treatment for the first time on October 22, 2008.

Drugs Interactions

Because of the ways Prezista and Norvir are metabolized (broken down) in the body, they can interact with many other medications used to treat HIV, AIDS-related complications, and other diseases. Prezista/Norvir may cause blood levels of other medications to be become too low (which can decrease their effectiveness) or high (which can increase the risk of side effects). Similarly, other medications may cause blood levels of Prezista and/or Norvir to become too low or high.

Tell your doctors and pharmacists about all medicines you take. This includes those you buy over-the-counter and herbal or natural remedies, such as St. John's wort. Bring all your medicines when you see a doctor, or make a list of their names, how much you take, and how often you take them. Your doctor can then tell you if you need to change the dosages of any of your medications.

The following medications should not be taken while you are being treated with Prezista/Norvir (this list includes medications that are contraindicated—should not be taken together—according to both the Prezista and Norvir packaging information):

  • Antifungals: Vfend (voriconazole)

  • Anti-seizure medications: Tegretol (carbamazepine), Luminal (phenobarbital), Dilantin ( phenytoin)

  • Acid reflux/heartburn medications: Propulsid (cisapride)

  • Antibiotics: Rifadin (rifampin)

  • Antimigraine medications: Methergine, Methylergometrine (methylergonovine); Ergostat, Cafergot, Ercaf, Wigraine (ergotamine); Ergotrate, Methergine (ergonovine); or D.H.E. 45, Migranal (dihydroergotamine)

  • Antihistamines: Hismanal (astemizole) or Seldane (terfenadine)

  • Cholesterol-lowering drugs (statins): Zocor (simvastatin) and Mevacor (lovastatin)

  • Heart medications: Cordarone (amiodarone), Vascor (bepridil), Tambocor (flecainide), Rythmol (propafenone), or Quinaglute/Quinidex (quinidine)

  • Antipsychotics: Orap (pimozide)

  • Sedatives: Versed (midazolam) and Halcion (triazolam)

  • Enlarged prostate: Uroxatral (alfuzosin)

  • Pulmonary Hypertension: sildenafil, used as Revatio

  • Herbal products: St. John's wort

HIV protease inhibitors can interact with Prezista/Norvir. Kaletra (lopinavir/ritonavir) and Invirase (saquinavir) can significantly decrease blood levels of Prezista, hence it is not recommended that Prezista be combined with Kaletra or Invirase. Taking Prezista and Crixivan together can cause the levels of both drugs to increase in the bloodstream. Prezista/Norvir does not appear to increase or decrease blood levels of Reyataz (atazanavir), nor does Reyataz appear to increase or decrease blood levels of Prezista/Norvir. In turn, it may be possible to combine these two PIs.

HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs) can also interact with Prezista/Norvir. Prezista/Norvir can increase levels of Sustiva (efavirenz) [and to a lesser extent Viramune (nevirapine)] in the blood. Combining Prezista/Norvir with Sustiva should be done with caution.

Prezista/Norvir can increase levels of Viread (tenofovir), a nucleotide reverse transcriptase inhibitor, in the blood. However, these two drugs can be combined without any dose adjustments (although it may be necessary to watch carefully for kidney damage, a potential side effect of Viread). Videx/Videx EC (didanosine) must be taken on an empty stomach. In turn, if Videx/Videx EC is used in the same regimen as Prezista/Norvir, it should be taken one hour before or two hours after Prezista/Norvir (which should be taken with food).

Prezista/Norvir can interact with some medications used to treat thrush (candidiasis) and other fungal infections. Prezista/Norvir increases Nizoral (ketoconazole) and may increase Sporanox (itraconazole) levels in the bloodstream. For people taking Prezista/Norvir who also need to take Sporanox or Nizoral, the daily dose of Sporanox or Nizoral should not exceed 200mg. It is also possible that Prezista/Norvir decreases Vfend (voriconazole) levels in the blood (Vfend should not be taken if you are on an HIV drug regimen that contains Norvir).

Prezista/Norvir can interact with some medications used to treat TB, MAC, and other bacterial infections. Prezista/Norvir raises Biaxin (clarithromycin) levels in the bloodstream. The dose of Biaxin does not need to be decreased, although this is recommended in people with altered kidney function. Prezista/Norvir can also increase Mycobutin (rifabutin) levels in the bloodstream (Mycobutin can also increase Prezista levels in the bloodstream). If Mycobutin is taken at the same time as Prezista/Norvir, it is recommended that the Mycobutin dose be reduced to 150mg every other day. Prezista/Norvir should not be used with Rifadin (rifampin), a common antibiotic used to treat TB.

Prezista/Norvir may interact with calcium channel blockers, medications used to treat heart disease. Studies of Prezista/Norvir combined with calcium channel blockers have not yet been conducted. Healthcare providers should be cautious when prescribing Prezista/Norvir with either Cardizem (diltiazem), Plendil/Lexxel (felodipine), Cardene (nicardipine), Sular (nisoldipine), or Calan/Verelan (verapamil). Prezista/Norvir can increase the blood levels of the heart medications Vascor (bepridil), lidocaine, Quinidex (quinidine) and Cardarone (amiodarone). These medications should be used with caution if taken with Prezista/Norvir and monitoring blood levels of these drugs is recommended, if available. Prezista/Norvir can also significantly increase blood levels of Lanoxin (digoxin). The lowest dose of Lanoxin should initially be used and monitoring Lanoxin blood levels is recommended.

Prezista/Norvir can decrease levels of the blood thinner Coumadin (warfarin) in the bloodstream. Conducting blood coagulation (clotting) testing may be necessary.

Prezista/Norvir may increase blood levels of Norpramin (desipramine), a drug used to treat depression. The dose of Norpramin may need to be decreased. Prezista/Norvir may also decrease levels of Zoloft (sertraline) and Paxil (paroxetine). It may be necessary to increase Zoloft of Paxil dosing if also using Prezista/Norvir.

Cholesterol-lowering drugs, also known as "statins," can interact with Prezista/Norvir. There are two statins that should not be used with Prezista/Norvir: Zocor (simvastatin) and Mevacor (lovastatin). Levels of these two drugs can become significantly increased in the bloodstream if they are combined with Prezista/Norvir, which increases the risk of side effects. The statin believed to be the safest in combination with Prezista/Norvir is Lescol (fluvastatin). It is also possible to take Prezista/Norvir with Lipitor (atorvastatin), or Crestor (rosuvastatin) although Prezista/Norvir can increase the level of these drugs in the bloodstream (if Lipitor or Crestor are prescribed, it's best to begin treatment with the lowest possible dose of the drug and then increase the dose if necessary or else use a different drug.) While the FDA-approved packaging information for Prezista suggests that Pravachol (pravastatin) can also be used, Tibotec does not recommend combining Pravachol with Prezista/Norvir.

Prezista can increase blood levels of cochicine, which is used to treat gout. Lower doses of colchicine are recommended, and the two drugs should not be used together in people with liver or kidney impairment.

Neoral, Sandimmune, Gengraf (cyclosporine), Prograf (tacrolimus), Rapamune (sirolimus) are all examples of immune-suppressants, often prescribed for patients who have undergone an organ/tissue transplant. Prezista/Norvir can increase levels of these drugs in the blood. In turn, it is necessary to carefully monitor blood levels of these drugs if they are combined with Prezista/Norvir.

Prezista/Norvir can increase blood levels of Advair, Flovent, or Flonase (fluticasone), the inhalable medications that are used to treat allergies and asthma. In turn, these drugs may decrease blood levels of Prezista/Norvir. Alternatives to these drugs should be considered, especially for long-term use. Prezista can increase blood levels of an asthma medication called Serevent (salmeterol), a drug that is used to open the air passages in the lungs during an asthma attack. This can result in heart rhythm problems. Use of the two drugs together is not recommended.

Another painkiller, methadone, commonly used to treat drug heroin addiction, can interact with Prezista/Norvir. Methadone levels in the bloodstream can decrease when combined with Prezista/Norvir. Because of this, it might be necessary to increase the dose of methadone.

Desyrel (trazodone) is used to treat depression. Prezista/Norvir can increase blood levels of this drug, leading to an increase risk of Desyrel side effects. Using a lower dose of Desyrel may be necessary.

Prezista/Norvir decreases the amount of oral contraceptives (taken by women to help avoid pregnancy) in the bloodstream. This means that there may be a higher risk of becoming pregnant if Prezista/Norvir and oral contraceptives are taken at the same time. To reduce the risk of pregnancy, barrier protection (e.g., condoms) should be used.

There is a class of drugs, known as PDE-5 inhibitors that are used to treat both erectile dysfunction and pulmonary arterial hypertension. Their brand names differ, depending on their use. Prezista/Norvir can significantly increase blood levels of these drugs.

When used to treat erectile dysfunction, it is best to use a lower dose of Viagra (sildenafil), Levitra (vardenafil) and Cialis (tadalafil) in order to reduce the risk of side effects. When used to treat pulmonary arterial hypertension, the dose of tadalafil (Adcirca) must be reduced if combined with Prezista/Norvir. Revatio (sildenafil) and Prezista/Norvir should not be used together.

Tracleer (bosenstan) is another type of drug used to treat pulmonary arterial hypertension, called an endothelin receptor antagonist. Prezista/Norvir can increase Tracleer blood levels, so the dose of Tracleer should be reduced.

Side Effects

The most common side effects reported by patients taking Prezista and Norvir in clinical trials included diarrhea, nausea, headache, and abdominal pain. Some patients receiving Prezista/Norvir experienced skin rashes; most were mild-to-moderate. If a severe rash occurs while taking Prezista/Norvir, patients should contact their healthcare providers immediately.

Prezista, a sulfa-containing drug, should be used with caution in patients with a known sulfa allergy.

Some people may experience large increases in their lipid levels (triglycerides and cholesterol) while being treated with protease inhibitors. However, it is not yet known what effect, if any, Prezista will have on lipids.

Diabetes and high blood sugar may occur in people who take Prezista or other protease inhibitors.

HIV drug regimens containing protease inhibitors, including Prezista/Norvir, may cause abnormal body-shape changes (lipodystrophy; including increased fat around the abdomen, breasts, and back of the neck, as well as decreased fat in the face, arms, and legs). These side effects of HIV drug therapy are reviewed in our lesson on lipodystrophy.

HIV medications, such as Prezista, can increase the risk of bleeding in hemophiliacs.

Drug-induced hepatitis (liver injury) has been reported in people taking Prezista. This usually occurred in people who had extremely low CD4 cells, were taking multiple other medications and who were also infected with hepatitis B virus (HBV) and/or hepatitis C virus (HCV). People taking Prezista who are coinfected with HBV or HCV, or who have a history of liver damage, should have their liver function closely monitored by their healthcare providers. Stopping Prezista treatment may be necessary, in consultation with a healthcare provider, in the case of abnormal liver enzymes or symptoms of liver damage (i.e. fatigue, nausea, yellow eyes and skin, dark urine and liver tenderness).