Invirase should be taken with low doses of Norvir (ritonavir), another protease inhibitor that boosts Invirase levels in the body (Invirase suffers from absorption problems, meaning that only a small amount of the drug is absorbed into the bloodstream from the gut). Invirase (1,000mg twice daily) combined with Norvir (100mg twice daily) was approved by the FDA in December 2003 for this purpose.

Invirase is broken down (metabolized) by the liver, like many medications used to treat HIV and AIDS. This means that Invirase can interact with other medications. Invirase can lower or raise the levels of other medications in the body. Similarly, other medications can lower or raise the levels of Invirase in the body. While many interactions are not a problem, some can cause your medications to be less effective or increase the risk of side effects.

The following medications should not be taken while you are being treated with Invirase:

• 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)

• Corticosteroids: Flovent o Flonase (fluticasone)

• Pulmonary hypertension medications: sildenafil (Revatio)

• 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)

• Antidepressants: Desyrel (trazadone)

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

• Herbal products: St. John's wort, garlic capsules

• Enlarged prostate: Uroxatral (alfuzosin)

Anticonvulsants, such as Tegretol ( carbamazepine), Luminal (phenobarbital), and Dilantin (phenytoin), may decrease the amount of Invirase in the bloodstream. Invirase/Norvir should be used with caution if combined with these medications.

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. Invirase/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 Invirase/Norvir. Revatio (sildenafil) and Invirase/Norvir should not be used together.

Invirase/Norvir can increase blood levels of the antidepressant Desyrel (trazadone), which can increase the possibility of experiencing Desyrel side effects. The two should not be used together. Invirase/Norvir can also increase the blood levels of the tricyclic antidepressants Elevil (amitriptyline) and Tofranil (imipramine). Providers should monitor blood levels of these antidepressants if combined with Invirase/Norvir.

Short-term side effects include appetite loss, headaches, feeling crummy (malaise), diarrhea, nausea, and vomiting. Very often, these side effects improve within a few months/weeks of starting Invirase.

HIV drug regimens containing protease inhibitors, including Invirase, can cause increased fat levels (cholesterol and triglycerides) in the blood, 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), and diabetes. These side effects of HIV drug therapy are reviewed in our lessons on Lipodystrophy, Facial Lipoatrophy, and Risks To Your Heart (Hyperlipidemia). 

In rare cases, Invirase/Norvir can increase the risk of heart rhythm disturbances, called QT interval prolongation or a condition called torsades de pointes. The abnormalities—which can be detected using an electrocardiogram—can also lead to interrupted electrical impulses to the heart muscle, technically referred to as heart block. Both conditions can lead to lightheadedness, fainting or abnormal heart beats. In some cases, torsades de pointes can progress to life-threatening irregular heart beat known as ventricular fibrillation. People who already have these conditions should not use Invirase/Norvir. 

$680.00

Product Code: INV3YECU7