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Norvir - ritonavir

General Information Ritonavir is almost always used as one component of a multidrug combination to suppress the human immunodeficiency (HIV) viral load.  Additionally it is seldom used as an active drug itself anymore.  Its used as booster of other protease inhibitors.
Specifics Ritonavir is a well-respected and well-tolerated antiviral medication.  It has a long track record of effectiveness and safety.

Ritonavir works by inhibiting the production of HIV's proteins.  It is classified as a protease inhibitor (PI).

Dosing Generally ritonavir is taken as 1-2 of the 100 mg gel caps once or twice a day depending on which drug it is being used to boost.  Read the label on the bottle carefully to determine the dosage that you were prescribed.

You can take low dose ritonavir with or without food but food will prevent it from possibly upsetting your stomach.  There is a liquid form available which tastes pretty bad, but the liquid is easier to swallow for some people than the gel caps.

It is best to store ritonavir in a refrigerator, but it may be left outside the refrigerator for up to 30 days at room temperature below 78 degrees Fahrenheit.  If you travel with it, consider carrying it in a "cool pack" or a cooler.

(this refers to your willingness, ability, and actual performance in taking your medications)

For further information and tips on adherence, go to the Adherence section of this site

As with any antiviral drug or antibiotic, try not to ever miss a dose.  If you miss a dose and notice that you have done so within a few hours of its scheduled time, you may take the dose as usual and take the next dose at its regular time. 

Do not change the dose of ritonavir without speaking to your healthcare provider.

If you miss more than one dose, look at the reasons why you missed them and come up with a plan to avoid it in the future.  For example, if you fell asleep too early, take the medicine earlier in the evening, with your later meal, set an alarm, or have someone appointed to wake you up for your medicine.  

It is strongly recommended that you consider using weekly pill boxes and arrange all of your doses a week in advance.  Buy a small pill box so that you can carry a dose or two of your medicines with you in case you are away from home.

Possible Side Effects
The package insert for most drugs including ritonavir is often overwhelming and scary with perhaps an overemphasis on side effects.  We have summarized the important and more common problems here.

Most people take booster-dosed ritonavir without many side effects. 

Possible side effects include numbness in or around the mouth, diarrhea, nausea, liver problems, increased fat (cholesterol and triglycerides) in the blood, and possibly diabetes.  Usually you will have blood tests done in the first month to look for the beneficial effects of ritonavir and any side effects. 

Many minor side effects will either stay constant or get better with time.  It is mainly the side effects that are severe or get worse that may cause significant health risks for you.

All drugs of this type can cause or contribute to abnormal fat redistribution characterized by an enlarged belly, thinning of the face, arms, or legs.  In most cases this would be also accompanied by elevated cholesterol levels, elevated triglyceride levels, and perhaps a tendency to develop diabetes. 


This refers to the way that ritonavir affects other medications and how other medications affect ritonavir in the body.
Ritonavir interacts with many, many medications so that the other medications can be increased or decreased.  Either type of change may be dangerous to you. 

The most dangerous interactions can possibly occur with the following medications:

amiodarone, bepridil, flecainide, propafenone, quinidine
dihydroergotamine, ergonovine, ergotamine, methylergonivine
St. John's wort (hypericum perforatum)
lovastatin, simvastatin
midazolam, triazolam

If you are taking any of these medications, let your healthcare provider know immediately.

Report to you healthcare provider or go to an Emergency Room if you have severe side effects, increasing side effects, shortness of breath, uncontrollable diarrhea, fever, weakness, jaundice (eyes and skin turn yellow,) muscle pain, nausea and vomiting so that you cannot hold down your food and liquids.
You can download this handout in PDF format by clicking HERE.