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Agenerase - amprenavir

General Information Amprenavir is almost always used as one component of a multidrug combination to suppress the human immunodeficiency (HIV) viral load.
Specifics Amprenavir is a well-respected and effective antiviral drug against HIV.

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

Dosing Generally amprenavir is taken as six of the 150 mg gel caps twice a day with or without food.  At this dosage of amprenavir, the amprenavir is taken with 100 mg of ritonavir (Norvir) twice a day.  As discussed on the ritonavir page on this site, ritonavir is used to increase the levels of amprenavir in the bloodstream so that the drug is more effective and so that dosing frequency and the expense of the medication are minimized.  This is called boosting.

Sometimes amprenavir is taken as eight (8) of the 150 mg capsules once a day with two of the 100 mg ritonavir (Norvir) gel caps as a single dose each day.

Also in some cases amprenavir is given (without ritonavir) as eight (8) of the 150 mg capsules twice a day.

There is a liquid form available but this should not be used in children younger than 4 years of age.

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

It is very important that you do not alter the dosing of amprenavir or ritonavir without advice from 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.

You should commit yourself to taking every dose of each of your antiviral medications each day, or you should decide to not take the medications at all.  Taking only some of the medications or missing doses actually may do more harm than good.  The author of this information page refers to this rule as the "all or none" rule.

Possible Side Effects
The package insert for most drugs including amprenavir 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 amprenavir without many side effects. 

Possible side effects include stomach upset, diarrhea, nausea, liver problems, increased fat (cholesterol and triglycerides) in the blood, skin rash, and possibly diabetes.  Usually you will have blood tests done in the first month to look for the beneficial effects of amprenavir and any side effects. 

If you are allergic to sulfa drugs (for example Bactrim, Septra, sulfadiazine, sulfamethoxazole) you may be allergic to amprenavir.

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 and/or 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.   Amprenavir may have less effect on these problems than other protease inhibitors.

This refers to the way that amprenavir affects other medications
Many other medications may not mix well with amprenavir (with or without ritonaivr) including antidepressants, anticholesterol drugs, drugs for erection problems, blood thinners, herbal products, certain protease inhibitors (lopinavir/ritonair, Kaletra) and antibiotics.  Make sure your healthcare providers knows all the medications you are taking including any herbal and over the counter medications.
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, skin rash, nausea and vomiting so that you cannot hold down your food and liquids.
You can download this handout in PDF format by clicking HERE.