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Reyataz - atazanavir

General Information This drug is almost always used as one component of a multidrug combination to suppress the human immunodeficiency (HIV) viral load.
Specifics Atazanavir is one of the newest antiviral drugs against HIV, but it is rapidly establishing itself as a potent, convenient, and well-tolerated option.

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

Dosing Generally atazanavir is taken as two of the 200 mg capsules once a day with food.  However, very frequently atazanavir is taken with 100 mg of ritonavir (Norvir) and the dose is changed to one 300 mg capsule or two of the 150 mg capsules of atazanavir once a day.

This combination of ritonavir and atazanavir is termed "boosted atazanavir" because ritonavir increases the levels of atazanavir in the bloodstream.  This boosted dosing is used when atazanavir is combined with tenofovir (Viread) and/or efavirenz (Sustiva).  Even when tenofovir or efavirenz are not used, many healthcare providers will boost the atazanavir with ritonavir.

Atazanavir requires normal levels of stomach acid for absorption into your bloodstream.  Avoid taking any medications that lower stomach acid such as histamine-2 blockers (Zantac, Pepcid, Tagamet, etc.), proton pump inhibitors (Nexium, Prevacid, Prilosec) or antacids if it is safe and tolerated for you to do so.  If you must take antacids space then at least 1 hour before dosing with atazanavir or at least 2 hours after dosing with atazanavir.  If you must use a histamine-2 blocker, take it 12 hours apart from your atazanavir.  You must NOT take any of the proton pump inhibitors at all.  See the Interactions section below.

(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. 

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 atazanavir 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 atazanavir without many side effects. 

Possible side effects include stomach upset, diarrhea, nausea, trouble sleeping, liver problems, increased fat (cholesterol and triglycerides) in the blood, turning yellow with jaundice, and possibly diabetes.  Usually you will have blood tests done in the first month to look for the beneficial effects of atazanavir 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.

Far and away the most common side effect of atazanavir is elevated blood bilirubin levels.  Bilirubin is a pigment that the liver secretes to help it digest food.  When bilirubin is elevated in the blood due to atazanavir, it can be seen early on and in milder forms only in blood tests.  If the bilirubin goes higher, you may notice yellowing of your eyes and/or your skin.  While annoying, this condition is not dangerous or particularly harmful to the liver.

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.   Atazanavir seems to have less effect on these problems than other protease inhibitors.

This refers to the way that atazanavir affects other medications and how other medications affect atazanavir.
Many other drugs have interactions with atazanavir that may be helpful, harmful, or even deadly.

Make sure that you tell your healthcare provider about all of your medications including over-the-counter ones. 

Medications which lower stomach acid especially drugs known as proton pump inhibitors (PPI) such as omeprazole (Prilosec), lansoprazole (Prevacid), esomeprazole (Nexium) should NOT be taken with atazanavir as they lower the amount of atazanavir to dangerously low levels.  Drugs such as ranitidine (Zantac) and famotidine (Pepcid) should also be taken cautiously and only after consultation with your healthcare provider.

Some medications should NOT be taken at all with atazanavir:

Proton pump inhibitors to reduce stomach acidity: omeprazole (Prilosec), lansoprazole (Prevacid, Prevacid NapraPAC, Pevacid SoluTab), esomeprazole (Nexium),
Drugs to regulate heart rhythm: irinotecan (Camptosar)
Ergot derivatives for migraine headaches: dihydroergotamine (D.H.E. 45), ergonovine, ergotamine, methylergonovine (Methergine)
Drugs to treat mental health problems (Tourette's syndrome): pimozide (Orap)
Sedatives/sleeping pills: midazolam (Versed), triazolam (Halcion)
Statins (drugs to decrease cholesterol) other than atorvastatin (Lipitor), pravastatin (Pravachol)
St John's wort
Tuberculosis treatment: rifampin (Rifadin, Rimactane, Rifamate)
Drugs to prevent seizures: carbemazepine (Tegretol), phenobarbital
Calcium channel blocker for heart or blood pressure control: bepridil

Certain drugs should be used only very cautiously with atazanavir:

Histamine-2 receptor blockers to reduce stomach acid: ranitidine (Zantac), cimetidine (Tagamet), famotidine (Pepcid)
Drugs to prevent seizures: phenytoin (Dilantin)
All erectile dysfunction drugs: sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra)
Drugs to prevent rejection of transplanted organs or bone marrow: cyclosporine (Neoral, Sandimmune), tacrolimus (FK506, Prograf), sirolimus (Rapamune)
Drugs to treat mycobacteria or TB-like infections: rifabutin (Mycobutin)
Oral contraceptive pills (another form of contraception should be used in addition)
Antibiotics: clarithromycin (Biaxin)
Calcium channel blockers for heart or blood pressure control: diltiazem and others
Antacids: Maalox, Mylanta, Amphogel, Tums, Rolaids, and many others

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.