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Sustiva - efavirenz

General Information This drug is almost always used as one component of a multidrug combination to suppress the human immunodeficiency (HIV) viral load.  It does not eliminate HIV; it keeps HIV suppressed so low that the virus does not do damage as it normally would.
Specifics Efavirenz has been used for several years to treat HIV.  According to many experts, efavirenz may be as potent as a protease inhibitor.  It acts by preventing the formation of HIV genetic material.  It is classified as a nonnucleoside reverse transcriptase inhibitor (NNRTI) or "non-nuke."  Efavirenz is considered to be one of the "gold standards" of HIV treatment.
Dosing Generally efavirenz is taken as 600 mg once a day just before you go to bed.  However, some people prefer to take it in the morning.  Either time is acceptable; it is important that you find the right time to suit you.

It is generally important that you take efavirenz on an empty stomach.  Food will increase the absorption of the drug and give you more side effects (see the Side Effects section below)

(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. 

It is very important that you NOT stop this medicine suddenly without substituting other medications first.  If you you do no substitute other medications for a couple of weeks, your virus might develop resistance to nevirapine and the entire class of non-nukes.  Your provider can help you with this process.

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 efavirenz 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 efavirenz without many side effects.

Possible side effects include dizziness, nightmares, nervousness, trouble sleeping, rash, nausea, headache, muscle aches, or liver problems.

Efavirenz should never be administered to pregnant women or women who can become pregnant as it can cause birth defects.

The most common side effect is central nervous system (CNS) stimulation.  Some people compare taking efavirenz to drinking several cups of coffee at one time.  Therefore it may be important for you to first take efavirenz on a weekend or non-workday so that you can gauge how well you can function before you have to work while taking the drug.  Persons who require close attention to detail in their jobs (pilots, air traffic controllers, surgeons, taxi drivers, etc.) should perhaps consider other options besides efavirenz.  The stimulation from efavirenz gradually becomes more tolerable over the first two weeks for many people.

Usually you will have blood tests done in the first month to look for the beneficial effects of efavirenz and any side effects. 

None of these ill effects are permanent.  They will go away if you are instructed to stop taking the medication and other medications are substituted.

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.

The rash that develops in some people that take efavirenz is usually a mild body rash.  Most mild rashes will stay mild or even go away.  The rashes of major concern are the ones that get worse and worse, the ones associated with fever, or the ones that are severe.  Notify your provider promptly for any rash.  Do not stop the medication unless instructed to do so by a healthcare provider familiar with efavirenz usage.

Efavirenz can also cause inflammation of the liver which is called hepatitis.  Mild hepatitis does not cause symptoms but it can be seen on liver blood tests.  Worse hepatitis causes loss of appetite, nausea and vomiting, possibly turning the skin and eyes yellow (jaundice), dark (cola-colored) urine, and light colored stools.  You should notify your healthcare provider promptly if you have any of these symptoms so that you can get liver tests done.

All drugs of this type can cause or contribute to abnormal fat redistribution characterized by 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.  Efavirenz has less of a tendency to cause these problems than perhaps the nukes (NRTIs) or protease inhibitors.

This refers to the way that efavirenz affects other medications and how other drugs affect efavirenz in the bloodstream.
Certain drugs should not be given with efavirenz:

Antihistamines: astemizole
GI motility drugs:
midazolam, triazolam
Migraine treatment or prevention:
ergot derivatives
Fungal treatment: voriconazole
Herbal therapy: St Johns wort

Efavirenz increases the metabolism (breakdown) of certain drugs so that dose adjustments, boosting, or substitutions may be necessary:

Protease inhibitors: indinavir (Crixivan), atazanavir (Reyataz), lopinavir/ritonavir (Kaletra)

Report to you healthcare provider or go to an Emergency Room if you have rash, 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.