What is this medication for?
Efavirenz is used with a combination of other anti-HIV drugs to treat the
infection caused by the human immunodeficiency virus (HIV). HIV is the virus
responsible for acquired immune deficiency syndrome (AIDS).
Efavirenz is one of a class of drugs called non-nucleoside reverse transcriptase
inhibitors (NNRTIs). Reverse transcriptase is a part of HIV required
to infect cells and make more viruses. Efavirenz prevents reverse transcriptase
from working properly.
This medication does not cure AIDS and does not prevent it from being spread
to others. It does slow further growth or reproduction of HIV when used
in combination with other drugs, and it seems to slow down the destruction of
the immune system. This may help to delay the development of problems that are
related to AIDS or HIV.
Your doctor may have suggested this medication for conditions other than those
listed here. As well, some forms of this medication may not be used for all
of the conditions discussed here. If you have not discussed this with your doctor
or are not sure why you are taking this medication, speak to your doctor. Do
not give this medication to anyone else, even if they have the same symptoms
as you do. It can be harmful for people to take this medication if their
doctor has not prescribed it. Do not stop taking this medication without
consulting your doctor.
What form(s) does this medication come in?
Sustiva® is available as:
Some medications may have other generic brands available. Always ask your doctor or pharmacist about the safety of switching between brands of the same medication.
How should I use this medication?
The recommended adult dose of efavirenz is 600 mg once daily taken
in combination with other anti-HIV (antiretroviral) drugs. Children's doses
are based on body weight.
This medication should be taken on an empty stomach and preferably at bedtime
Finish all this medication, even if you have started to feel better
Store this medication at room temperature, protect it from light and moisture,
and keep it out of the reach of children.
It is very important to take this medication on a regular basis as prescribed.
If you miss a dose, take it as soon as possible. If it is almost time for your
next dose, skip the missed dose and go back to your regular dosing schedule.
Do not take a double dose to make up for a missed one. If you forget
many doses in a row, talk to your doctor about how to resume dosing.
Many things can affect the dose of medication that a person needs, such as
body weight, other medical conditions, and other medications. If your doctor
has recommended a dose different from the ones listed here, do not change
the way that you are taking the medication without consulting your doctor.
Who should NOT take this medication?
Efavirenz should not be used by anyone who:
- is allergic to efavirenz or any ingredients of the medication
- is taking any of the following:
- astemizole or terfenadine
- benzodiazepines (e.g. midazolam, triazolam)
- cisapride
- ergot derivatives (e.g., dihydroergotamine, ergonovine, ergotamine,
methylergonovine)
There are life-threatening interactions that can occur between efavirenz
and many other medications. For your safety, if you are thinking about or
using any other medication, prescription or non-prescription, you should check
with your doctor or pharmacist first. See the "What other medications could
interact with this medication?" section for more details.