efavirenz, Sustiva

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

HIV/AIDS Myths and Facts

What is efavirenz, and how does it work (mechanism of action)?

Efavirenz is an oral medication that is used for the treatment of infections with the human immunodeficiency virus (HIV). Efavirenz is in a class of drugs called reverse transcriptase inhibitors which also includes zalcitabine (Hivid), zidovudine (Retrovir), didanosine (Videx), and lamivudine (Epivir). It is in a subclass of reverse transcriptase inhibitors referred to as non-nucleoside reverse transcriptase inhibitors that includes nevirapine (Viramune), and delavirdine (Rescriptor). During infection with HIV, the HIV virus multiplies within the body's cells. The newly-formed viruses then are released from the cells and spread throughout the body where they infect other cells. In this manner, the infection continually spreads to new, uninfected cells that the body is continually producing, and HIV infection is perpetuated. When producing new viruses, the HIV virus must manufacture new DNA for each virus. Reverse transcriptase is the enzyme that the virus uses to form new DNA. Efavirenz directly inhibits the activity of reverse transcriptase and blocks the production of DNA and new viruses. Efavirenz does not kill existing HIV virus and it is not a cure for HIV. Efavirenz was approved by the FDA in 1998.

What brand names are available for efavirenz?

Sustiva

Is efavirenz available as a generic drug?

GENERIC AVAILABLE: No

Do I need a prescription for efavirenz?

Yes

What are the side effects of efavirenz?

The most common side effects of efavirenz are:

Other side effects include

Serious psychiatric adverse effects such as depression, suicidal thoughts, manic reactions, and aggressive behavior have been reported in patients taking efavirenz. Immune reconstitution syndrome which is an inflammatory response to infection may occur in patients treated with combination antiretroviral therapy.

Quick GuideHIV AIDS Facts: Symptoms and Treatments

HIV AIDS Facts: Symptoms and Treatments

What is the dosage for efavirenz?

The recommended dose for adults is 600 mg daily. Efavirenz must be administered in combination with other anti-HIV drugs because the HIV virus quickly becomes resistant to treatment when efavirenz is used alone. Efavirenz should be administered on an empty stomach to improve absorption, preferably at bedtime.

Which drugs or supplements interact with efavirenz?

Efavirenz has many drug interactions because many drugs affect its breakdown and elimination by the liver. Efavirenz also affects the breakdown of other drugs by the liver. The following are some examples of drugs that interact with efavirenz.

Triazolam (Halcion), midazolam (Versed), bepridil (Vascor), pimozide (Orap), and ergot derivatives (for example, ergotamine, dihydroergotamine) should not be combined with efavirenz because efavirenz increases blood levels of these drugs, potentially causing serious adverse effects. St. John's wort should not be combined with efavirenze because it reduces blood levels of efavirenz, leading to possible loss of effectiveness.

Efavirenz increases the breakdown of saquinavir (Invirase) and indinavir (Crixivan). This leads to lower drug concentrations in the body and reduces the effect of saquinavir and indinavir.

Efavirenz increases the concentration of ritonavir (Norvir) while Ritonavir increases the concentration of efavirenz. Increased drug concentrations may result in more frequent or more serious side effects.

Is efavirenz safe to take if I'm pregnant or breastfeeding?

There are no adequate studies in pregnant women. Data from an antiretroviral pregnancy registry revealed birth defects in 17 of 604 live births in women who took efavirenz during the first trimester.

It is not known whether efavirenz is excreted in human breast milk. HIV-infected mothers should not breastfeed because of the risk of transmitting HIV to an infant that is not infected.

What else should I know about efavirenz?

What preparations of efavirenz are available?

Capsules: 50 and 200 mg. Tablet: 600 mg.

How should I keep efavirenz stored?

Efavirenz should be stored at room temperature, 15 C to 30 C (59 F to 86 F).

Reference: FDA Prescribing Information

Quick GuideHIV AIDS Facts: Symptoms and Treatments

HIV AIDS Facts: Symptoms and Treatments

Summary

Efavirenz (Sustiva) is a drug prescribed to treat infections with the human immunodeficiency virus (HIV). Side effects, drug interactions, warnings and precautions, and pregnancy safety should be reviewed prior to taking this drug.

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Prevention & Wellness

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See more info: efavirenz on RxList
Reviewed on 6/17/2015
References
Reference: FDA Prescribing Information

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