- What are NNRTIs in antiretroviral therapy for HIV infection?
- What is antiretroviral therapy for HIV infection?
- What is HIV infection?
- How do NNRTIs work?
- What is the difference between nucleoside and non-nucleoside reverse transcriptase inhibitors?
- What are the major side effects of NNRTIs?
- What are the FDA-approved NNRTIs and their side effects?
What are NNRTIs in antiretroviral therapy for HIV infection?
Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are one of the classes of drugs that form part of the antiretroviral therapy (ART) for human immunodeficiency virus (HIV) infection. The first NNRTI drug was introduced in 1996, and since then this drug class has been an integral part of HIV treatment.
What is antiretroviral therapy for HIV infection?
Antiretroviral therapy is a treatment regimen for HIV infection, with a combination of three or more drug classes that stop virus replication in different ways. An NNRTI drug is usually one of the drugs used in the combination when antiretroviral therapy is first initiated after diagnosis of HIV infection.
What is HIV infection?
HIV infection is caused by a virus that infects and weakens the human immune system. HIV specifically targets the T-cell, which is a type of lymphocyte that develops in the thymus gland and is an integral part of the immune system. The virus enters the T-cell and uses its cell machinery to replicate itself, destroying the host cell in the process.
Untreated HIV can progress to acquired immune deficiency syndrome (AIDS), a late stage of HIV infection when the body’s immunity is so compromised it cannot fight infections effectively. HIV infection has no cure, and the patient must be on a lifelong regimen of antiretroviral therapy to manage the infection and prevent its transmission.
How do NNRTIs work?
HIV is a minute virus particle with a single strand of genetic matter known as RNA. In its RNA form, the virus cannot enter the nucleus of the T-cell or use the cell machinery for its replication. The virus releases and uses a special enzyme known as reverse transcriptase to convert its RNA into DNA that can enter the nucleus.
The NNRTI drug binds to the reverse transcriptase enzyme, altering its structure and inhibiting its function in the transcription of RNA into DNA. NNRTIs are effective in controlling HIV infection, particularly the newer formulations, which are able to bind with even resistant viral mutations to some extent.
What is the difference between nucleoside and non-nucleoside reverse transcriptase inhibitors?
Both nucleoside and non-nucleoside reverse transcriptase inhibitors work at the same stage of the viral replication cycle, when the viral RNA converts itself into DNA using reverse transcriptase enzyme.
The nucleoside transcriptase inhibitors (NRTIs), have a nucleoside that is structurally similar to the T-cell DNA’s nucleoside. Mimicking the T-cell enables the NRTIs to integrate with the T-cell DNA and stop the production of viral DNA proteins.
The non-nucleoside transcriptase inhibitors do not get into the cell nucleus or interfere with the DNA. NNRTIs bind directly to the HIV’s reverse transcriptase enzyme and inhibit its activity.

SLIDESHOW
A Timeline of the HIV/AIDS Pandemic See SlideshowWhat are the major side effects of NNRTIs?
NNRTIs have a relatively higher potential for drug-on-drug interactions in patients taking other medications for co-existing conditions. Major side effects of NNRTIs include:
Most of the side effects resolve after a few weeks of therapy. Gradual increase of dosage helps in reducing some of the side effects.
What are the FDA-approved NNRTIs and their side effects?
Following are the FDA-approved individual NNRTIs that are currently part of antiretroviral therapy for HIV infection; common side effects are listed.
Delavirdine (Rescriptor)
Available as tablets, but not used as a part of initial therapy, and rarely used even as second-line treatment because of its low efficacy in comparison with other NNRTIs.
Side effects include:
Efavirenz (Sustiva)
Available as tablets and capsules, taken on empty stomach to reduce the intensity of side effects.
Side effects include:
- Rash
- Central nervous system effects such as
- Hyperlipidemia (high levels of blood fats)
Etravirine (Intelence)
Available as tablets and approved only for antiretroviral treatment–experienced patients with drug resistance.
Side effects include:
- Rash
- Nausea
Nevirapine (Viramune, Viramune XR)
Available as tablets and suspension.
Side effects include:
- Rash
- Hepatitis
Rilpivirine (Edurant)
Available as tablets.
Side effects include:
Doravirine (Pifeltro)
Available as tablets. May lose efficacy if given with certain antibiotic drugs that boost a particular enzyme in the body, known as CYP3A4, and lead to HIV drug resistance.
Side effects include:
- Immune reconstitution syndrome: Development of inflammatory symptoms caused by the response of the immune system that has recovered with antiretroviral therapy, which starts attacking other pre-existing, latent bacterial or viral infections. These symptoms usually resolve in a few weeks:
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How Long Can You Live with HIV?
HIV stands for human immunodeficiency virus. If someone has HIV it means that they have been diagnosed with the HIV infection. AIDS (acquired immune deficiency syndrome); however, is the most advanced or final stage of the HIV infection. In the case of an untreated HIV infection, the overall mortality rate is more than 90%. The average time from infection to death is eight to ten years.
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Human Immunodeficiency Virus (HIV)
HIV (human immunodeficiency virus) infection left untreated causes AIDS (acquired immunodeficiency syndrome). The human immunodeficiency virus (HIV) is a type of virus called a retrovirus, which can infect humans when it comes in contact with tissues that line the vagina, anal area, mouth, or eyes, or through a break in the skin. HIV infection is generally a slowly progressive disease in which the virus is present throughout the body at all stages of the disease. Three stages of HIV infection have been described. The initial stage of infection (primary infection), which occurs within weeks of acquiring the virus, often is characterized by the flu- or mono-like illness that generally resolves within weeks. The stage of chronic asymptomatic infection (meaning a long duration of infection without symptoms) lasts an average of eight to 10 years without treatment. The stage of symptomatic infection, in which the body's immune (or defense) system has been suppressed and complications have developed, is called the acquired immunodeficiency syndrome (AIDS). The symptoms are caused by the complications of AIDS, which include one or more unusual infections or cancers, severe loss of weight, and intellectual deterioration (called dementia). When HIV grows (that is, by reproducing itself), it acquires the ability to change (mutate) its own structure. These mutations enable the virus to become resistant to previously effective drug therapy. The goals of drug therapy are to prevent damage to the immune system by the HIV virus and to halt or delay the progress of the infection to symptomatic disease. Therapy for HIV includes combinations of drugs that decrease the growth of the virus to such an extent that the treatment prevents or markedly delays the development of viral resistance to the drugs. The best combination of drugs for HIV are those that effectively suppress viral replication in the blood and also are well tolerated and simple to take so that people can take the medications consistently without missing doses.
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What Is the Difference Between HIV-1 and HIV-2?
There are two main types of the human immunodeficiency virus (HIV), HIV-1 and HIV-2. HIV-1 is the most common type of HIV and accounts for 95% of all infections, whereas HIV-2 is relatively uncommon and less infectious. HIV-2 is mainly concentrated in West Africa, is less deadly and progresses more slowly.
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How Long Does It Take to See Signs of HIV?
The signs and symptoms of HIV may first appear within two to four weeks of infection. The stage in which the symptoms appear is called the stage of acute HIV infection. The symptoms appear due to the resistance or fight of the immune system against HIV. Early diagnosis and treatment of HIV gets the best results.
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What Are the Four Stages of HIV?
The World Health Organization (WHO) classifies human immunodeficiency virus (HIV) into four stages. Stage 1 (HIV infection): The CD4+ cell count is at least 500 cells per microliter. Stage 2 (HIV infection): The CD4+ cell count is 350 to 499. Stage 3 (advanced HIV disease or AHD): The CD4+ cell count is 200 to 349. Stage 4 (Acquired immunodeficiency syndrome [AIDS]): The CD4+ cell count is less than 200.
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How Long Does It Take to Notice Signs of HIV?
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Can HIV be Cured Naturally?
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How Do You Feel When You Have HIV?
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What Is Usually the First Sign of HIV?
Human immunodeficiency virus (HIV) attacks the cells of the immune system, leading to AIDS and death if left untreated. The first signs of the human immunodeficiency virus infection are flu-like symptoms, which mainly start around two to four weeks after getting HIV. This stage is known as acute HIV infection.
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HIV/AIDS Facts: What Is HIV?
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What Are the Side Effects of HIV Medications?
It’s important to know the potential side effects of all the drugs you take to control your HIV infection, as well as potential drug interactions. All of the NNRTIs (nonnucleoside analogue reverse transcriptase inhibitors), for example, are associated with important drug-drug interactions so they must be used with caution in patients on other medications. Learn more about the side effects of the drugs in standard treatment regimens.
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When should you start HIV medication?
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SLIDESHOW
A Timeline of the HIV/AIDS Pandemic See SlideshowTreatment & Diagnosis
- HIV-AIDS FAQs
- HIV Treatment, Medications, and Prevention
- Retrovirus & Opportunistic Infections Part II
- Retroviruses and Opportunistic Infections Conf. 2/2006
- HIV: Two Patients Face The Diagnosis
- HIV Treatment - To Interrupt or Not
- Unprotected Sex Between HIV-Infected Partners: What's the Harm?
- HIV Transmission and Progression to AIDS Continues
- Physical and Biochemical Changes in HIV Disease
- Babies On The Breast Of HIV Moms
- Can HIV Cause Kaposi's Sarcoma?
- Do You Need Antiretroviral Therapy for HIV with No Symptoms?
- Does HIV Cause Colorectal Cancer?
- Does Anti-Retroviral Therapy for HIV Cause Diabetes?
- How Long Should You Wait to Get an HIV Test?
- What Liver Problems Does HIV Cause?
- Does Circumcision Prevent HIV and AIDS?
- HIV Infection Facts, History, Causes, and Risk Factors
- HIV Tests, Symptoms, Signs, and Stages of Infection
- Baby "Cured" of HIV Infection
Medications & Supplements
- delavirdine 100 mg dispersible tablet - oral, Rescriptor
- nevirapine - oral, Viramune
- delavirdine 200 mg tablet - oral, Rescriptor
- efavirenz - oral, Sustiva
- How Effective Is ART for HIV Infection?
- Symtuza (darunavir, cobicistat, emtricitabine, and tenofovir alafenamide)
- Genvoya
- What Are NRTIs in Antiretroviral Therapy For HIV Infection?
- Valcyte (valganciclovir hydrochloride)
- efavirenz (Sustiva)
- Dovato (dolutegravir and lamivudine)
- Prezcobix (darunavir and cobicistat)
- Trogarzo (ibalizumab-uiyk)
- delavirdine (Rescriptor)
- Stribild (elvitegravir, cobicistat, emtricitabine, tenofovir disoproxil fumarate)
- dolutegravir
- nevirapine (Viramune, Viramune XR)
- Etravirine (Intelence)
- Prezista (darunavir)
- Triumeq (abacavir, dolutegravir, and lamivudine)
- Mycobutin (rifabutin)
- Pifeltro (doravirine)
- Epzicom (abacavir sulfate and lamivudine)
- Side Effects of Trizivir (abacavir, lamivudine, zidovudine)

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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HIV stands for human immunodeficiency virus. If someone has HIV it means that they have been diagnosed with the HIV infection. AIDS (acquired immune deficiency syndrome); however, is the most advanced or final stage of the HIV infection. In the case of an untreated HIV infection, the overall mortality rate is more than 90%. The average time from infection to death is eight to ten years.How Long Does It Take to Notice Signs of HIV?
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There are two main types of the human immunodeficiency virus (HIV), HIV-1 and HIV-2. HIV-1 is the most common type of HIV and accounts for 95% of all infections, whereas HIV-2 is relatively uncommon and less infectious. HIV-2 is mainly concentrated in West Africa, is less deadly and progresses more slowly.What Is Usually the First Sign of HIV?
Human immunodeficiency virus (HIV) attacks the cells of the immune system, leading to AIDS and death if left untreated. The first signs of the human immunodeficiency virus infection are flu-like symptoms, which mainly start around two to four weeks after getting HIV. This stage is known as acute HIV infection.