Treatments Glossary
Adherence: Often shorthand for ‘strict adherence to therapy’, meaning pills are taken exactly as prescribed—on time, every time, and observing any specific dietary requirements. Also referred to as ‘compliance’; less frequently, as ‘concordance’.
Antiretroviral: A more complex term for antiviral drugs, in this case, any drugs which are designed to inhibit the process by which HIV replicates. In some cases, the simpler term antiviral is used, and it is assumed that the virus in question is HIV. The more technical term antiretroviral refers to the fact that HIV is a retrovirus.
CCR5 Antagonists: A new drug class that target the CD4+ co-receptor called CCR5. HIV also binds to this drug class, therefore blocking the HIV from binding to these receptors on the cell. By blocking this receptor, entry of HIV into the cell is inhibited.
CD4 Cells (also: T-cells or T-helper cells): A type of blood cell involved in protecting the body against viral, fungal and protozoal infections. CD4 cells are part of the human immune response. If HIV is inside the human body, it targets, and replicates within, CD4 cells, destroying them in the process. The cells are so named because they have a particular marker, known as a CD4 receptor, on their surface. CD4 cells are sometimes called the ‘conductors’ of the immune system, since they orchestrate the responses of other cells.
Clinical Trials: Studies which test experimental medicines in humans, in order to establish that they are safe and effective. Clinical trials are staged in ‘phases’, beginning with small numbers of people, then being tested more widely as data on safety and efficacy is established.
Compliance: See adherence
Complementary Therapies: Non-traditional interventions used for health promotion and therapeutic treatment for chronic and acute illnesses, pain management, and palliative care. These non-traditional approaches include, but are not limited to, therapeutic touch, aromatherapy, acupressure, reflexology, visualization and imagery.
Drug Holiday (also Treatment Breaks): Refers to “breaks” from taking antiretroviral therapy. Should be distinguished from structured interruptions to therapy under medical conditions.
Fusion Inhibitor: A class of antiretroviral agents that binds to the envelope protein and blocks the structural changes necessary for the virus to fuse with the host CD4 cell. When the virus cannot penetrate the host cell membrane and infect the cell, HIV replication within that host cell is prevented.
HAART: Highly active antiretroviral therapy. Usually means a combination of at least three HIV antivirals from at least two of the three classes of anti-HIV drugs available: Nucleoside analogues, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. See also: HIV Drug Chart (PDF 142 KB)
Immune-based Therapies: Anti-HIV treatment which aims to improve, maintain or extend the capacities of the body’s immune system against HIV infection, or other diseases. This usually means maintaining a functional immune response in the presence of HIV, or repairing/improving immune response if HIV has already caused damage. Immune-based therapies include therapeutic vaccines and IL-2.
Integrase Inhibitors: In order for HIV to successfully take over a T-cell’s machinery so that it can produce new viruses, HIV’s RNA is converted into DNA by the reverse transcriptase enzyme (nucleotide/nucleoside reverse transcriptase inhibitors can block this process). After the “reverse transcription” of RNA into DNA is complete, HIV’s DNA must then be incorporated into the T-cell’s DNA. This is known as integration. As their name implies, integrase inhibitors work by blocking this process.
Lipoatrophy: Loss of subcutaneous fat, usually in the face and limbs. Thought to be due to some nucleoside reverse transcriptase inhibitors.
Lipodystrophy: Defective metabolism of fat. Includes fat loss (Lipoatrophy) such as wasting in the face, arms, and legs, and fat redistribution, such as fat accumulation in the upper back, breasts, and/or stomach. Thought by many to be associated with the use of protease inhibitors and some nucleoside reverse transcriptase inhibitors.
Log Changes: in viral load are often reported as logarithmic or “log changes.” This mathematical term denotes a change in value of what is being measured by a factor of 10. For example, if the baseline viral load is 40,000 copies/ml of blood, then a 1-log increase equals a 10-fold (10 times) increase, or 400,000 copies/ml of blood. A 2-log increase equals 4,000,000, or a 100-fold increase. An easy way to figure out log changes is either to drop the last “0” or add “0” to the original number.
Nucleoside Reverse Transcriptase Inhibitors (NRTIs): This class of drug (also called "nukes"), interfere with the function of reverse transcriptase, which HIV uses to replicate.
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs): A class of drug that block reverse transcriptase by binding to the reverse transcriptase enzyme. With the enzyme blocked, HIV cannot reproduce.
Opportunistic Infections: Illnesses caused by various organisms, some of which usually do not cause disease in persons with normal immune systems. Persons living with advanced HIV infection suffer opportunistic infections of the lungs, brain, eyes, and other organs. Opportunistic infections common in persons diagnosed with AIDS include Pneumocystis jiroveci (previously known as Pneumocystis carinii) pneumonia; Kaposi’s Sarcoma; cryptosporidiosis; toxoplasmosis; other parasitic, viral, and fungal infections; Opportunistic cancers can also occur.
Prophylaxis: Prescribing a drug which is known to prevent an infection from taking hold at a time when a person may not be infected, but is at risk of developing that infection or illness.
Protease Inhibitor: Antiviral drugs that act by inhibiting the virus protease enzyme, thereby preventing viral replication. Specifically, these drugs block the protease enzyme from breaking apart long strands of viral proteins to make the smaller, active HIV proteins. If the larger HIV proteins are not broken apart, they cannot assemble themselves into new functional HIV particles.
Resistance: The ability of a micro-organism like HIV to escape the control of the drugs used to fight it. In terms of HIV, this happens when the virus mutates during the replication process. Viruses like HIV, which have their genetic material encoded in RNA, lack critical genetic ‘proofreading’ mechanisms. So when new copies of HIV are created, often, minute errors in the genetic translation will occur. Over time, HIV may develop small changes to its structure which mean that anti-HIV drugs, which are designed to interfere with the virus in quite specific ways, will not be able to control it.
Resistance Test: A test which looks at the genetic structure of HIV, to determine if any mutations in the virus would make it likely to be resistant to particular antiviral drugs. Sometimes referred to as resistance assays, genotypic resistance assays, or GRAs.
Reverse Transcriptase: An enzyme which occurs in the family of viruses known as retroviruses, which includes HIV. The enzyme activates the process by which HIV changes its genetic information from RNA (in which it is encoded) into DNA, another form, which allows the genetic information of HIV to be integrated into the genetic material of a host cell (eg, a CD4 cell). Once inside this cell, HIV is able to replicate.
Reverse Transcriptase Inhibitors: A kind of drug which works to inhibit HIV by interfering with the enzyme which allows reverse transcription, described above, to occur. If reverse transcription cannot occur, or is made difficult, HIV will not be able to replicate, or its ability to do so will be diminished. There are two kinds of HIV reverse transcriptase inhibitor: the nucleosides (sometimes called nucleoside analogues), and the non-nucleosides.
Vaccine (preventative): An agent introduced into the body which mimics a particular bug or infection in order to trick the immune system into developing immunity against that bug.
Vaccine (therapeutic): An agent introduced into the body which is designed to stimulate an immune response to a virus or infection that is already in the body.
Viral load: The amount of virus present per cubic millilitre of blood. This is measured by a viral load test.
Antiretroviral: A more complex term for antiviral drugs, in this case, any drugs which are designed to inhibit the process by which HIV replicates. In some cases, the simpler term antiviral is used, and it is assumed that the virus in question is HIV. The more technical term antiretroviral refers to the fact that HIV is a retrovirus.
CCR5 Antagonists: A new drug class that target the CD4+ co-receptor called CCR5. HIV also binds to this drug class, therefore blocking the HIV from binding to these receptors on the cell. By blocking this receptor, entry of HIV into the cell is inhibited.
CD4 Cells (also: T-cells or T-helper cells): A type of blood cell involved in protecting the body against viral, fungal and protozoal infections. CD4 cells are part of the human immune response. If HIV is inside the human body, it targets, and replicates within, CD4 cells, destroying them in the process. The cells are so named because they have a particular marker, known as a CD4 receptor, on their surface. CD4 cells are sometimes called the ‘conductors’ of the immune system, since they orchestrate the responses of other cells.
Clinical Trials: Studies which test experimental medicines in humans, in order to establish that they are safe and effective. Clinical trials are staged in ‘phases’, beginning with small numbers of people, then being tested more widely as data on safety and efficacy is established.
Compliance: See adherence
Complementary Therapies: Non-traditional interventions used for health promotion and therapeutic treatment for chronic and acute illnesses, pain management, and palliative care. These non-traditional approaches include, but are not limited to, therapeutic touch, aromatherapy, acupressure, reflexology, visualization and imagery.
Drug Holiday (also Treatment Breaks): Refers to “breaks” from taking antiretroviral therapy. Should be distinguished from structured interruptions to therapy under medical conditions.
Fusion Inhibitor: A class of antiretroviral agents that binds to the envelope protein and blocks the structural changes necessary for the virus to fuse with the host CD4 cell. When the virus cannot penetrate the host cell membrane and infect the cell, HIV replication within that host cell is prevented.
HAART: Highly active antiretroviral therapy. Usually means a combination of at least three HIV antivirals from at least two of the three classes of anti-HIV drugs available: Nucleoside analogues, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. See also: HIV Drug Chart (PDF 142 KB)
Immune-based Therapies: Anti-HIV treatment which aims to improve, maintain or extend the capacities of the body’s immune system against HIV infection, or other diseases. This usually means maintaining a functional immune response in the presence of HIV, or repairing/improving immune response if HIV has already caused damage. Immune-based therapies include therapeutic vaccines and IL-2.
Integrase Inhibitors: In order for HIV to successfully take over a T-cell’s machinery so that it can produce new viruses, HIV’s RNA is converted into DNA by the reverse transcriptase enzyme (nucleotide/nucleoside reverse transcriptase inhibitors can block this process). After the “reverse transcription” of RNA into DNA is complete, HIV’s DNA must then be incorporated into the T-cell’s DNA. This is known as integration. As their name implies, integrase inhibitors work by blocking this process.
Lipoatrophy: Loss of subcutaneous fat, usually in the face and limbs. Thought to be due to some nucleoside reverse transcriptase inhibitors.
Lipodystrophy: Defective metabolism of fat. Includes fat loss (Lipoatrophy) such as wasting in the face, arms, and legs, and fat redistribution, such as fat accumulation in the upper back, breasts, and/or stomach. Thought by many to be associated with the use of protease inhibitors and some nucleoside reverse transcriptase inhibitors.
Log Changes: in viral load are often reported as logarithmic or “log changes.” This mathematical term denotes a change in value of what is being measured by a factor of 10. For example, if the baseline viral load is 40,000 copies/ml of blood, then a 1-log increase equals a 10-fold (10 times) increase, or 400,000 copies/ml of blood. A 2-log increase equals 4,000,000, or a 100-fold increase. An easy way to figure out log changes is either to drop the last “0” or add “0” to the original number.
Nucleoside Reverse Transcriptase Inhibitors (NRTIs): This class of drug (also called "nukes"), interfere with the function of reverse transcriptase, which HIV uses to replicate.
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs): A class of drug that block reverse transcriptase by binding to the reverse transcriptase enzyme. With the enzyme blocked, HIV cannot reproduce.
Opportunistic Infections: Illnesses caused by various organisms, some of which usually do not cause disease in persons with normal immune systems. Persons living with advanced HIV infection suffer opportunistic infections of the lungs, brain, eyes, and other organs. Opportunistic infections common in persons diagnosed with AIDS include Pneumocystis jiroveci (previously known as Pneumocystis carinii) pneumonia; Kaposi’s Sarcoma; cryptosporidiosis; toxoplasmosis; other parasitic, viral, and fungal infections; Opportunistic cancers can also occur.
Prophylaxis: Prescribing a drug which is known to prevent an infection from taking hold at a time when a person may not be infected, but is at risk of developing that infection or illness.
Protease Inhibitor: Antiviral drugs that act by inhibiting the virus protease enzyme, thereby preventing viral replication. Specifically, these drugs block the protease enzyme from breaking apart long strands of viral proteins to make the smaller, active HIV proteins. If the larger HIV proteins are not broken apart, they cannot assemble themselves into new functional HIV particles.
Resistance: The ability of a micro-organism like HIV to escape the control of the drugs used to fight it. In terms of HIV, this happens when the virus mutates during the replication process. Viruses like HIV, which have their genetic material encoded in RNA, lack critical genetic ‘proofreading’ mechanisms. So when new copies of HIV are created, often, minute errors in the genetic translation will occur. Over time, HIV may develop small changes to its structure which mean that anti-HIV drugs, which are designed to interfere with the virus in quite specific ways, will not be able to control it.
Resistance Test: A test which looks at the genetic structure of HIV, to determine if any mutations in the virus would make it likely to be resistant to particular antiviral drugs. Sometimes referred to as resistance assays, genotypic resistance assays, or GRAs.
Reverse Transcriptase: An enzyme which occurs in the family of viruses known as retroviruses, which includes HIV. The enzyme activates the process by which HIV changes its genetic information from RNA (in which it is encoded) into DNA, another form, which allows the genetic information of HIV to be integrated into the genetic material of a host cell (eg, a CD4 cell). Once inside this cell, HIV is able to replicate.
Reverse Transcriptase Inhibitors: A kind of drug which works to inhibit HIV by interfering with the enzyme which allows reverse transcription, described above, to occur. If reverse transcription cannot occur, or is made difficult, HIV will not be able to replicate, or its ability to do so will be diminished. There are two kinds of HIV reverse transcriptase inhibitor: the nucleosides (sometimes called nucleoside analogues), and the non-nucleosides.
Vaccine (preventative): An agent introduced into the body which mimics a particular bug or infection in order to trick the immune system into developing immunity against that bug.
Vaccine (therapeutic): An agent introduced into the body which is designed to stimulate an immune response to a virus or infection that is already in the body.
Viral load: The amount of virus present per cubic millilitre of blood. This is measured by a viral load test.
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