How Antiretroviral Therapy Works
HIV causes disease by depleting immune cells, called CD4 T-cells, that the body needs for an effective immune response. As their numbers are depleted, the body’s ability to fight disease diminishes, leaving it vulnerable to an ever-widening range of opportunistic infections.
In order for HIV to replicate, it must go through various stages of its life cycle:
Once new viral particles are released, the cycle starts anew.
Antiretroviral drugs work by blocking different stages of this cycle. When used in combination, they function as a biochemical tag teamâone that is able to suppress the multitude of viral mutations that can exist within a single HIV population.
If one antiretroviral drug is unable to suppress a certain mutation, the other one or two drugs usually can by blocking a different stage of the cycle.
To ensure you receive the right combination of drugs, doctors will perform genetic resistance testing and other tests to establish the characteristics of your virus and the number and types of resistant mutations you have. By doing so, the doctor can tailor your treatment by picking the drugs most able to suppress those mutations.
How Well Does The Use Of Hiv Treatment To Maintain An Undetectable Viral Load Prevent The Sexual Transmission Of Hiv
Research conducted in serodiscordant couples shows that consistent and correct use of HIV treatment to maintain an undetectable viral load is a highly effective strategy to prevent sexual HIV transmission for both heterosexual and same-sex male couples. Evidence from this research shows that when people are on successful treatment and engaged in care they do not transmit HIV through sex.
Results from a large two-phase observational study known as PARTNER/PARTNER2 showed that treatment and an undetectable viral load prevents sexual HIV transmission in both heterosexual and same-sex male couples in the absence of other forms of HIV prevention . The first phase of the study included heterosexual and same-sex male couples, and the second phase continued with only same-sex male couples. In this study there were many unprotected sex acts when the HIV-positive partners viral load was undetectable approximately 36,000 among heterosexual couples and 76,000 among same-sex male couples enrolled in the study. By the end of the study, there were no HIV transmissions between couples in the study when the HIV-positive partner was on treatment and had an undetectable viral load. However, 16 new HIV infections were transmitted from a sex partner outside of the relationship.
Hit Hard And Hit Quickly
For an antiviral to be effective, it not only has to target a virus while leaving healthy cells alone, but it must also be very potent, capable of quickly knocking out pretty much;an entire viral infection.
That’s because viruses replicate in enormous numbers, sometimes churning out millions of new viruses in a matter of hours.
Some, such as RNA viruses, don’t have any genetic “proofreading”, which means their genetic code can change or mutate very quickly, Dr Moseley says.
“So we can make an antiviral against a virus, but then typically, the virus can develop resistance very rapidly.”
Many viruses are good at hiding from the body’s immune system too.
Dr Moseley’s lab is investigating how viruses modify their host cell to become efficient virus factories, and the tricks viruses use to shut down the host cell’s immune defences so they can better replicate and spread.
Then there are the genome lurkers; retroviruses such as HIV and herpes simplex virus that hide in our DNA.
Drugs can’t yet scrub HIV DNA out of our own, but Professor Lewin’s lab at the Doherty Institute is looking for a cure to “wake up”;the virus from its latent stage and get rid of it for good.
The one big disease that can be cured with direct-acting antivirals is hepatitis C.
Like HIV, it was discovered in the 1980s, but it has no latent form.
Professor Schinazi and his fellow researchers developed treatments which have a near 100 per cent cure rate.
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“You can cut out a significant amount of the research and development and go relatively rapidly into trials for efficacy and safety,”;Dr Moseley says.
” can still take a couple of years at least.
“So it’s not rapid, but it’s rapid compared with the full drug development pipeline.”
For example, remdesivir;was originally developed for hepatitis C, then used in Ebola.
But it has a major drawback. A course of remdesivir typically involves daily intravenous injections over a week or more, Professor Schinazi says.
An ideal COVID-19 antiviral would be one that’s cheap and easy to make, and given as a tablet to anyone as soon as they tested positive or became symptomatic, so it can crush the virus before it has a chance to kick;off an immune overreaction.
Professor Schinazi’s lab at Emory is still investigating new, better antivirals to treat diseases such as HIV, but he’s also turned attention to COVID-19.
We’re making headway, but not as fast as we would like,”;he says.
I hope we’ll have antivirals soon, in the next year or less.
“And I hope that we will be better prepared for the next pandemic, because we’ve got to learn a lot from this one.”
Whats The Difference Between Antibiotics And Antivirals
Antibiotics help the immune system fight off bacterial infections. Bacteria typically reproduce outside of cells, making it easier for medicines to target them. An antibiotic can usually treat many different types of bacterial infections. But the drugs do not affect viruses.
Each antiviral only works against a specific virus. Because viruses inside cells are harder to target, antiviral drugs are more challenging to develop. There are more viruses than antiviral drugs to treat them.
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Side Effects Of Antiretroviral Drugs
Side effects of combinations of antiretroviral drugs may be unpleasant and serious. However, doctors can prevent many serious problems by regularly examining the person and doing blood tests. The blood tests can detect side effects before they become serious and enable doctors to change antiretroviral drugs when needed. For most people, doctors can find a combination of drugs with minimal side effects.
Metabolism of fats may be disturbed, probably primarily by protease inhibitors. The following may result:
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Fat accumulates in the abdomen and breasts of women , and it is lost from the face, arms, and legs.
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The body become less sensitive to insulin’s effects
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Blood levels of cholesterol and triglycerides are increased.
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St. John’s wort St. Johns Wort The reddish substance in the plants flowers contains numerous biologically active compounds, including hypericin and hyperforin. People take St…. read more causes the body to process protease inhibitors and non-nucleoside reverse transcriptase inhibitors more quickly and thus makes them less effective.
What Can Be Done For People Who Have Severe Immunosuppression
Although one goal of antiviral therapy is to prevent the development of immune suppression, some individuals are already immunosuppressed when they first seek medical care. In addition, others may progress to that stage as a result of resistance to antiviral drugs. Every effort must be made to optimize antiviral therapy in these patients. In addition, certain specific antibiotics should be initiated, depending on the number of CD4 cells, to prevent the complications that are associated with HIV immunosuppression. Guidelines for the prevention of opportunistic infections can be found at http://www.aidsinfo.nih.gov
In summary, patients with a CD4 cell count of less than 200 cells/mm3 should receive preventative treatment against Pneumocystis jiroveci with trimethoprim/sulfamethoxazole , given once daily or three times weekly. If the patients are intolerant to that drug, they can be treated with an alternative drug such as dapsone or atovaquone . Those patients having CD4 cell count of less than 100 cells/mm3 who also have evidence of past infection with Toxoplasma gondii, which is usually determined by the presence of toxoplasma antibodies in the blood, should receive trimethoprim/sulfamethoxazole. Toxoplasmosis is an opportunistic parasitic disease that affects the brain and liver. If a person is using dapsone to prevent Pneumocystis jiroveci, pyrimethamine and leucovorin can be added once a week to dapsone to prevent toxoplasmosis.
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Taking Antiretroviral Treatment With Other Medicines
If you are taking other medications or drugs including: treatments for other health conditions; contraception ; hormonal therapies; or use psychoactive drugs, its important that your doctor knows about this. Different drugs can interact, changing the way that they work. This may mean that a drug becomes too strong or that a drug becomes too weak, so that it can no longer control your HIV, prevent pregnancy or treat another health condition. Discuss the medication you take with your healthcare workers so they make sure that the combination is safe and will work well for you.
Mode Of Action Integrase Inhibitor
Integrase Inhibitors are a new class of drugs which target the HIV enzyme integrase. This is the enzyme responsible for the integration of viral genetic material into human DNA, a crucial step in the replication cycle of HIV.
Raltegravir is the first medicine to be approved in the class of antiretroviral drugs called integrase inhibitors. It was approved by the U.S. Food and Drug Administration in October 2007. Raltegravir is approved for use in combination with other antiretroviral agents for the treatment of HIV-1 infection in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents. It is not yet approved for people with drug-sensitive HIV strains, such as those starting antiretroviral therapy for the first time and has not been approved for use in children.
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How Long Do You Need To Take Antiviral Drugs
Treatment length varies depending on the antiviral drug and viral infection. You may need one dose of an IV drug or a week of oral medicine.
People who have chronic ailments like HIV may take daily antivirals for life. This drug regimen keeps the virus from becoming active. It can prevent the virus from infecting others.
Starting Art During Pregnancy Or Breastfeeding
If you’re pregnant or breastfeeding it’s particularly important that you start treatment straight away. This is because ART prevents HIV from being passed on to your baby.
ART is safe to take during pregnancy and breastfeeding, and will keep you and your baby healthy. Talk to your healthcare worker about which combination of antiretroviral drugs is best for you and feel free to ask them any other questions or concerns that you have. They are there to help.
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What Should People Know About Taking Hiv Medicines
Taking HIV medicines keeps people with HIV healthy and prevents HIV transmission. Taking HIV medicines every day and exactly as prescribed also reduces the risk of drug resistance.
But sometimes HIV medicines can cause side effects. Most side effects from HIV medicines are manageable, but a few can be serious. Overall, the benefits of HIV medicines far outweigh the risk of side effects. In addition, newer HIV medicines cause fewer side effects than medicines used in the past. As HIV treatment continues to improve, people are less likely to have side effects from their HIV medicines.
HIV medicines can interact with other HIV medicines in an HIV regimen or with other medicines a person is taking. Health care providers carefully consider potential drug interactions before recommending an HIV regimen.
What Are The Side Effects Of Antiretrovirals
People who use antiretrovirals can have side effects such as high cholesterol, high blood sugar, liver or kidney damage, bleeding, anaemia, sleep problems, nausea, loss of appetite and rash.
Not everyone has side effects from their drugs and not everyone will have the same side effects.
Another possible side effect is resistance to medication, which means the medication isnt working as well as it should.
You can lower the chance of resistance to medication by choosing effective medication, by not missing doses and by using a combination of medications instead of just one.
Please tell your doctor if you have any symptoms you are concerned about rather than stopping your medication on your own.
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How Do I Talk To My Partner About Their Risk Of Acquiring Hiv
People living with HIV can involve their partners in their treatment plans. Research shows that adhering to treatment often can improve with support from loving relationships and from the community.
Pre-exposure prophylaxis , in which an HIV-negative person takes antiretroviral medication to prevent infection, can be part of the conversation. Learn more about PrEP.
Antiretroviral Drug Side Effects And Management
HIV drugs have improved over the years, and serious side effects are less likely than they used to be. However, HIV drugs can still cause side effects. Some are mild, while others are more severe or even life-threatening. A side effect can also get worse the longer a drug is taken.
Its possible for other medications to interact with HIV drugs, causing side effects. Other health conditions can also make the side effects from HIV drugs worse. For these reasons, when starting any new drug, people with HIV should tell their healthcare provider and pharmacist about all the other medications, supplements, or herbs theyre taking.
In addition, if any new or unusual side effects occur, people with HIV should call their healthcare provider. They should do this even if theyve been on the medication for a long time. It can take months or years to start reacting to a drug.
For serious side effects, a healthcare provider might make sure that its the medication and not another factor thats causing the symptoms. If the drug is to blame, they might switch treatment to another antiretroviral drug. However, switching treatments isnt easy. They need to be sure that the new treatment will still work and that it wont cause even more severe side effects.
Here are some of the more common side effects from antiretroviral drugs and tips for managing them.
Examples of drugs that may cause it:
- abacavir
What might help:
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What Does It Mean To Be Durably Undetectable
Taking antiretroviral therapy daily as prescribed to suppress HIV levels leads to an undetectable status. A person is considered to have a durably undetectable viral load if their viral load remains undetectable for at least six months after their first undetectable test result. It is essential to continue to take every pill every day as directed to maintain an undetectable viral load.
Who Should And Shouldn’t Take Antivirals
While children, pregnant women, people who are immunocompromised, and those with multiple chronic conditions can still be prescribed antivirals, they should be careful, says Khubchandani.;
For instance, “some antiviral drugs can travel from mothers’ milk to babies, where side effects can be severe or unknown due to lack of research,” he says.;
Research on how antivirals affect these groups is often limited and conducting the research can be risky in an already high-risk population, says Khubchandani. Take Valtrex, for example.
Valtrex is used primarily to treat herpes infections. However, there’s not enough on the effects of the drug during pregnancy. Therefore, whether or not a pregnant woman should take it should be discussed with her doctor.;
Overall, whether or not an antiviral is the right course of treatment will depend on the individual.;
“Each person is unique disease type, health profile, blood markers, to check for liver and kidney function, and several other factors … have to be considered before prescribing,” says Khubchandani.
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How Hiv Treatment Works
HIV treatment does not cure HIV, but it stops the virus from reproducing in your body. It can reduce the amount of virus in the blood to undetectable levels, meaning that you cannot pass on HIV.
Treatment with anti-HIV drugs is sometimes called combination therapy because people usually take three different drugs at the same time ;often combined into one tablet.
It’s also known as antiretroviral therapy , or highly active antiretroviral therapy – HAART for short.
What Will Happen If I Skip My Arv For 2 Days
Missing doses of HIV medicines can reduce their usefulness and increase the possibility of developing drug resistance, which makes certain HIV drugs lose their effectiveness. If you realize you have missed a dose, go ahead and take the medication as soon as you can, then take the next dose at your usual scheduled time.
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What Is An Undetectable Viral Load
The aim of HIV treatment is to make you undetectable. This means that your viral load is so low that it cant be detected by the tests used to measure it.
Different laboratories may have different cut off points when classifying an undetectable viral load. However, most clinics in the UK classify undetectable as being below 20 copies/ml.
When you’re on effective treatment and have an undetectable viral load, you cannot pass on the virus and HIV is not able to damage your immune system.
A large study called PARTNER looked at 888 gay and straight couples where one partner was HIV positive and one was HIV negative. Results found that where the HIV positive partner was on treatment and had an undetectable viral load, there were no cases of HIV transmission whether they had anal or vaginal sex without a condom.
A follow-up study PARTNER 2 also reported zero transmissions after almost 800 gay couples had sex more than 77,000 without condoms.
Why Is Hiv Treatment Important
Getting and staying on HIV treatment because it reduces the amount of HIV in your blood to a very low level. This keeps you healthy and prevents illness. There is also a major prevention benefit. People living with HIV who take HIV medication daily as prescribed and get and keep an undetectable viral load have effectively no risk of sexually transmitting HIV to their HIV-negative partners. This is called treatment as prevention.
If left untreated, HIV attacks your immune system and can allow different types of life-threatening infections and cancers to develop. If your CD4 cell count falls below a certain level, you are at risk of getting an opportunistic infection. These are infections that dont normally affect people with healthy immune systems but that can infect people with immune systems weakened by HIV infection. Your health care provider may prescribe medicines to prevent certain infections.
HIV treatment is most likely to be successful when you know what to expect and are committed to taking your medicines exactly as prescribed. Working with your health care provider to develop a treatment plan will help you learn more about HIV and manage it effectively.
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