When used with AZT, ddI and perhaps ddC, can delay HIV disease progression and death Zidovudine (AZT) was the first antiretroviral drug used in HIV and AIDS. It is expensive and has several adverse effects including nausea, vomiting, blood problems (anaemia and neutropenia) and myopathy (muscle weakness).
Full Answer
How do antiretroviral drugs work to treat HIV?
Antiretroviral drugs, the main category of drugs used for treatment of HIV, can block the virus from reproducing itself through targeting different chemicals the virus needs to make copies or perform other functions necessary its life cycle.
What is DDI used to treat?
Didanosine ( ddI, DDI ), sold under the brand name Videx, is a medication used to treat HIV/AIDS. It is used in combination with other medications as part of highly active antiretroviral therapy (HAART). It is of the reverse-transcriptase inhibitor class.
What is the function of DDI in HIV?
Within the cell, ddI is phosphorylated to the active metabolite of dideoxyadenosine triphosphate, ddATP, by cellular enzymes. Like other anti-HIV nucleoside analogs, it acts as a chain terminator by incorporation and inhibits viral reverse transcriptase by competing with natural dATP .
How does didanosine work to treat HIV?
Didanosine is a nucleoside analog reverse transcriptase inhibitor, or nuke. These drugs block the reverse transcriptase enzyme. This enzyme changes HIV’s genetic material (RNA) into the form of DNA. This has to occur before HIV’s genetic code gets inserted into an infected cell’s own genetic codes.
What is ddC drug?
Zalcitabine (2′-3′-dideoxycytidine, ddC), also called dideoxycytidine, is a nucleoside analog reverse-transcriptase inhibitor (NRTI) sold under the trade name Hivid. Zalcitabine was the third antiretroviral to be approved by the Food and Drug Administration (FDA) for the treatment of HIV/AIDS.
What is the action of antiretroviral drugs?
Antiretroviral therapy prevents the virus from multiplying, which reduces the amount of HIV in the body. This gives the immune system a chance to produce more CD4 cells.
What is the main drug used in the treatment of AIDS patients?
These drugs include Combivir (Zidovudine and Lamivudine), Trizivir (Zidovudine, Lamivudine and Abacavir), Epzicom (Abacavir and Lamivudine) and Truvada (Tenofovir and Lamivudine).
What are the drugs used and current treatments for AIDS?
Types of antiretroviralsnucleoside reverse transcriptase inhibitors (NRTIs or 'nukes')non-nucleoside reverse transcriptase inhibitors (NNRTIs or 'non-nukes')protease inhibitors.integrase inhibitors.entry inhibitors.
What is the mechanism of action of NRTI?
0:441:44HIV: Mechanisms of Action of NRTIs - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd copies it into viral DNA through the incorporation of naturally occurring nucleosides. TheMoreAnd copies it into viral DNA through the incorporation of naturally occurring nucleosides. The nucleoside reverse transcriptase inhibitors or NRT eyes compete with naturally-occurring nucleosides to
How does reverse transcriptase inhibitors work?
Reverse transcriptase inhibitors are active against HIV, a retrovirus. The drugs inhibit RNA virus replication by reversible inhibition of viral HIV reverse transcriptase, which reverse transcribes viral RNA into DNA for insertion into the host DNA sequence (see Fig. 51.6).
How do antiretroviral drugs work answers?
They work by blocking cell receptors, called CCR5 and CXCR4, respectively, and prevent HIV from attaching to the host cell, interrupting the HIV life cycle in its earliest stages. gp120 inhibitors, such as DS003, bind to the gp120 proteins HIV needs to attach to healthy cells.
What is the drug that prevents HIV replication?
Fusion inhibitors are a new class of drugs that act against HIV by preventing the virus from fusing with the inside of a cell, preventing it from replicating. The group of drugs includes Enfuvirtide, also known as Fuzeon or T-20.
How do drugs help with HIV?
Drug treatments help reduce the HIV virus in your body, keep your immune system as healthy as possible and decrease the complications you may develop. Some of the drugs approved by the FDA for treating HIV and AIDS are listed below.
What are the factors that determine a treatment plan?
Three main factors will be considered when designing your treatment plan: Your willingness and readiness to begin therapy. The stage of your disease. Other health problems.
Is the FDA approved for HIV?
Other health problems. The U.S. Food and Drug Administration (FDA) has approved a number of drugs for treating HIV and AIDS. It's important that you take your medications exactly as prescribed. This is a crucial part of your treatment success.
WHAT IS DIDANOSINE?
Didanosine (Videx®, ddI), is a drug used as part of antiretroviral therapy (ART). It is manufactured by Bristol-Myers Squibb and by Barr Laboratories. Didanosine is also known as ddI or dideoxyinosine.
WHO SHOULD TAKE DIDANOSINE?
Didanosine was approved in 1991 as an antiretroviral drug (ARV) for people with HIV infection. The generic version was approved in 2004. It has been studied in adults and children more than 2 weeks old.
WHAT ABOUT DRUG RESISTANCE?
Many new copies of HIV are mutations. They are slightly different from the original virus. Some mutations can keep multiplying even when you are taking an ARV. When this happens, the drug will stop working. This is called "developing resistance" to the drug. See Fact Sheet 126 for more information on resistance.
HOW IS DIDANOSINE TAKEN?
Didanosine is available as a 200 mg chewable tablet (which can also be dissolved in water) and as a powder that is dissolved in water. Note: the 200 mg tablets became unavailable in October 2005. There is also an ?enteric coated? version of didanosine called Videx EC. It can be taken as a single capsule once a day.
WHAT ARE THE SIDE EFFECTS?
When you start any ART you may have temporary side effects such as headaches, high blood pressure, or a general sense of feeling ill. These side effects usually get better or disappear over time.
HOW DOES DIDANOSINE REACT WITH OTHER DRUGS?
Didanosine can interact with other drugs or supplements you are taking. These interactions can change the amount of each drug in your bloodstream and cause an under- or overdose. New interactions are constantly being identified. Make sure that your health care provider knows about ALL drugs and supplements you are taking.
What are the drugs used to treat HIV?
The drug families used to treat HIV are classified based on what part of the virus’ reproductive process they target. Nucleoside and nucleotide analogue reverse transcriptase inhibitors (NRTIs), for example, block reverse transcriptase. This is an enzyme the virus needs to infect white blood cells.
What is the main treatment for HIV?
Antiretroviral drugs, the main category of drugs used for treatment of HIV, can block the virus from reproducing itself through targeting different chemicals the virus needs to make copies or perform other functions necessary its life cycle.
What enzymes block HIV?
NRTIs block an enzyme of the human immunodeficiency virus called reverse transcriptase that allows HIV to infect human cells, particularly CD4 cells or lymphocytes. Reverse transcriptase converts HIV genetic material, which is RNA, into human genetic material, which is DNA.
What is the drug that binds to HIV?
A monoclonal antibody called ibalizumab (Trogarzo) binds the CD4 molecule (a receptor for HIV on cells), which prevents viral entry into the cell. Medical professionals administer the drug as an intravenous infusion of 2,000 mg once, then two weeks later at 2,000 mg again, followed by 800 mg every two weeks.
How does HIV get transmitted?
HIV is transmitted through blood and genital secretions; most people get it through sexual contact or sharing needles for illegal IV drug use. HIV can be controlled by a strict drug regimen, but left unchecked, it leads to AIDS. In AIDS, the immune system collapses and the body falls prey to secondary, opportunistic infections and cancers that typically kill the person.
How long does it take for a person to show signs of HIV?
Signs and symptoms begin around seven or eight years after HIV infection, which include weight loss, loss of energy and appetite, and swollen lymph nodes. There are 3 stages of HIV.
How does HIV work?
This is a unique drug in a new class that blocks viral entry by interacting with the C CR5 molecule on the surface of the CD4 cell. It is known that HIV first binds to the CD4 molecule on the surface of CD4 cells and then connects with the CCR5 or CXCR4 molecule.
Overview
Didanosine (ddI, DDI), sold under the brand name Videx, is a medication used to treat HIV/AIDS. It is used in combination with other medications as part of highly active antiretroviral therapy (HAART). It is of the reverse-transcriptase inhibitor class.
Didanosine was first described in 1975 and approved for use in the United States in 1991.
Adverse effects
The most common adverse events with didanosine are diarrhea, nausea, vomiting, abdominal pain, fever, headache, and rash. Peripheral neuropathy occurred in 21-26% of participants in key didanosine trials.
Pancreatitis is rarely observed but has caused occasional fatalities, and has black box warning status. Other reported serious adverse events are retinal changes, optic neuritis and alterations o…
Drug interactions
• A significant interaction has also been recorded with allopurinol, and administration of these drugs together should be avoided.
• Reduction in indinavir and delavirdine plasma levels have been shown to occur when administered simultaneously with didanosine; these drugs should be administered at different times.
Resistance
Drug resistance to didanosine does develop, though slower than to zidovudine (ZDV). The most common mutation observed in vivo is L74V in the viral pol gene, which confers cross-resistance to zalcitabine; other mutations observed include K65R and M184V .
Mechanism of action
Didanosine (ddI) is a nucleoside analogue of adenosine. It differs from other nucleoside analogues, because it does not have any of the regular bases, instead it has hypoxanthine attached to the sugar ring. Within the cell, ddI is phosphorylated to the active metabolite of dideoxyadenosine triphosphate, ddATP, by cellular enzymes. Like other anti-HIV nucleoside analogs, it acts as a chain terminator by incorporation and inhibits viral reverse transcriptase by competing with natural
Pharmacokinetics
Oral absorption of didanosine is fairly low (42%) but rapid. Food substantially reduces didanosine bioavailability, and the drug should be administered on an empty stomach. The half-life in plasma is only 1.5 hours, but in the intracellular environment more than 12 hours. An enteric-coated formulation is now marketed as well. Elimination is predominantly renal; the kidneys actively secrete didanosine, the amount being 20% of the oral dose.
History
The related pro-drug of didanosine, 2′,3′-dideoxyadenosine (ddA), was initially synthesized by Morris J. Robins (professor of Organic Chemistry at Brigham Young University) and R.K. Robins in 1964. Subsequently, Samuel Broder, Hiroaki Mitsuya, and Robert Yarchoan in the National Cancer Institute (NCI) found that ddA and ddI could inhibit HIV replication in the test tube and conducted initial clinical trials showing that didanosine had activity in patients infected with HIV. On behalf …
Further reading
• Robins MJ, McCarthy JR, Robins RK (January 1966). "Purine nucleosides. XII. The preparation of 2',3'-dideoxyadenosine, 2',5'-dideoxyadenosine, and 2',3',5'-trideoxyadenosine from 2'-deoxyadenosine". Biochemistry. 5 (1): 224–31. doi:10.1021/bi00865a029. PMID 5938940.
• Yarchoan R, Mitsuya H, Broder S (October 1988). "AIDS therapies". Scientific American. 259 (4): 110–9. Bibcode:1988SciAm.259d.110Y. doi:10.1038/scientificamerican1088-110. PMID 3072667.
Didanosine
What Is Didanosine?
- Didanosine (Videx®, ddI), is a drug used as part of antiretroviral therapy (ART). It is manufactured by Bristol-Myers Squibb and by Barr Laboratories. Didanosine is also known as ddI or dideoxyinosine. Didanosine is a nucleoside analog reverse transcriptase inhibitor, or nuke. These drugs block the reverse transcriptase enzyme. This enzyme changes ...
Who Should Take Didanosine?
- Didanosine was approved in 1991 as an antiretroviral drug (ARV) for people with HIV infection. The generic version was approved in 2004. It has been studied in adults and children more than 2 weeks old. There are no absolute rules about when to start ART. You and your health care provider should consider your CD4 cell count, your viral load, any symptoms you are having, and …
What About Drug Resistance?
- Many new copies of HIV are mutations. They are slightly different from the original virus. Some mutations can keep multiplying even when you are taking an ARV. When this happens, the drug will stop working. This is called "developing resistance" to the drug. See Fact Sheet 126 for more information on resistance. Sometimes, if your virus develops resistance to one drug, it will also h…
How Is Didanosine taken?
- Didanosine is available as a 200 mg chewable tablet (which can also be dissolved in water) and as a powder that is dissolved in water. Note: the 200 mg tablets became unavailable in October 2005. There is also an ?enteric coated? version of didanosine called Videx EC. It can be taken as a single capsule once a day. Videx EC does not contain a buffer, so side effects and drug interacti…
What Are The Side Effects?
- When you start any ART you may have temporary side effects such as headaches, high blood pressure, or a general sense of feeling ill. These side effects usually get better or disappear over time. The most common side effects of didanosine are diarrhea, headaches, vomiting and rash. Diarrhea, caused by the buffer in the tablets, is sometimes severe. Side effects are less commo…
How Does Didanosine React with Other Drugs?
- Didanosine can interact with other drugs or supplements you are taking.These interactions can change the amount of each drug in your bloodstream and cause an under- or overdose. New interactions are constantly being identified. Make sure that your health care provider knows about ALL drugs and supplements you are taking. Didanosine may be more effective if taken with hydr…