ABACAVIR

Abacavir is an antiretroviral medication used in the treatment of HIV (Human Immunodeficiency Virus) infection.
Abacavirs chemical formula is C₁₄H₁₈N₆O.
Abacavir belongs to the class of nucleoside reverse transcriptase inhibitors (NRTIs).

CAS Number: 136470-78-5
Molecular Formula: C14H18N6O
Molecular Weight: 286.33
EINECS Number: 620-487-9

Synonyms: abacavir, Abacavir, Abacavir [INN], Abacavir [INN:BAN], abacavirum, Avacavir, ABC, 1592U89, Ziagen, Ziagen (TM), (+)-abacavir sulfate, (1R,4S)-abacavir sulfate, (+/-)-Abacavir, ((1S,4R)-4-(2-amino-6-(cyclopropylamino)-9H-purin-9-yl)cyclopent-2-en-1-yl)methanol, (1S,4R)-4-[2-Amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol, [(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]cyclopent-2-en-1-yl]methanol, [(1s,4r)-4-[2-amino-6-(cyclopropylamino)purin-9-yl]-1-cyclopent-2-enyl]methanol, {(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]cyclopent-2-en-1-yl}methanol, {(1S-cis)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]cyclopent-2-en-1-yl}methanol, 2-Cyclopentene-1-methanol, 4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-, (1S,4R)-, 2-Cyclopentene-1-methanol, 4-(2-amino-6-(cyclopropylamino)-9H-purin-9-yl)-, (1S-cis)-, (-)-CIS-4-(2-AMINO-6-(CYCLOPROPYLAMINO)-9H-PURIN-9-YL)-2-CYCLOPENTENE-1-METHANOL, 1592u89;[(1s,4r)-4-[2-amino-6-(cyclopropylamino)purin-9-yl]-1-cyclopent-2-enyl]methanol;[(1S,4R)-4-(2-AMINO-6-CYCLOPROPYLAMINO-PURIN-9-YL)-CYCLOPENT-2-ENYL]-METHANOL;2-Cyclopentene-1-methanol, 4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-, (1S,4R)-;2-Cyclopentene-1-methanol, 4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-, (1S-cis)-;(+/-)-4-[2-amino-6-(cyclopropylamino)-9h-purin-9-yl]-2-cyclopentene-1-methanol;Abacavir;Abacavir (see A105000)

Abacavir is a synthetic carbocyclic nucleoside analogue.
Abacavir mimics natural nucleosides used in DNA synthesis.
This allows it to interfere with viral replication.

Abacavir appears as a white to off-white crystalline powder.
It is moderately soluble in water.
Abacavir is typically formulated into tablets or oral solutions.

Abacavir works by inhibiting reverse transcriptase, an enzyme required for HIV replication.
Abacavir is converted inside cells to its active form (carbovir triphosphate).
This blocks viral DNA synthesis.

Abacavir exhibits selective antiviral activity against HIV-1 and HIV-2.
It reduces viral load in infected individuals.
This helps improve immune function.

Abacavir is generally used in combination therapy (HAART) with other antiretroviral drugs.
This improves treatment effectiveness and reduces resistance.
Abacavir is not used alone.

Abacavir is metabolized primarily in the liver and eliminated from the body after conversion to inactive metabolites.
Dosage must be carefully controlled.
Medical supervision is required.

Abacavir is best described as a synthetic antiviral nucleoside analogue used to inhibit HIV replication, playing a key role in combination antiretroviral therapy.
Abacavir is an antiviral nucleoside reverse transcriptase inhibitor used in combination with other antiretrovirals for the treatment of HIV.

Abacavir, sold under the brand name Ziagen among others, is a medication used to treat HIV/AIDS.
Similar to other nucleoside analog reverse-transcriptase inhibitors (NRTIs), abacavir is used together with other HIV medications, and is not recommended by itself.
Abacavir is taken by mouth as a tablet or solution and may be used in children over the age of three months.

Abacavir is generally well tolerated.
Common side effects include vomiting, insomnia (trouble sleeping), fever, and feeling tired.
Other common side effects include loss of appetite, headache, nausea (feeling sick), diarrhea, rash, and lethargy (lack of energy).

More severe side effects include hypersensitivity, liver damage, and lactic acidosis.
Genetic testing can indicate whether a person is at higher risk of developing hypersensitivity.
Symptoms of hypersensitivity include rash, vomiting, and shortness of breath.

Abacavir is in the NRTI class of medications, which work by blocking reverse transcriptase, an enzyme needed for HIV virus replication.
Within the NRTI class, abacavir is a carbocyclic nucleoside.
Abacavir has a rapid intracellular activation pathway, converting to carbovir monophosphate and then to the active triphosphate form.

This multi-step phosphorylation occurs within host cells.
Abacavir enables effective antiviral activity.
The drug exhibits a relatively long intracellular half-life of its active metabolite, allowing sustained antiviral effect.

This supports once- or twice-daily dosing.
Abacavir improves treatment adherence.
Abacavir undergoes hepatic metabolism primarily via alcohol dehydrogenase and glucuronidation pathways.

Abacavir is not significantly metabolized by cytochrome P450 enzymes.
This reduces potential drug–drug interactions.

Abacavir shows good penetration into the central nervous system (CNS) compared to some other antiretrovirals.
It can reach cerebrospinal fluid.
This is beneficial for controlling viral reservoirs.

Abacavir is generally well tolerated in most patients, aside from the risk of hypersensitivity reactions.
Common side effects may include mild gastrointestinal or systemic symptoms.
Monitoring is still required.

Melting point: 165°
alpha: D20 -59.7°; 43620 -127.8°; 36520 -218.1° (c = 0.15 in methanol)
Boiling point: 636.0±65.0 °C (Predicted)
Density: 1.70±0.1 g/cm³ (Predicted)
storage temp.: Sealed in dry, 2–8°C
solubility: DMSO (Slightly, Heated), Methanol (Slightly)
pKa: 5.01 (at 25℃)
form: Solid
color: Off-White to Pale Beige
Merck: 14,1
BCS Class: 3

Abacavir is a prodrug, meaning it is converted inside cells into its active form, carbovir triphosphate.
This active metabolite mimics natural nucleotides.
Abacavir becomes incorporated into viral DNA.

Once incorporated, it causes chain termination during DNA synthesis.
The viral DNA cannot be extended further.
This effectively stops HIV replication.

Abacavir shows high selectivity for viral reverse transcriptase over human DNA polymerases.
This reduces toxicity to human cells.
It improves its safety profile compared to less selective agents.

The drug is associated with a genetic hypersensitivity reaction linked to the HLA-B*57:01 allele.
Patients are usually screened before treatment.
This helps prevent severe adverse reactions.

Abacavir has good oral bioavailability, allowing effective absorption after ingestion.
Abacavir can be taken with or without food.
This improves patient convenience.

Abacavir demonstrates low resistance barrier when used alone, which is why combination therapy is essential.
Mutations in the virus can reduce its effectiveness.
Combination regimens help prevent this.

Abacavir is commonly included in fixed-dose combination drugs with other antiretrovirals.
This simplifies treatment regimens.
Abacavir improves patient adherence.

Abacavir shows limited penetration into certain body compartments, but still provides systemic antiviral activity.
Abacavir is effective in reducing viral load in blood.
This contributes to long-term HIV management.

Abacavir is a selective antiviral prodrug that inhibits HIV replication through chain termination, with important pharmacogenetic considerations and use in combination therapy.
Abacavir is often used in first-line HIV treatment regimens in combination with other NRTIs or antiretrovirals.
It forms part of standard therapy guidelines.

The drug contributes to long-term viral suppression and immune recovery when used correctly.
Abacavir helps increase CD4+ T-cell counts.
This improves patient outcomes.

Because of its mechanism, abacavir does not eliminate the virus completely but controls replication over time.
Continuous treatment is necessary.
This is typical of HIV therapy.

Abacavir is a clinically important antiretroviral with effective intracellular activation, sustained activity, and a key role in combination therapy, contributing to long-term HIV management.
Abacavir, in combination with other antiretroviral agents, is indicated for the treatment of HIV-1 infection.
Abacavir should be used in combination with other antiretroviral agents.

The drug is extensively metabolized via stepwise phosphorylation to 5′-mono-, di-, and triphosphate. 
Abacavir is well absorbed (>75%) and penetrates the CNS.  
The drug does not show any clinically significant drug–drug interactions. 

Abacavir has been reported to produce life-threatening hypersensitivity reactions.
Abacavir is a 2,6-diaminopurine that is (1S)-cyclopent-2-en-1-ylmethanol in which the pro-R hydrogen at the 4-position is substituted by a 2-amino-6-(cyclopropylamino)-9H-purin-9-yl group. 
A nucleoside analogue reverse transcriptase inhibitor (NRTI) with antiretroviral activity against HIV, it is used (particularly as the sulfate) with other antiretrovirals in combination therapy of HIV infection. 

Abacavir has a role as a HIV-1 reverse transcriptase inhibitor, an antiviral drug and a drug allergen.
Abacavir is contraindicated for people who have the HLA‑B*5701 allele or who have moderate or severe liver disease (hepatic impairment).

Uses:
Abacavir is a commonly used nucleoside analogue with potent antiviral activity against HIV-1.
Abacavir is primarily used in the treatment of HIV-1 infection as part of combination antiretroviral therapy (ART).
It helps reduce viral load in infected individuals.

This improves immune system function.
Abacavir is used in highly active antiretroviral therapy (HAART) regimens together with other drugs such as lamivudine and dolutegravir.
Combination therapy increases effectiveness.

This helps prevent drug resistance.
Abacavir is included in fixed-dose combination medications, such as Triumeq and Epzicom.
These simplify treatment by reducing pill burden.

This improves patient adherence.
Abacavir is used in both adult and pediatric HIV treatment.
Dosage is adjusted based on age and weight.

This allows flexible clinical use.
Abacavir is applied in long-term HIV management to maintain viral suppression.
It helps keep viral levels low over time.

This reduces disease progression.
In post-exposure prophylaxis (PEP) or specific treatment regimens, it may be used as part of combination therapy.
It helps reduce risk of infection after exposure.

This supports preventive strategies.
Abacavir is used in clinical research and antiviral studies.
It helps evaluate treatment strategies and drug combinations.

This advances HIV therapy development.
It is also used in resource-limited settings due to availability in combination therapies.

Abacavir supports global HIV treatment programs.
This improves accessibility.
Abacavir is used wherever suppression of HIV replication, immune system support, and long-term antiviral therapy are required, especially in combination treatment regimens.

Abacavir is used as a backbone nucleoside analogue in many standard HIV treatment regimens.
Abacavir is often combined with another NRTI and a third agent.
This forms the foundation of effective therapy.

In initial (first-line) HIV therapy, abacavir is prescribed for newly diagnosed patients when appropriate.
Abacavir helps rapidly reduce viral load.
This supports early disease control.

Abacavir is applied in treatment simplification strategies, where patients switch to fixed-dose combinations.
This reduces the number of pills taken daily.
Abacavir improves long-term adherence.

Abacavir is used in pediatric formulations, including oral solutions and adjusted-dose tablets.
This allows treatment in infants and children.
It supports early intervention.

In maintenance therapy, abacavir helps sustain viral suppression after initial control is achieved.
It contributes to stable long-term outcomes.
This is essential in chronic HIV management.

Abacavir is also used in co-infected patients (e.g., HIV with other conditions) as part of tailored regimens.
Its low interaction with cytochrome P450 enzymes is beneficial.
This allows flexible combination with other drugs.

Abacavir plays a role in treatment programs in global health initiatives, including large-scale HIV control efforts.
It is included in widely distributed combination therapies.
This improves access to treatment worldwide.

Abacavir is used in clinical trials and comparative studies to evaluate new HIV therapies and combinations.
Abacavir serves as a reference or component in regimens.
Abacavir is used wherever effective, combination-based suppression of HIV, long-term disease control, and accessible treatment strategies are required, across both clinical practice and global health programs.

Safety Profile:
Abacavir presents moderate to significant health hazards, primarily related to its potential for severe hypersensitivity reactions and systemic side effects.
It must be used under strict medical supervision.
Patient screening is essential before treatment.

Skin exposure (in pharmaceutical handling) may cause mild irritation, but the main concern is systemic exposure.
Repeated contact should be avoided in industrial settings.
Protective gloves are recommended.

Abacavir eye contact may cause irritation.
Symptoms can include redness and discomfort.
Eyes should be rinsed with water if exposure occurs.

Inhalation of dust (during manufacturing) may cause respiratory irritation.
Proper ventilation and dust control are required.
Respiratory protection may be necessary in industrial environments.

Ingestion or therapeutic use can cause serious hypersensitivity reactions, especially in individuals with the HLA-B*57:01 allele.
Symptoms may include fever, rash, gastrointestinal issues, and respiratory distress.
This reaction can be life-threatening if not recognized early.

Abacavir may also cause systemic side effects, such as nausea, fatigue, headache, and in rare cases liver toxicity or lactic acidosis.
Monitoring is required during treatment.
Dose and patient condition must be carefully managed.