Abacavir
FDA Drug Information • Also known as: Abacavir
- Brand Names
- Abacavir
- Route
- ORAL
- Dosage Form
- TABLET, FILM COATED
- Product Type
- HUMAN PRESCRIPTION DRUG
⚠ Boxed Warning (Black Box)
WARNING HYPERSENSITIVITY REACTIONS WARNING: HYPERSENSITIVITY REACTIONS See full prescribing information for complete boxed warning. Serious and sometimes fatal hypersensitivity reactions have occurred with abacavir sulfate. ( 5.1 ) Hypersensitivity to abacavir is a multi-organ clinical syndrome. ( 5.1 ) Patients who carry the HLA-B*5701 allele are at higher risk of experiencing a hypersensitivity reaction to abacavir. ( 5.1 ) Abacavir tablet is contraindicated in patients with a prior hypersensitivity reaction to abacavir and in HLA-B*5701-positive patients. ( 4 ) Discontinue abacavir tablets as soon as a hypersensitivity reaction is suspected. Regardless of HLA-B*5701 status, permanently discontinue abacavir tablets if hypersensitivity cannot be ruled out, even when other diagnoses are possible. ( 5.1 ) Following a hypersensitivity reaction to abacavir, NEVER restart abacavir tablets or any other abacavir-containing product. ( 5.1 ) Serious and sometimes fatal hypersensitivity reactions, with multiple organ involvement, have occurred with abacavir sulfate. Patients who carry the HLA-B*5701 allele are at a higher risk of a hypersensitivity reaction to abacavir; although, hypersensitivity reactions have occurred in patients who do not carry the HLA-B*5701 allele [see Warnings and Precautions ( 5.1 )] . Abacavir is contraindicated in patients with a prior hypersensitivity reaction to abacavir and in HLA-B*5701-positive patients [see Contraindications ( 4 ), Warnings and Precautions ( 5.1 )] . All patients should be screened for the HLA-B*5701 allele prior to initiating therapy with abacavir or reinitiation of therapy with abacavir, unless patients have a previously documented HLA-B*5701 allele assessment. Discontinue abacavir tablets immediately if a hypersensitivity reaction is suspected, regardless of HLA-B*5701 status and even when other diagnoses are possible [see Contraindications ( 4 ), Warnings and Precautions ( 5.1 )]. Following a hypersensitivity reaction to abacavir, NEVER restart abacavir tablets or any other abacavir-containing product because more severe symptoms, including death can occur within hours. Similar severe reactions have also occurred rarely following the reintroduction of abacavir-containing products in patients who have no history of abacavir hypersensitivity [see Warnings and Precautions ( 5.1 )] .
Description
11 DESCRIPTION Abacavir sulfate is a synthetic carbocyclic nucleoside analogue with inhibitory activity against HIV-1. The chemical name of abacavir sulfate is ( 1 S,cis) -4-[2-amino-6- (cyclopropylamino)-9 H -purin-9-yl]-2-cyclopentene-1-methanol sulfate (salt) (2:1). Abacavir sulfate is the enantiomer with 1S , 4R absolute configuration on the cyclopentene ring. It has a molecular formula of (C 14 H 18 N 6 O) 2
What Is Abacavir Used For?
1 INDICATIONS AND USAGE Abacavir tablet, a nucleoside analogue human immunodeficiency virus (HIV-1) reverse transcriptase inhibitor, is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. Abacavir tablets USP 300 mg, in combination with other antiretroviral agents, are indicated for the treatment of human immunodeficiency virus (HIV-1) infection.
Dosage and Administration
2 DOSAGE AND ADMINISTRATION Before initiating abacavir tablets, screen for the HLA-B*5701 allele. ( 2.1 ) Adults: 600 mg daily, administered as either 300 mg twice daily or 600 mg once daily. ( 2.2 ) Pediatric Patients Aged 3 Months and Older: Administered either once or twice daily. Dose should be calculated on body weight (kg) and should not exceed 600 mg daily. ( 2.3 ) Patients with Hepatic Impairment: Mild hepatic impairment – 200 mg twice daily. ( 2.4 ) 2.1 Screening for HLA-B*5701 Allele prior to Starting Abacavir tablets Screen for the HLA-B*5701 allele prior to initiating therapy with abacavir tablets [see Boxed Warning, Warnings and Precautions ( 5.1 )] . 2.2 Recommended Dosage for Adults Patients The recommended dosage of abacavir sulfate for adults is 600 mg daily, administered orally as either 300 mg twice daily or 600 mg once daily, in combination with other antiretroviral agents. 2.3 Recommended Dosage for Pediatric Patients The recommended dosage of abacavir sulfate in HIV-1-infected pediatric patients aged 3 months and older is 8 mg per kg orally twice daily or 16 mg per kg orally once-daily (up to a maximum of 600 mg daily) in combination with other antiretroviral agents. Abacavir tablet is also available as a scored tablet for HIV-1-infected pediatric patients weighing greater than or equal to 14 kg for whom a solid dosage form is appropriate. Before prescribing abacavir tablets, children should be assessed for the ability to swallow tablets. If a child is unable to reliably swallow abacavir tablets, the oral solution formulation should be prescribed. The recommended oral dosage of abacavir tablets for HIV-1-infected pediatric patients is presented in Table 1. Table 1. Dosing Recommendations for Abacavir Scored Tablets in Pediatric Patients Weight (kg) Once-Daily Dosing Regimen Data regarding the efficacy of once-daily dosing is limited to subjects who transitioned from twice-daily dosing to once-daily dosing after 36 weeks of treatment [see Clinical Studies (14.2)] . Twice-Daily Dosing Regimen AM Dose PM Dose Total Daily Dose 14 to <20 1 tablet (300 mg) ½ tablet (150 mg) ½ tablet (150 mg) 300 mg ≥20 to <25 1½ tablets (450 mg) ½ tablet (150 mg) 1 tablet (300 mg) 450 mg ≥25 2 tablets (600 mg) 1 tablet (300 mg) 1 tablet (300 mg) 600 mg 2.4 Recommended Dosage for Patients with Hepatic Impairment The recommended dose of abacavir sulfate in patients with mild hepatic impairment (Child-Pugh Class A) is 200 mg twice daily. To enable dose reduction, abacavir oral solution (10 mL twice daily) should be used for the treatment of these patients. The safety, efficacy, and pharmacokinetic properties of abacavir have not been established in patients with moderate to severe hepatic impairment; therefore, abacavir sulfate is contraindicated in these patients.
Side Effects (Adverse Reactions)
6 ADVERSE REACTIONS The most commonly reported adverse reactions of at least moderate intensity (incidence greater than or equal to 10%) in adult HIV-1 clinical trials were nausea, headache, malaise and fatigue, nausea and vomiting, and dreams/sleep disorders. ( 6.1 ) The most commonly reported adverse reactions of at least moderate intensity (incidence greater than or equal to 5%) in pediatric HIV-1 clinical trials were fever and/or chills, nausea and vomiting, skin rashes, and ear/nose/throat infections. ( 6.2 ) To report SUSPECTED ADVERSE REACTIONS, contact Cipla Ltd. at 1-866-604-3268 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The following adverse reactions are discussed in other sections of the labeling: Serious and sometimes fatal hypersensitivity reactions [see Boxed Warning, Warnings and Precautions ( 5.1 )] . Lactic acidosis and severe hepatomegaly with steatosis [see Warnings and Precautions ( 5.2 )] . Immune reconstitution syndrome [see Warnings and Precautions ( 5.3 )] . Myocardial infarction [see Warnings and Precautions ( 5.4 )] . 6.1 Clinical Trials Experience in Adult Subjects Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Serious and Fatal Abacavir-Associated Hypersensitivity Reactions In clinical trials, serious and sometimes fatal hypersensitivity reactions have occurred with abacavir [see Boxed Warning, Warnings and Precautions ( 5.1 )]. These reactions have been characterized by 2 or more of the following signs or symptoms: (1) fever; (2) rash; (3) gastrointestinal symptoms (including nausea, vomiting, diarrhea, or abdominal pain); (4) constitutional symptoms (including generalized malaise, fatigue, or achiness); (5) respiratory symptoms (including dyspnea, cough, or pharyngitis). Almost all abacavir hypersensitivity reactions include fever and/or rash as part of the syndrome. Other signs and symptoms have included lethargy, headache, myalgia, edema, arthralgia, and paresthesia. Anaphylaxis, liver failure, renal failure, hypotension, adult respiratory distress syndrome, respiratory failure, myolysis, and death have occurred in association with these hypersensitivity reactions. Physical findings have included lymphadenopathy, mucous membrane lesions (conjunctivitis and mouth ulcerations), and maculopapular or urticarial rash (although some patients had other types of rashes and others did not have a rash). There were reports of erythema multiforme. Laboratory abnormalities included elevated liver chemistries, elevated creatine phosphokinase, elevated creatinine, and lymphopenia, and abnormal chest x-ray findings (predominantly infiltrates, which were localized). Additional Adverse Reactions with Use of Abacavir sulfate Therapy-Naive Adults : Treatment-emergent clinical adverse reactions (rated by the investigator as moderate or severe) with a greater than or equal to 5% frequency during therapy with abacavir sulfate 300 mg twice daily, lamivudine 150 mg twice daily, and efavirenz 600 mg daily compared with zidovudine 300 mg twice daily, lamivudine 150 mg twice daily, and efavirenz 600 mg daily from CNA30024 are listed in Table 2. Table 2. Treatment-Emergent (All Causality) Adverse Reactions of at Least Moderate Intensity (Grades 2-4, Greater than or Equal to 5% Frequency) in Therapy-Naive Adults (CNA30024 This trial used double-blind ascertainment of suspected hypersensitivity reactions. During the blinded portion of the trial, suspected hypersensitivity to abacavir was reported by investigators in 9% of 324 subjects in the abacavir group and 3% of 325 subjects in the zidovudine group. ) through 48 Weeks of Treatment Adverse Reaction Abacavir sulfate plus Lamivudine plus Efavirenz (n = 324) Zidovudine plus Lamivudine plus Efavirenz (n = 325) Dreams/sleep disorders 10% 10%...
Drug Interactions
7 DRUG INTERACTIONS Methadone: An increased methadone dose may be required in a small number of patients. ( 7.1 ) Riociguat: The riociguat dose may need to be reduced. ( 7.2 ) 7.1 Methadone In a trial of 11 HIV-1-infected subjects receiving methadone-maintenance therapy with 600 mg of abacavir sulfate twice daily (twice the currently recommended dose), oral methadone clearance increased [see Clinical Pharmacology ( 12.3 )] . This alteration will not result in a methadone dose modification in the majority of patients; however, an increased methadone dose may be required in a small number of patients. 7.2 Riociguat Coadministration with fixed-dose abacavir/dolutegravir/lamivudine resulted in increased riociguat exposure, which may increase the risk of riociguat adverse reactions [see Clinical Pharmacology ( 12.3 )] . The riociguat dose may need to be reduced. See full prescribing information for ADEMPAS (riociguat).
Contraindications
4 CONTRAINDICATIONS Presence of HLA-B*5701 allele. ( 4 ) Prior hypersensitivity reaction to abacavir. ( 4 ) Moderate or severe hepatic impairment. ( 4 ) Abacavir tablet is contraindicated in patients: who have the HLA-B*5701 allele [see Warnings and Precautions ( 5.1 )] . with prior hypersensitivity reaction to abacavir [see Warnings and Precautions ( 5.1 )] . with moderate or severe hepatic impairment [see Use in Specific Populations ( 8.6 )] .
Pregnancy and Breastfeeding
8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to abacavir sulfate during pregnancy. Healthcare Providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Available data from the APR show no difference in the overall risk of birth defects for abacavir compared with the background rate for birth defects of 2.7% in the Metropolitan Atlanta Congenital Defects Program (MACDP) reference population (see Data) . The APR uses the MACDP as the U.S. reference population for birth defects in the general population. The MACDP evaluates women and infants from a limited geographic area and does not include outcomes for births that occurred at less than 20 weeks' gestation. The rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15% to 20%. The background risk for major birth defects and miscarriage for the indicated population is unknown. In animal reproduction studies, oral administration of abacavir to pregnant rats during organogenesis resulted in fetal malformations and other embryonic and fetal toxicities at exposures 35 times the human exposure (AUC) at the recommended clinical daily dose. However, no adverse developmental effects were observed following oral administration of abacavir to pregnant rabbits during organogenesis, at exposures approximately 9 times the human exposure (AUC) at the recommended clinical dose (see Data) . Data Human Data: Based on prospective reports to the APR of exposures to abacavir during pregnancy resulting in live births (including over 1,300 exposed in the first trimester and over 1,300 exposed in second/third trimester), there was no difference between the overall risk of birth defects for abacavir compared with the background birth defect rate of 2.7% in the U.S. reference...
Overdosage
10 OVERDOSAGE There is no known specific treatment for overdose with abacavir sulfate. If overdose occurs, the patient should be monitored and standard supportive treatment applied as required. It is not known whether abacavir can be removed by peritoneal dialysis or hemodialysis.
How Supplied
16 HOW SUPPLIED/STORAGE AND HANDLING Abacavir tablets USP 300 mg, containing abacavir sulfate equivalent to 300 mg abacavir are yellow coloured, capsule shaped, biconvex, film coated tablets, having scoreline on both sides with "5" and "14" debossed on either side of scoreline on one side. They are packaged as follows: Bottles of 60 tablets (NDC 69097-514-03). Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.]
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.