Nurses Compass
Drug Guide
Abacavir Sulfate
Classification
Therapeutic: Antiretroviral agent
Pharmacological: Nucleoside reverse transcriptase inhibitor (NRTI)
FDA Approved Indications
- Treatment of HIV-1 infection in combination with other antiretroviral agents
Mechanism of Action
Inhibits HIV-1 reverse transcriptase enzyme, causing chain termination during viral DNA synthesis, thereby blocking viral replication.
Dosage and Administration
Adult: 300 mg twice daily or 600 mg once daily in combination therapy.
Pediatric: Dose based on body weight or age, typically 8 mg/kg twice daily for children 3 months and older.
Geriatric: Adjust dose based on renal and hepatic function; no specific geriatric dosing, but caution advised.
Renal Impairment: Adjust dose in severe renal impairment; use with caution.
Hepatic Impairment: Use with caution in hepatic impairment; no specific dose adjustment recommended.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed, crosses blood-brain barrier.
Metabolism: Minimal hepatic metabolism; primarily excreted unchanged.
Excretion: Renal excretion; dose adjustment needed in renal impairment.
Half Life: Approximately 2 hours.
Contraindications
- Hypersensitivity to abacavir or any component of the formulation.
Precautions
- Risk of hypersensitivity reactions, especially in patients with HLA-B*57:01 allele, which predisposes to severe hypersensitivity. Prior to initiation, test for HLA-B*57:01 in appropriate populations.
- Use with caution in patients with cardiovascular disease, as hypersensitivity reactions can include symptoms like fever, rash, gastrointestinal symptoms, and respiratory symptoms.
Adverse Reactions - Common
- Nausea (Common)
- Headache (Common)
- Fatigue (Common)
Adverse Reactions - Serious
- Hypersensitivity reactions, potentially severe or life-threatening (Rare but serious)
- Lactic acidosis and hepatomegaly with steatosis (Rare)
Drug-Drug Interactions
- May interact with other hepatotoxic drugs, or drugs affecting renal function.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Assess for signs of hypersensitivity reactions, baseline liver function, renal function, and HLA-B*57:01 status before initiation.
Diagnoses:
- Risk for hypersensitivity reaction
- Risk for hepatic or renal impairment
Implementation: Administer as prescribed, monitor for adverse reactions, especially hypersensitivity, and educate the patient about early symptoms.
Evaluation: Monitor viral load, CD4 count, and adverse reaction symptoms to assess efficacy and safety.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report any symptoms of hypersensitivity immediately, such as rash, fever, or difficulty breathing.
- Do not stop medication without consulting healthcare provider.
- Inform about the importance of HLA-B*57:01 testing before initiation.
Special Considerations
Black Box Warnings:
- Severe hypersensitivity reactions can be life-threatening. Discontinue at first sign of hypersensitivity.
- Genetic testing for HLA-B*57:01 is recommended prior to starting therapy.
- Potential for lactic acidosis and hepatomegaly with steatosis.
Genetic Factors: Presence of HLA-B*57:01 allele increases risk of hypersensitivity.
Lab Test Interference: None specified.
Overdose Management
Signs/Symptoms: Nausea, vomiting, hypersensitivity symptoms, hypotension, and hypothermia.
Treatment: Supportive care, monitor vital signs, and provide symptomatic treatment. No specific antidote.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable under recommended storage conditions.