Home Drug Guide Abacavir Sulfate and Lamivudine

Drug Guide

Generic Name

Abacavir Sulfate and Lamivudine

Brand Names Epzicom

Classification

Therapeutic: Antiretroviral (HIV-1 treatment)

Pharmacological: Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

FDA Approved Indications

  • Treatment of HIV-1 infection in combination with other antiretroviral agents

Mechanism of Action

Abacavir inhibits HIV-1 reverse transcriptase by incorporating into viral DNA, causing chain termination. Lamivudine also inhibits reverse transcriptase by causing DNA chain termination; together, they inhibit HIV replication.

Dosage and Administration

Adult: 300 mg of abacavir plus 300 mg of lamivudine once daily or in divided doses twice daily, as part of combination therapy.

Pediatric: Dose based on body weight, typically 8 mg/kg of abacavir and 4 mg/kg of lamivudine twice daily, with a maximum dose of 300 mg for each drug per dose.

Geriatric: Use with caution due to potential comorbidities and drug interactions; no specific dose adjustment, but renal and hepatic function should be considered.

Renal Impairment: Adjust dose according to renal function; generally, use with caution and monitor renal function.

Hepatic Impairment: Use with caution; dose adjustment may be necessary, especially in severe hepatic impairment.

Pharmacokinetics

Absorption: Rapidly absorbed orally.

Distribution: Widely distributed in body tissues.

Metabolism: Lamivudine minimally metabolized; abacavir metabolized in the liver via alcohol dehydrogenase.

Excretion: Primarily renally excreted for both drugs.

Half Life: Abacavir approximately 2.4 hours; lamivudine approximately 5-7 hours.

Contraindications

  • Hypersensitivity to abacavir or lamivudine.
  • HLA-B*5701 positive status (due to hypersensitivity risk).

Precautions

  • History of hypersensitivity reactions; hepatic or renal impairment; lactic acidosis risk.

Adverse Reactions - Common

  • Nausea (Common)
  • Headache (Common)
  • Fatigue (Common)

Adverse Reactions - Serious

  • Hypersensitivity reactions (Rare)
  • Lactic acidosis (Rare)
  • Hepatotoxicity (Rare)

Drug-Drug Interactions

  • Abacavir and lamivudine may interact with other drugs affecting the liver or renal function.
  • Use caution with drugs affecting CYP450 enzymes.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of hypersensitivity, adverse reactions, and efficacy of therapy.

Diagnoses:

  • Risk for ineffective tissue perfusion
  • Risk for injury due to hypersensitivity.

Implementation: Administer as prescribed, monitor labs regularly including liver and renal function.

Evaluation: Assess viral load and immune status to determine treatment efficacy.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report any hypersensitivity symptoms immediately.
  • Adhere to follow-up lab testing and doctor's appointments.

Special Considerations

Black Box Warnings:

  • Severe hypersensitivity reactions associated with HLA-B*5701 allele.
  • Lactic acidosis and hepatomegaly with steatosis.

Genetic Factors: Testing for HLA-B*5701 allele recommended before starting therapy.

Lab Test Interference: May affect certain lab tests; inform laboratory personnel.

Overdose Management

Signs/Symptoms: Potential for severe hypersensitivity or lactic acidosis.

Treatment: Supportive care; no specific antidote. Immediate medical attention required.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable under recommended storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.