Abacavir/lamivudine

Administration

• Type: Antiviral
• Dosage Forms: TAB 600mg, 300mg
• Routes of Administration: Oral
• Common Trade Names: Epzicom

Adult Dosing

HIV infection

• 1 tab PO daily

Pediatric Dosing

HIV infection

• >25kg: 1 tab PO daily

Special Populations

Pregnancy Rating

• Abacavir: Benefits outweigh risks during pregnancy
• Lamivudine: Benefits outweigh risks during pregnancy

Lactation risk

• Avoid breastfeeding

Renal Dosing

• Adult:
  • CrCl <50: Avoid use
• Pediatric:
  • CrCl <50: Avoid use

Hepatic Dosing

• Adult:
  • Child-Pugh Class A: Avoid use
  • Child-Pugh Class B or C: Contraindicated
• Pediatric:
  • Child-Pugh Class A: Avoid use
  • Child-Pugh Class B or C: Contraindicated

Contraindications

• Allergy to class/drug
• HLA-B*5701 Positive pts
• Hepatic impairment

Adverse Reactions

Serious

• Hypersensitivity reaction
• Anaphylaxis
• Stevens-Johnson syndrome
• Toxic epidermal necrolysis
• Erythema multiforme
• MI
• Lactic acidosis
• Hepatomegaly w/ steatosis
• Pancreatitis
• HBV exacerbation, post-treatment
• Peripheral neuropathy
• Anemia, severe
• Rhabdomyolysis
• Immune reconstitution syndrome
• Autoimmune disorders

Common

• Insomnia, depression, fatigue, abnormal dreams
• Headache, dizziness
• Nausea, diarrhea, abdominal pain,
• Rash
• Fever
• Anxiety
• Hyperamylasemia

Pharmacology

• Half-life:
  • Abacavir: 1.5h
  • Lamivudine: 5-7h
• Metabolism:
  • Abacavir: Liver
  • Lamivudine: Intracellular; active metabolite
• Excretion:
  • Abacavir: Urine 82.2% (1.2% unchanged), feces 16%
  • Lamivudine: Urine (primarily unchanged)

Mechanism of Action

Both drugs inhibit reverse transcriptase and incorporates into viral DNA, resulting in chain termination