Generic Name

Emtricitabine

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Classification

FDA Approved Indications

• Treatment of HIV-1 infection in adults and children ≥3 months of age

Mechanism of Action

Emtricitabine is a nucleoside reverse transcriptase inhibitor that works by incorporating into viral DNA and terminating the DNA chain, thereby suppressing viral replication.

Dosage and Administration

Adult: 200 mg once daily, orally

Pediatric: Children 3 months and older: 2 mg/kg once daily (up to 200 mg), orally

Geriatric: Use with caution; no specific dose adjustment required but consider renal function

Renal Impairment: Dose adjustment required based on renal function; typically 200 mg every 48-72 hours depending on degree of impairment

Hepatic Impairment: Use with caution; no specific dose adjustment

Pharmacokinetics

Absorption: Rapidly absorbed after oral administration with high bioavailability (~93%)

Distribution: Wide distribution; cerebrospinal fluid concentrations approximately 70% of plasma levels

Metabolism: Minimal metabolism; primarily excreted unchanged

Excretion: Renal excretion; via glomerular filtration and active tubular secretion

Half Life: 10 hours

Contraindications

• Known hypersensitivity to emtricitabine or any component of the formulation

Precautions

• Renal impairment: reduce dose accordingly
• Lactic acidosis and hepatic steatosis risk, particularly in patients with advanced liver disease or mitochondrial DNA depletion syndrome
• Hepatitis B virus co-infection: incomplete HBV suppression may lead to flare upon discontinuation; consider monitoring and treatment as appropriate

Adverse Reactions - Common

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

Adverse Reactions - Serious

• Lactic acidosis (Rare)
• Hepatic enzyme elevations, hepatitis (Rare)
• New or worsening renal impairment (Rare)
• Severe skin reactions (Rare)

Drug-Drug Interactions

• Emtricitabine is compatible with many HIV medications; avoid in patients taking drugs that affect renal excretion or cause mitochondrial toxicity without proper monitoring

Drug-Food Interactions

• No significant food interactions known

Drug-Herb Interactions

• Limited data; caution with herbal products affecting liver or renal function

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed, at the same time daily
• Report symptoms of lactic acidosis (malaise, myalgia, respiratory distress), severe skin reactions, or any unusual symptoms immediately
• Maintain regular follow-up appointments for lab tests and clinical assessment

Special Considerations

Black Box Warnings:

• Lactic acidosis and severe hepatomegaly with steatosis
• Exacerbation of hepatitis B upon discontinuation

Genetic Factors: No specific genetic markers influencing response known

Lab Test Interference: May cause false elevations in serum aminotransferase levels

Overdose Management

Signs/Symptoms: Nausea, vomiting, increased risk of lactic acidosis, hepatic toxicity

Treatment: Supportive care; no specific antidote. Hemodialysis may be considered in severe cases due to renal elimination.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F). Keep container tightly closed.

Stability: Stable up to the expiration date listed on the package.