Generic Name

Stribild (combination of Cobicistat, Elvitegravir, Emtricitabine, Tenofovir Disoproxil Fumarate)

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Classification

FDA Approved Indications

• Treatment of HIV-1 infection in adults

Mechanism of Action

This combination inhibits multiple steps in the HIV replication cycle: Elvitegravir inhibits integrase enzyme; Emtricitabine and Tenofovir Disoproxil Fumarate are nucleoside reverse transcriptase inhibitors; Cobicistat inhibits CYP3A enzyme, boosting levels of Elvitegravir.

Dosage and Administration

Adult: One tablet once daily with or without food

Pediatric: Not approved for pediatric use

Geriatric: Use with caution, dose adjustments based on renal function

Renal Impairment: Adjust dose or avoid based on renal function, eGFR thresholds

Hepatic Impairment: Use caution; no specific dose adjustment recommended

Pharmacokinetics

Absorption: Well absorbed orally

Distribution: Wide; crosses blood-brain barrier (Elvitegravir)

Metabolism: Cobicistat inhibits CYP3A, Elvitegravir metabolized via UGT1A1 and CYP3A

Excretion: Renal and fecal; primary renal for Tenofovir, monitor renal function

Half Life: Approximately 1.4 hours for Elvitegravir, longer when boosted by Cobicistat

Contraindications

• Hypersensitivity to components
• Use with concomitant use of certain drugs (see drug interactions)

Precautions

• Renal impairment, hepatic impairment, osteoporosis, hepatitis B co-infection; risk of lactic acidosis and severe hepatomegaly

Adverse Reactions - Common

• Nausea (frequent)
• Diarrhea (common)

Adverse Reactions - Serious

• Lactic acidosis (rare)
• Severe hepatotoxicity (rare)
• New or worsening renal impairment (rare)

Drug-Drug Interactions

• Metformin, statins, certain antiarrhythmics, other CYP3A substrates

Drug-Food Interactions

• No significant interactions

Drug-Herb Interactions

• St. John's Wort (reduce efficacy)

Nursing Implications

Patient/Family Teaching

• Take medication as prescribed, with or without food
• Report symptoms of renal issues, liver problems
• Avoid alcohol and certain supplements without healthcare advice

Special Considerations

Black Box Warnings:

• Lactic acidosis and severe hepatomegaly with steatosis

Genetic Factors: Genetic polymorphisms in UGT1A1 may affect metabolism

Lab Test Interference: May affect serum creatinine without affecting actual renal function

Overdose Management

Signs/Symptoms: Nausea, vomiting, fatigue, potential lactic acidosis

Treatment: Supportive care, monitor labs, hemodialysis if necessary for Tenofovir

Storage and Handling

Storage: Store at room temperature, away from moisture and heat

Stability: Stable through expiration date on package