Nurses Compass
Drug Guide
Darunavir Ethanolate
Classification
Therapeutic: Antiretroviral (HIV protease inhibitor)
Pharmacological: Protease inhibitor
FDA Approved Indications
- Treatment of HIV-1 infection in combination with other antiretroviral agents
Mechanism of Action
Darunavir inhibits the HIV-1 protease enzyme, preventing the cleavage of the Gag-Pol protein precursors. This results in the production of immature, non-infectious viral particles, thereby reducing viral load.
Dosage and Administration
Adult: 600 mg twice daily with food; may be adjusted based on patient's response and concomitant medications
Pediatric: Not approved for pediatric use
Geriatric: No specific dose adjustment recommended; consider renal and hepatic function
Renal Impairment: Use with caution; dosage adjustments may be necessary
Hepatic Impairment: Use with caution in patients with severe hepatic impairment; no specific dose adjustment established
Pharmacokinetics
Absorption: Well absorbed with bioavailability enhanced by food
Distribution: Extensively distributed in body tissues; protein binding approximately 95%
Metabolism: Primarily metabolized by CYP3A enzymes in the liver
Excretion: Primarily excreted in feces; minor amount in urine
Half Life: Approximately 15 hours
Contraindications
- Hypersensitivity to darunavir or any component of the formulation
Precautions
- Use with caution in patients with hypersensitivity reactions; may cause hepatotoxicity; monitor liver function; caution in patients with cardiovascular disease
Adverse Reactions - Common
- Nausea (Common)
- Headache (Common)
- Rash (Uncommon)
Adverse Reactions - Serious
- Allergic reactions including skin rash, pruritus, and hypersensitivity (Less common)
- Hepatotoxicity including elevated liver enzymes (Uncommon)
Drug-Drug Interactions
- Rifampin, which decreases darunavir levels; other CYP3A inhibitors and inducers affecting its levels
Drug-Food Interactions
- Avoid high-fat meals which may alter absorption
Drug-Herb Interactions
- Potential interactions with St. John’s Wort and other herbal products affecting CYP3A activity
Nursing Implications
Assessment: Monitor for signs of hypersensitivity, rash, and hepatotoxicity; assess liver function tests regularly
Diagnoses:
- Risk for ineffective tissue perfusion related to adverse drug reactions
Implementation: Administer with food; instruct patient to adhere to prescribed schedule; monitor for adverse reactions and interactions
Evaluation: Evaluate viral load suppression, monitor for side effects, and liver function tests regularly
Patient/Family Teaching
- Take medication with food at the same times daily
- Report any rash, allergic reactions, or signs of liver problems immediately
- Complete full course of therapy and do not stop medication without consulting healthcare provider
Special Considerations
Black Box Warnings:
- Potential for hepatitis B exacerbation upon discontinuation
Genetic Factors: None specified
Lab Test Interference: May cause increases in serum cholesterol and triglycerides
Overdose Management
Signs/Symptoms: Nausea, vomiting, dizziness, etc.
Treatment: Supportive care; no specific antidote; contact poison control; monitor vital signs and provide symptomatic treatment
Storage and Handling
Storage: Store at 25°C (77°F); Keep container tightly closed
Stability: Stable at room temperature for at least 24 months