Drug Guide
Indinavir sulfate
Classification
Therapeutic: Antiretroviral, protease inhibitor
Pharmacological: Protease inhibitor
FDA Approved Indications
- Treatment of HIV-1 infection in combination with other antiretroviral agents
Mechanism of Action
Indinavir inhibits the HIV-1 protease enzyme, preventing the cleavage of viral polyprotein precursors into mature, infectious viral particles, thereby inhibiting viral replication.
Dosage and Administration
Adult: Typically 800 mg every 8 hours, with or without food, as part of combination antiretroviral therapy.
Pediatric: Dosage determined by body weight, under specialist supervision.
Geriatric: Adjustments based on renal function and tolerability.
Renal Impairment: Use with caution; dosage adjustment may be necessary.
Hepatic Impairment: No specific adjustment; use with caution.
Pharmacokinetics
Absorption: Well absorbed orally; food may delay absorption but does not reduce overall absorption.
Distribution: Widely distributed; highly protein-bound (~60-65%).
Metabolism: Primarily hepatic via CYP3A4.
Excretion: Feces (main route), small amount in urine.
Half Life: Approximately 2-4 hours.
Contraindications
- Known hypersensitivity to indinavir or component ingredients.
Precautions
- Use with caution in patients with renal impairment, hepatic impairment, or kidney stones.
Adverse Reactions - Common
- Nephrolithiasis (kidney stones) (Less frequent; monitor renal function)
- Hyperbilirubinemia (Common)
- Rash (Common)
- Lipodystrophy, hyperlipidemia, elevated liver enzymes, nausea, diarrhea. (Variable)
Adverse Reactions - Serious
- Immune reconstitution syndrome (Rare)
- Stevens-Johnson syndrome and toxic epidermal necrolysis (Very rare)
- Hepatotoxicity (Rare)
- Acute renal failure (due to nephrolithiasis) (Less frequent)
Drug-Drug Interactions
- Ritonavir (potentiates indinavir levels), other CYP3A4 inhibitors or inducers, drugs affecting renal function.
Drug-Food Interactions
- High-fat meals may delay absorption; take consistently with or without food as advised.
Drug-Herb Interactions
- St. John’s Wort (may decrease efficacy).
Nursing Implications
Assessment: Monitor renal function, liver function, lipid profile, and presence of renal stones.
Diagnoses:
- Risk for renal stones, altered renal function, hyperlipidemia.
Implementation: Administer as prescribed; ensure adequate hydration to prevent kidney stones; monitor for adverse effects.
Evaluation: Assess renal function, adherence, and effectiveness of viral suppression.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Maintain adequate hydration (at least 48 ounces of water daily).
- Report signs of kidney stones (flank pain, blood in urine).
- Adhere to regular monitoring appointments.
- Be aware of potential side effects and drug interactions.
Special Considerations
Black Box Warnings:
- Risk of nephrolithiasis; recommend hydration and monitoring of renal function.
Genetic Factors: None specified.
Lab Test Interference: May slightly increase bilirubin levels without jaundice.
Overdose Management
Signs/Symptoms: Nausea, vomiting, dizziness, hypotension.
Treatment: Supportive care; no specific antidote; monitor renal function; provide hydration and symptomatic treatment.
Storage and Handling
Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).
Stability: Stable under recommended conditions for shelf life indicated in packaging.