Lopinavir + Ritonavir

Allopathic
Indications

Approved Indications:

  • HIV-1 Infection (in combination with other antiretroviral agents):
    • Indicated for the treatment of HIV-1 infection in adults and pediatric patients aged 14 days and older.
    • Suitable for both treatment-naïve and treatment-experienced patients.

Clinically Accepted Off-Label Uses:

  • Post-Exposure Prophylaxis (PEP) for HIV:
    • Used as part of a combination regimen following potential HIV exposure (e.g., occupational or sexual).
  • COVID-19 (Investigational Use):
    • Previously studied during the COVID-19 pandemic; however, current guidelines do not recommend its use due to lack of efficacy.
Dosage & Administration

Adults (≥18 years):

  • Standard Dose (Tablets):
    • 400 mg Lopinavir + 100 mg Ritonavir (2 tablets) twice daily.
  • Alternative Dose for Treatment-Naïve Patients:
    • 800 mg/200 mg once daily.
  • Oral Solution:
    • 5 mL (400 mg/100 mg) twice daily with food.

Pediatric Patients (14 days to 18 years):

  • Dosage based on body weight or body surface area (BSA).
  • BSA-Based Dosing Example:
    • 230 mg/m² of Lopinavir + 57.5 mg/m² of Ritonavir twice daily.
    • Do not exceed adult maximum dose.

Elderly:

  • No specific dose adjustment required; use with caution and monitor hepatic and renal function.

Renal Impairment:

  • No dosage adjustment necessary, but clinical monitoring is advised.

Hepatic Impairment:

  • Use with caution in mild to moderate impairment.
  • Contraindicated in severe hepatic impairment.

Route of Administration: Oral.
Administration Instructions:

  • Tablets should be swallowed whole (not crushed, broken, or chewed).
  • Oral solution should be taken with food.
Mechanism of Action (MOA)

Lopinavir is an HIV-1 protease inhibitor that blocks the cleavage of the Gag-Pol polyprotein, preventing the formation of mature infectious viral particles. Ritonavir, also a protease inhibitor, is included at a low dose to inhibit cytochrome P450 3A4 (CYP3A4) enzymes, thereby boosting plasma concentrations of Lopinavir. This pharmacokinetic enhancement improves antiviral efficacy by increasing the half-life and systemic exposure of Lopinavir. The combination leads to sustained suppression of viral replication.

Pharmacokinetics
  • Absorption: Oral bioavailability of Lopinavir is significantly increased by co-administration with Ritonavir and when taken with food.
  • Time to Peak Concentration: Approximately 4 hours (tablet), 5 hours (solution).
  • Protein Binding: Lopinavir ~98–99%; Ritonavir ~98–99%.
  • Metabolism:
    • Lopinavir: Extensively metabolized by CYP3A4.
    • Ritonavir: Metabolized by CYP3A4 and CYP2D6.
  • Half-Life:
    • Lopinavir: 5 to 6 hours.
    • Ritonavir: 3 to 5 hours.
  • Excretion:
    • Lopinavir: ~82% in feces, <2% in urine.
    • Ritonavir: ~86% in feces, ~11% in urine.
Pregnancy Category & Lactation

Pregnancy:

  • FDA Pregnancy Category C.
  • Use during pregnancy only if the potential benefit justifies the potential risk.
  • Often used as part of antiretroviral therapy in pregnant women under expert supervision.

Lactation:

  • Lopinavir and Ritonavir are excreted in breast milk in small amounts.
  • Breastfeeding is not recommended in HIV-infected mothers due to risk of postnatal HIV transmission.

Summary: Use in pregnancy and lactation only under clinical supervision. Avoid breastfeeding in HIV-positive mothers.

Therapeutic Class
  • Primary Class: Antiretroviral Agent
  • Subclass: Protease Inhibitor (PI) Combination
  • Pharmacokinetic Enhancer: Ritonavir boosts the plasma level of Lopinavir via CYP3A4 inhibition.
Contraindications
  • Known hypersensitivity to Lopinavir, Ritonavir, or any excipients.
  • Severe hepatic impairment.
  • Co-administration with drugs highly dependent on CYP3A4 for clearance and associated with serious or life-threatening reactions, such as:
    • Astemizole, terfenadine, cisapride, pimozide, ergot derivatives, lovastatin, simvastatin, triazolam, midazolam (oral).
  • Concurrent use with St. John's Wort.
Warnings & Precautions
  • Hepatotoxicity: Monitor liver enzymes regularly, especially in patients with hepatitis B/C or liver disease.
  • Pancreatitis: Discontinue if clinical signs or elevated amylase/lipase levels occur.
  • Cardiac Effects: May cause PR and QT prolongation. Caution in patients with conduction abnormalities.
  • Metabolic Effects: Monitor lipids and glucose due to risk of hyperlipidemia and hyperglycemia.
  • Immune Reconstitution Syndrome: May reveal latent opportunistic infections upon initiation.
  • Hemophilia: Increased bleeding episodes reported.
  • Oral Solution Warning: Contains ethanol and propylene glycol—use with caution in infants, pregnant women, and patients with hepatic dysfunction.
Side Effects

Common:

  • Gastrointestinal: Diarrhea, nausea, vomiting, abdominal pain
  • Metabolic: Hypertriglyceridemia, hypercholesterolemia
  • General: Headache, fatigue

Less Common:

  • Rash, taste disturbances, elevated liver enzymes

Serious/Rare:

  • Pancreatitis
  • Hepatotoxicity
  • PR and QT interval prolongation (arrhythmia risk)
  • Immune reconstitution inflammatory syndrome
  • Anemia or neutropenia (especially in pediatric patients)

Severity & Onset:

  • Most adverse effects are mild to moderate and occur within the first few weeks of treatment.
Drug Interactions

Major Drug-Drug Interactions:

  • CYP3A4 Inhibitors/Inducers:
    • May significantly increase or decrease Lopinavir/Ritonavir levels.
  • Contraindicated Drugs:
    • Simvastatin, lovastatin, rifampin, St. John’s Wort, ergot alkaloids, oral midazolam, triazolam.
  • Hormonal Contraceptives:
    • Reduced efficacy due to enzyme induction—alternative contraception recommended.
  • Warfarin:
    • May alter INR—monitor closely.

Food & Alcohol:

  • Take with food to improve absorption.
  • Avoid alcohol, particularly with the oral solution due to high ethanol content.
Recent Updates or Guidelines
  • COVID-19:
    • As per WHO and NIH, Lopinavir/Ritonavir is no longer recommended for COVID-19 due to lack of clinical efficacy.
  • HIV Treatment Guidelines (WHO, DHHS, EACS):
    • Still used in certain second-line or pediatric regimens.
    • Not first-line in most adult treatment-naïve patients due to pill burden and side effects.
  • Packaging and Formulation:
    • Oral solution reformulated for improved safety in pediatric use.
Storage Conditions

Tablets:

  • Store at 20°C to 25°C (68°F to 77°F).
  • Protect from moisture and light.
  • Keep in original container.

Oral Solution:

  • Store refrigerated at 2°C to 8°C (36°F to 46°F).
  • If refrigeration is not possible, can be stored at room temperature (≤25°C) for up to 2 months.
  • Shake well before use.
  • Do not freeze.
  • Keep away from direct sunlight.