Fixed-Dose Combination: This tablet contains a fixed-dose combination of two active ingredients: Lopinavir (A), an HIV protease inhibitor, and Ritonavir (B), a pharmacokinetic boosting agent.
Pediatric Formulation: This specific strength (100 mg Lopinavir/25 mg Ritonavir) is formulated for pediatric use. It is designed to provide a convenient and accurate way to dose children based on their body weight.
Pharmacokinetic Booster: Ritonavir is included at a low dose not for its direct antiviral effect, but to inhibit the metabolism of Lopinavir, thereby increasing its concentration in the bloodstream.
Component of cART: This combination is a core component of combination antiretroviral therapy (cART) and must be used with other antiretroviral agents to provide a complete and effective treatment regimen.
Advantages
Accurate Pediatric Dosing: The fixed-dose tablet provides a convenient and accurate way to administer a precise dose to children, reducing the risk of medication errors associated with liquid formulations.
Improved Adherence: The combination tablet simplifies the treatment regimen for children by reducing the number of pills they need to take, which is a major factor in improving adherence and treatment success.
Potent Antiviral Activity: The combination of Lopinavir and Ritonavir is a powerful regimen that provides strong and sustained viral suppression, effectively reducing the HIV viral load.
High Barrier to Resistance: As a potent protease inhibitor, Lopinavir has a high genetic barrier to resistance, meaning the virus is less likely to develop mutations that would render the drug ineffective.
Uses
Pediatric HIV-1 Infection: Indicated for the treatment of HIV-1 infection in pediatric patients (from 6 months of age), in combination with other antiretroviral agents.
Prevention of Mother-to-Child Transmission: This combination is a key component of regimens used to prevent the transmission of HIV from mother to child.
Post-Exposure Prophylaxis (PEP): It can be used as a component of PEP regimens to prevent HIV infection in children following a potential exposure.
Treatment-Naïve and -Experienced Patients: The combination is effective in both children who are new to HIV treatment and those who have failed previous regimens.
Nature
Drug Classes: Lopinavir is a protease inhibitor (PI) and Ritonavir is also a PI, but it is primarily used as a cytochrome P450 (CYP450) inhibitor.
Mechanism of Action (Lopinavir): Lopinavir works by selectively inhibiting the viral enzyme protease, which is essential for the cleavage of viral polyproteins into functional proteins. This results in the production of immature, non-infectious viral particles.
Mechanism of Action (Ritonavir): At a low dose, Ritonavir is a potent inhibitor of the CYP3A4 enzyme in the liver. By blocking this enzyme, it prevents the rapid metabolism of Lopinavir, leading to higher and more sustained therapeutic concentrations.
Side Effects: Common side effects include gastrointestinal issues like diarrhea, nausea, and vomiting. There is also a potential for metabolic abnormalities such as high blood lipids and insulin resistance.
Storage
Temperature: Store the tablets at a controlled room temperature, typically between 20∘C to 25∘C (68∘F to 77∘F).
Protection: Keep the tablets in their original, tightly closed container, protected from light and moisture.
Administration: The tablets can be taken with or without food and should be swallowed whole. They should not be crushed, broken, or chewed.
Patient Compliance: Patients must be educated on the importance of taking every dose as prescribed and on time to prevent the development of viral resistance and to ensure long-term treatment success.
