Kaletra is a fixed-dose combination antiretroviral medication containing lopinavir and ritonavir, designed for the treatment of human immunodeficiency virus (HIV-1) infection in adults and pediatric patients. As a protease inhibitor boosted by ritonavir, it plays a critical role in suppressing viral replication, increasing CD4 cell counts, and reducing HIV-related morbidity and mortality. It is indicated for use in combination with other antiretroviral agents as part of a complete treatment regimen, adhering to current clinical guidelines for HIV therapy. Kaletra offers a well-established efficacy and safety profile, supported by extensive clinical experience and long-term data.

Features

• Fixed-dose combination of lopinavir 200 mg and ritonavir 50 mg per tablet
• Available in tablet and oral solution formulations
• Ritonavir-boosted mechanism enhances lopinavir pharmacokinetics
• Does not require refrigeration for tablets (oral solution must be refrigerated)
• Dosing flexibility with twice-daily administration
• Coated tablet designed to mitigate taste-related issues

Benefits

• Achieves and maintains viral suppression below detectable limits
• Increases CD4+ T-cell counts, supporting immune reconstitution
• Reduces risk of HIV transmission and disease progression
• High genetic barrier to resistance compared to some other antiretroviral classes
• Well-suited for both treatment-naïve and treatment-experienced patients
• Supported by long-term real-world and clinical trial data

Common use

Kaletra is used as part of combination antiretroviral therapy (cART) for the management of HIV-1 infection. It is commonly prescribed in adult and pediatric patients aged 14 days and older, in accordance with body weight and surface area calculations for younger populations. It may be used in first-line regimens or as a switch option in virologically suppressed patients. Kaletra is also utilized in certain scenarios of post-exposure prophylaxis (PEP) and is considered in special populations such as pregnant individuals, under careful monitoring.

Dosage and direction

The standard adult dosage is 400 mg lopinavir/100 mg ritonavir (2 tablets) twice daily, taken with or without food. For treatment-naïve adults, an alternative once-daily dosing regimen of 800 mg lopinavir/200 mg ritonavir (4 tablets) may be considered. Pediatric dosing is weight-based or body surface area-based; consult official prescribing information for detailed tables. Tablets should be swallowed whole and not chewed, crushed, or broken. The oral solution should be administered using the provided dosing syringe or cup. Adherence to the prescribed schedule is critical to maintain therapeutic drug levels and prevent resistance.

Precautions

• Monitor liver function tests at baseline and during treatment; use with caution in patients with hepatic impairment, including hepatitis B or C coinfection.
• May cause PR interval prolongation—use caution in patients with pre-existing cardiac conduction disorders or those taking other QT-prolonging drugs.
• Pancreatitis has been reported; discontinue if symptoms occur (e.g., nausea, vomiting, abdominal pain).
• May exacerbate diabetes mellitus or result in hyperglycemia; monitor blood glucose.
• Redistribution/accumulation of body fat has been observed with protease inhibitors.
• Increased bleeding risk in hemophiliacs has been reported.
• Resistance testing is recommended prior to initiation in treatment-experienced patients.

Contraindications

• Hypersensitivity to lopinavir, ritonavir, or any component of the formulation.
• Coadministration with drugs highly dependent on CYP3A or CYP2D6 for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events:
  • Alfuzosin
  • Amiodarone
  • Colchicine (in patients with renal or hepatic impairment)
  • Dihydroergotamine
  • Ergotamine
  • Lovastatin
  • Lurasidone
  • Methylergonovine
  • Midazolam (oral)
  • Pimozide
  • Ranolazine
  • Sildenafil (for pulmonary arterial hypertension)
  • Simvastatin
  • Triazolam
• Coadministration with potent CYP3A inducers such as rifampin, which may significantly decrease lopinavir concentrations.

Possible side effect

Common (≥10%): diarrhea, nausea, vomiting, abdominal pain, headache, asthenia. Less common (1–10%): rash, insomnia, hypertriglyceridemia, hypercholesterolemia, increased ALT/AST. Rare (<1%): pancreatitis, severe skin reactions, AV block, renal stones, immune reconstitution inflammatory syndrome (IRIS). Laboratory abnormalities: elevated triglycerides, total cholesterol, glucose, and liver enzymes.

Drug interaction

Kaletra is a potent inhibitor of CYP3A and CYP2D6 and may increase concentrations of drugs metabolized by these pathways. It may also induce CYP1A2, CYP2C9, CYP2C19, and UGT1A1. Key interactions include:

• Anticonvulsants (e.g., carbamazepine, phenytoin): may decrease lopinavir levels.
• Antifungals (e.g., ketoconazole, itraconazole): increased azole concentrations.
• Sedative/hypnotics: contraindicated with oral midazolam and triazolam.
• Statins: avoid simvastatin and lovastatin; use atorvastatin or rosuvastatin with caution.
• Anticoagulants: monitor warfarin closely.
• Oral contraceptives: alternative non-hormonal methods are recommended.
• PDE5 inhibitors (e.g., sildenafil for erectile dysfunction): reduce sildenafil dose.
• Methadone: may decrease methadone levels; monitor for withdrawal.

Missed dose

If a dose is missed within 6 hours of the scheduled time, take it as soon as possible, then resume the normal schedule. If more than 6 hours have passed, skip the missed dose and take the next dose at the regular time. Do not double the dose. Consistent adherence is critical to maintain virologic suppression; consider using pill reminders or adherence tools.

Overdose

There is no specific antidote for Kaletra overdose. Treatment should consist of general supportive measures, including monitoring of vital signs and observation of clinical status. Hemodialysis is unlikely to be beneficial due to high protein binding. If occurring, manage symptoms supportively (e.g., antiemetics for nausea, electrolyte correction). Contact a poison control center for latest guidance.

Storage

• Tablets: Store below 30°C (86°F). Keep in original container; protect from moisture.
• Oral solution: Refrigerate (2–8°C/36–46°F); do not freeze. If stored at room temperature (≤25°C/77°F), use within 2 months.
• Keep out of reach of children and pets.

Disclaimer

This information is intended for healthcare professionals and is not a substitute for clinical judgment or official prescribing information. Treatment decisions must be based on the individual patient’s condition, resistance profile, and current treatment guidelines. Always verify dosing in pediatric and special populations. Report adverse events to the appropriate regulatory authority.

Reviews

Kaletra has been extensively studied in clinical trials and real-world settings. In the pivotal M98-863 trial, Kaletra-based regimens demonstrated superior virologic response compared to nelfinavir in treatment-naïve patients. Long-term data show sustained efficacy and a predictable safety profile. It remains a recommended option in multiple international guidelines, including those from the DHHS and EACS. Clinician feedback often highlights its utility in resource-limited settings and patients with adherence challenges, though gastrointestinal side effects and lipid abnormalities are noted considerations. Patient-reported outcomes indicate general satisfaction with dosing convenience, though taste and pill burden are occasionally cited concerns with the solution and older formulations.