What is Kaletra Medication Used For? Side Effects and Dosage

What is Kaletra Medication Used For? Side Effects and Dosage

What is Kaletra (Lopinavir/Ritonavir)?

Kaletra, the trade name of a combination of the drugs lopinavir (LPV) and ritonavir (RNV), is a medication used in the treatment of human immunodeficiency virus (HIV), the virus responsible for the development of acquired immunodeficiency syndrome (AIDS) in the human body. Kaletra is referred to as a fixed-dose combination medication, meaning it is intended to reduce the number of tablets taken by a patient receiving antiretroviral treatment. The first of its two active ingredients, lopinavir, is a protease inhibitor (PI) used to block the virus’ use of the enzyme protease in its reproductive activities. The second, ritonavir, was originally designed as a protease inhibitor but has since found more use as a pharmacoenhancer, a drug included to enhance the effects of other drugs. It is used in Kaletra to block the activity of certain enzymes in the liver that would normally metabolize antiretroviral medications, reducing their efficacy. The drug was approved for sale in 2000 and is marketed by U.S. pharmaceutical company AbbVie.

What is It Used For?

Kaletra is used in the treatment of individuals with HIV Type 1 (HIV-1), the more common and infectious type of the virus. As a combination medication, it relies on the conjunctive mechanisms of its two active ingredients. Lopinavir, as a protease inhibitor, works by halting a process called proteolysis, in which the enzyme protease breaks large chains of protein molecules into smaller chains (called peptides). This process is exploited by the virus to create new viral DNA strands from ribonucleic acid, allowing the infection to advance to later stages in an individual. By halting proteolysis, lopinavir slows the infection and prevents a patient’s viral load (virus cells per unit of blood) from increasing.

To make Kaletra more effective, ritonavir is included as an inhibitor of the liver enzyme cytochrome P450 3A4 (abbreviated CYP3A4), which metabolizes other antiretroviral medications in the body leading to a decrease in blood levels of said medications. The inclusion of ritonavir thus helps maintain consistent levels of lopinavir in the body longer than if it were omitted.  

How to Take This Drug

Kaletra is available in tablet and liquid forms. The tablets should not be crushed, chewed, or broken and may be taken with or without food, while the liquid form should always be taken with food. Each formulation contains similar ratios of the two active ingredients (100 mg LPV to 25 mg RNV). Due to the possible interactions of grapefruit juice with both lopinavir and ritonavir, grapefruit and grapefruit juice should be avoided while taking Kaletra to avoid the risk of unpredictable blood levels and adverse effects. In the event of a missed dose, patients should never double their dosage to compensate and instead resume their normal dosage at the next scheduled time.

Kaletra Side Effects

Various side effects have been observed in patients taking Kaletra. Prior to taking this medicine, prospective patients should consult with their health care provider regarding other medications being taken, as these may interact and increase the risk of adverse effects.

The following side effects are common and often manageable:

  • nausea
  • headaches
  • diarrhea
  • dizziness
  • fatigue
  • changes in body fat shape and location
  • insomnia

The following side effects occur less frequently, but may require urgent care:

  • skin rash
  • changes in vision
  • numbness in hands or feet
  • weakness
  • fever
  • discoloring of urine or stool
  • wheezing, coughing, or shortness of breath

It should be noted that the liquid solution and certain sized tablets of Kaletra are not considered safe for pregnant women and should be avoided. Other forms have been found to be safe during pregnancy.


In adult patients, the standard recommended dose of Kaletra is 400 mg NPV and 100 mg RNV at a time, twice daily. In certain cases, for adult patients only, a once-daily dose is available, containing 800 mg and 200 mg of the respective active ingredients. In children weighing over 40 kg (88 lbs), the adult dosage is recommended. For patients weighing below 40 kg, smaller dosages depending on body weight are available. Children who have trouble swallowing tablets may be prescribed the liquid formulation of Kaletra.

Disclaimer: Please note that the contents of this article are for informational purposes only and should not be considered medical advice. This article, and other AIDS and HIV Information articles on AIDS Drugs Online, are not written by AIDS Drugs Online or reviewed by its staff for medical validity. All views and opinions expressed by the third-party authors are not endorsed by AIDS Drugs Online or its staff. Always consult a medical professional for medical advice.


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