Kaletra (Lopinavir/Ritonavir) - Oral

What Is Kaletra?

Kaletra is a combination ritonavir-boosted protease inhibitor (PI) that includes lopinavir and low-dose ritonavir. It's used to treat human immunodeficiency virus (HIV) infection in adults and children.

Kaletra works by inhibiting proteases (special enzymes). This decreases viral load (amount of HIV in the blood) and reduces the risk of developing infectious diseases due to a weakened immune system. Ritonavir boosts the level of lopinavir in the body by inhibiting cytochrome P450 3A4 (a particular liver enzyme). This strengthens the effect of the medication overall.

Kaletra is available only by prescription. It's available as a tablet, soft-gel capsule, and an oral solution for people who have difficulty swallowing.

Drug Facts

Generic Name: Lopinavir/Ritonavir

Brand Name(s): Kaletra

Drug Availability: Prescription

Therapeutic Classification: HIV protease inhibitors

Available Generically: No

Controlled Substance: N/A

Administration Route: Oral

Active Ingredient: Lopinavir and Ritonavir

Dosage Form(s): Tablets, oral solution

What Is Kaletra Used For?

Kaletra is a medication option to prevent HIV-1-related infections in adults, adolescents, and children above 14 days.

According to the Centers for Disease Control and Prevention (CDC), in 2019, around 38 million people were living with HIV around the world. Around 690,000 people died from AIDS-related illnesses in 2019. Kaletra is not a cure for HIV, but these medications may decrease the chance of developing HIV-related illnesses and acquired immunodeficiency syndrome (AIDS).

Following the discovery and widespread use of antiretroviral therapy (ART), such as protease inhibitors, the life expectancy of HIV-infected individuals has substantially increased.

How to Take Kaletra

Always read the prescription label and manufacturer's guidelines carefully. Ask your pharmacist or healthcare provider about anything you don't understand. 

Kaletra comes as a tablet and a solution (liquid) to take by mouth, usually twice a day or as prescribed. 

When taking tablets:

  • Take with or without food.
  • Swallow the tablets whole.
  • Do not split, chew, or crush them.

When taking Kaletra in solution form:

  • You must take it with food. 
  • Shake it well before each use to mix the medication evenly.
  • Use a dose-measuring spoon or cup to measure the dose correctly.
  • Do not use a household spoon as it may cause an incorrect dose measurement.

Other tips:

  • Take Kaletra doses precisely as prescribed.
  • Please do not take more, less, or take it more often than prescribed.
  • Continue to take medicine even if you feel well.
  • Do not stop taking without talking to your healthcare provider.
  • If you take doses less than the prescribed or stop taking them at once, your condition may become more challenging to treat.


Store Kaletra tablets at room temperature and protect them from excess moisture. It is best to keep the tablets in the container they came in. Use the tablets within two weeks if you take them out of the original container.

Keep the oral solution in the refrigerator at 36 to 46 degrees Fahrenheit (two to eight degrees Celsius) until the expiration date, or at room temperature for up to two months.

Keep all the medications out of the reach of children and pets, ideally locked in a cabinet or closet. Always keep the safety lock on to avoid accidental poisoning.

If you plan to travel with Kaletra, get familiar with your final destination's regulations. In general, be sure to make a copy of your Kaletra prescription. Try to keep your medication in its original container from your pharmacy with your name on the label. If you have any questions about traveling with your medicine, ask your pharmacist or healthcare provider.

Discard all unused and expired drugs, but do not pour them down the drain or toilet. Ask your pharmacist or healthcare provider about the best ways to dispose of this medicine. And check out drug take-back programs in your area.

Off-Label Uses

Kaletra (lopinavir, boosted with ritonavir) was used off-label to treat COVID-19 during the pandemic. Evidence from clinical trials does not support the use of Kaletra to treat COVID-19.

How Long Does Kaletra Take to Work?

Kaletra is not a cure but a therapy to avoid complications and chances of getting HIV-related infections. It's a long-term treatment and may be required for an extended period. Follow the guidelines of your healthcare provider and take as long as recommended.

What Are the Side Effects of Kaletra?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Kaletra may cause some common side effects:

  • Bloating
  • Diarrhea
  • Difficulty falling asleep or staying asleep
  • Headache
  • Heartburn
  • High cholesterol, high lipids, and high triglycerides
  • Muscle pain
  • Numbness or tingling in the hands or feet
  • Nausea and vomiting
  • Stomach pain
  • Weight loss

Call your healthcare provider if any of these symptoms worsen or do not go away.

Severe Side Effects

Contact your healthcare provider right away if you develop any signs of a severe reaction. Call 911 if your symptoms feel life-threatening.

Serious side effects and their symptoms include:

  • Extreme tiredness
  • Loss of appetite
  • Pain in the upper right part of the stomach
  • Yellowing of the skin or eyes
  • Nausea
  • Vomiting
  • Stomach pain
  • Itchy skin
  • Dizziness
  • Lightheadedness
  • Fainting
  • Irregular heartbeat
  • Blisters
  • Rash

Report Side Effects

Kaletra may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Kaletra Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For treatment of HIV infection:
    • For oral dosage form (solution):
      • Adults—400 milligrams (mg) of lopinavir and 100 mg of ritonavir (5 milliliters [mL]) two times a day with food or 800 mg of lopinavir and 200 mg of ritonavir (10 mL) once a day with food. Your doctor may adjust your dose as needed.
      • Children 6 months and older—Dose is based on body weight or body size and must be determined by your child's doctor. The recommended dose is 10 to 12 milligrams per kilogram (mg/kg) of body weight or 230 milligrams per square meter (mg/m[2]) of body size for lopinavir and 2.5 to 3 mg/kg or 57.5 (mg/m[2]) for ritonavir two times a day with food. Your doctor may adjust your dose as needed.
      • Children 14 days to 6 months of age—Dose is based on body weight or body size and must be determined by your child's doctor. The recommended dose is 16 milligrams per kilogram (mg/kg) of body weight or 300 milligrams per square meter (mg/m[2]) of body size for lopinavir and 4 mg/kg or 75 (mg/m[2]) for ritonavir two times a day with food.
      • Children younger than 14 days of age—Use is not recommended, unless your doctor determines it is safe to be given.
    • For oral dosage form (tablets):
      • Adults—400 milligrams (mg) of lopinavir and 100 mg of ritonavir (2 tablets) two times a day or 800 mg of lopinavir and 200 mg of ritonavir (4 tablets) once a day. Your doctor may adjust your dose as needed.
      • Children 6 months and older—The child must be able to swallow a tablet whole. Dose is based on body weight and must be determined by your child's doctor. The recommended dose is 200 to 400 milligrams (mg) of lopinavir and 50 to 100 mg of ritonavir (2 to 4 tablets) two times a day. Your doctor may adjust your dose as needed.
      • Children 14 days to 6 months of age—This dosage form is usually not used for infants. Please refer to the oral solution dosage form.
      • Infants younger than 14 days of age—Use is not recommended, unless your doctor determines it is safe to be given.


The following modifications (changes) should be kept in mind when using Kaletra:

Severe allergic reaction: Kaletra should be avoided in people hypersensitive to lopinavir or any tablet or oral solution ingredient. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.

Pregnancy: Discuss with your healthcare provider if you are or plan to become pregnant and weigh the benefits and risks of taking Kaletra during your pregnancy. It should only be used if the potential benefits outweigh the risks.

Breastfeeding: The CDC suggests that people infected with HIV avoid breastfeeding to avoid the risk of giving their babies postnatal HIV-1. Breastfeeding should be avoided while receiving Kaletra to prevent transmitting HIV-1 to their babies and prevent severe adverse reactions in nursing infants.

Adults over 65: Clinical studies haven't included a large enough number of people in this age group to see whether they respond differently from younger adults. In general, caution is advised regarding the greater frequency of hepatic (liver), renal (kidney), and cardiac (heart) diseases and use with other drug therapies. 

Children: The safety and efficacy of Kaletra have not been established in people under 14 days.

Other modifications: Kaletra is metabolized by the liver; therefore, hepatic impairment (liver conditions) can cause a rise in lopinavir concentrations in the body. Caution is required in people with hepatic impairment to avoid side effects. 

Administration modifications: Take the tablets with or without food. But if taking an oral solution, you must take it with food.

Missed Dose

If you accidentally forgot your Kaletra dose, take it as soon as you remember. However, if it's already close to your next scheduled dose, skip the missed dose and take the following dose at your next scheduled dosing time. Don't try to double up to make up for the missed dose.

Try to help yourself remember to keep your appointments and take your medication routinely. If you miss too many doses, Kaletra might be less effective at preventing HIV.

Overdose: What Happens If I Take Too Much Kaletra?

If you have taken an accidental overdose of Kaletra and have life-threatening symptoms, seek immediate medical attention.

If a child drinks more than the prescribed dose of the Kaletra solution, seek immediate medical help. Kaletra solution contains a large amount of alcohol and other ingredients that could be very harmful to a child.

What Happens If I Overdose on Kaletra?

If you think you or someone else may have overdosed on Kaletra, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Kaletra, call 911 immediately.


Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check the progress of you or your child at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Do not use this medicine if you or your child are also using alfuzosin (Uroxatral®), apalutamide (Erleada®), cisapride (Propulsid®), colchicine (Colcrys®), dronedarone (Multaq®), elbasvir/grazoprevir (Zepatier®), ergot medicines (eg, dihydroergotamine, ergotamine, methylergonovine, Cafergot®, Ergomar®, Methergine®, or Migranal®), lomitapide (Juxtapid®), lovastatin (Advicor®, Altoprev®, Mevacor®), lurasidone (Latuda®), oral midazolam (Versed®), pimozide (Orap®), ranolazine (Ranexa®), rifampin (Rifadin®), sildenafil (Revatio®), simvastatin (Simcor®, Vytorin®, Zocor®), or triazolam (Halcion®).

Pancreatitis may occur while you are using this medicine. Check with your doctor right away if you or your child have sudden and severe stomach pain, chills, constipation, nausea, vomiting, fever, or lightheadedness.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

This medicine may increase blood sugar levels. Check with your doctor if you or your child notice a change in the results of your blood or urine sugar tests.

This medicine may cause heart rhythm problems, including PR or QT prolongation. It may change the way your heart beats and cause fainting or serious side effects in some patients. Contact your doctor right away if you or your child have any symptoms of heart rhythm problems, such as fast, pounding, or irregular heartbeats.

This medicine may increase the amount of cholesterol and fats in your blood. If this condition occurs, your doctor may give you some medicines that can lower the amount of cholesterol and fats in the blood. Talk to your doctor if you or your child have concerns.

If you or your child develop a skin rash, hives, or any allergic reaction to this medicine, check with your doctor as soon as possible.

If you are taking the oral liquid, you should limit the amount of alcohol you drink. The Kaletra® oral liquid contains 42% alcohol. Talk to your doctor if you or your child are taking, or plan to take, metronidazole (Flagyl®) or disulfiram (Antabuse®).

Birth control pills that contain estrogen may not work as well while you are using this medicine. To keep from getting pregnant, use an additional form of birth control along with your pills. Other forms of birth control include condoms, a diaphragm, or contraceptive foam or jelly.

Your immune system may get stronger when you start taking HIV medicines. Tell your doctor right away if you notice any changes in your health. Sometimes the immune system will start to fight infections that were hidden in your body, such as pneumonia or tuberculosis, or may result in a flare-up of a hidden autoimmune disorder such as Graves disease, polymyositis, or Guillain-Barré syndrome.

This medicine may cause you to have excess body fat. Tell your doctor if you or your child notice changes in your body shape, such as an increased amount of fat in the upper back and neck, or around the chest and stomach area. You might also lose fat from the legs, arms, and face.

This medicine may increase the risk of bleeding in patients with hemophilia (a bleeding disorder). Talk with your doctor about this risk.

This medicine will not keep you from giving HIV to your partner during sex. Make sure you understand this and practice safe sex, even if your partner also has HIV, by using a latex condom or other barrier method. This medicine will also not keep you from giving HIV to other people if they are exposed to your blood. Do not re-use or share needles with anyone.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription and nonprescription (over-the-counter [OTC]) medicines, and herbal (eg, St. John's wort) or vitamin supplements.

What Are Reasons I Shouldn’t Take Kaletra?

Kaletra shouldn't be used with certain conditions and with certain medications. Avoid using Kalerta in people who are hypersensitive (allergic) to any of its ingredients. Hypersensitivity reactions include: 

Kaletra shouldn't be used with drugs that are metabolized by the liver enzyme CYP3A4. Taking these together can increase concentrations of the drugs in the body. This can cause life-threatening reactions. 

Kaletra also shouldn't be used with drugs that are potent CYP3A4 inducers. Taking these together can reduce lopinavir concentrations in the body, making Kaletra less effective and also increasing the potential for drug resistance.

Certain drugs are contraindicated with Kaletra. These drugs, when taken with lopinavir, can cause severe side effects such as:

  • Cardiac arrhythmias (irregular heart rate)
  • Increased plasma concentration of drugs leading to adverse effects
  • A decrease in Kaletra's ability to fight the HIV virus

The following drugs are contraindicated with Kaletra:

Alpha 1­ Adrenoreceptor Antagonists

  • Uroxatral (alfuzosin) 


  • Multaq (dronedarone)

Anti-gout medications

  •  Mitigare (colchicine)


  • Rifampin


  • Latuda (lurasidone)
  • Orap (pimozide)

Ergot Derivatives

  • D.H.E. 45 (dihydroergotamine)
  • Ergomar (ergotamine)
  • Methergine (methylergonovine)

GI Motility Agent

  • Propulsid (cisapride)

Hepatitis C Direct-Acting Antivirals

  •  Zepatier (elbasvir/grazoprevir)

Herbal Products 

  • St. John's Wort 

 HMG-CoA Reductase Inhibitors 

  • Altoprev (lovastatin)
  • Zocor (simvastatin)

PDE5 Inhibitor

  • Viagra (sildenafil)


  • Halcion (triazolam)

What Other Medications Interact With Kaletra?

Most of the following drug interactions can result in certain life-threatening situations, such as cardiac arrhythmias (changes in heart rhythm) and changes in concentration of different drugs in the body, which can cause adverse effects. Always consult your pharmacist or healthcare provider before taking any medication with Kaletra. Use caution when taking Kaletra with the following medications:

Anticancer drugs:

  • Vincristine
  • Vinblastine
  • Sprycel (dasatinib)
  • Tasigna (nilotinib)


  • Lidocaine (systemic)
  • Nexterone (amiodarone)
  • Tikosyn (dofetilide)
  • Rhythmol (propafenone)
  • Quinidine



  • Carbamazepine
  • Phenobarbital
  • Phenytoin
  • Valproate



  • Biaxin (clarithromycin)


  • Mitigare (colchicine)


  • Ketoconazole
  • Onmel (itraconazole)*
  • Vfend (voriconazole)


  • Mycobutin (rifabutin)
  • Sirturo (bedaquiline)


  • Mepron (atovaquone)


  • Seroquel (quetiapine)


  • Xanax (alprazolam)
  • Tranxene (clorazepate)
  • Valium (diazepam)
  • Flurazepam
  • Intravenously administered midazolam

Calcium channel blockers:


Endothelin receptor antagonists:

  • Tracleer (bosentan) 

HMG-CoA reductase inhibitors:

Hepatitis C direct-acting acting antivirals:

  • Victrelis (boceprevir)
  • Olysio (simeprevir)
  • Viekira Pak (ombitasvir/paritaprevir/ritonavir and dasabuvir)

HIV protease inhibitors:

  • Atazanavir
  • Crixivan (indinavir)
  • Kaletra (lopinavir/ritonavir)
  • Aptivus (tipranavir/ritonavir)


Inhaled or intranasal steroids:

  • Flonase (fluticasone)
  • Pulmicort (budesonide)

Long-acting beta-adrenoceptor agonists:

  • Serevent (salmeterol)

Narcotic analgesics:

  • Methadose (methadone)
  • Abstral (fentanyl)

Nucleoside reverse transcriptase inhibitors:

  • Videx (didanosine)
  • Ziagen (abacavir )
  • Retrovir (zidovudine)

Non-nucleoside reverse transcriptase inhibitors:

  • Rescriptor (delavirdine) 
  • Sustiva (efavirenz)
  • Viramune (nevirapine)

Oral contraceptives:

PDE5 inhibitors (phosphodiesterase type 5 inhibitors):


  • Parenterally (by injection) administered midazolam

This may not be a complete list of drugs, and others can cause drug-drug interactions. Keep a list of all the medicines you take and consult with your healthcare provider. Talk with your pharmacist or healthcare provider for more detailed information about medication interactions with Kaletra.

And be sure to talk with your healthcare provider about any other medicines you take or plan to take, including over-the-counter, nonprescription products, vitamins, herbs, or plant-based medicines.

What Medications Are Similar?

The FDA approved drugs under the class of HIV protease inhibitors (PIs) include:

  • Invirase (saquinavir) was developed by F. Hoffmann-La Roche Ltd (Basel, Switzerland). Invirase was the first FDA-approved HIV protease inhibitor in 1995. 
  • Norvir (ritonavir) was approved by the FDA in 1996. It boosts the circulating concentration of other HIV protease inhibitors by inhibiting cytochrome P450 3A4 (a liver enzyme). 
  • Crixivan (indinavir) was developed by Merck & Co, Inc. (Whitehouse Station, NJ, USA) and approved in 1996.
  • Viracept (nelfinavir) was developed by Agouron Pharmaceuticals (Pfizer, Inc., New York, NY, USA) and approved in 1997.
  • Reyataz (atazanavir) is an aza-dipeptide analog with potent anti-HIV activity and was approved in 2003.
  • Lexiva (fosamprenavir), developed by GlaxoSmithKline plc (Brentford, UK), was approved by the FDA in 2003.
  • Aptivus (tipranavir) is the only non-peptidomimetic HIV protease inhibitor approved by FDA in 2005.
  • Prezista (darunavir) Darunavir approved in 2006, is the latest HIV protease inhibitor on the market.

Some brands are used as combination drugs like Kaletra, combining two or more antiviral therapy drugs from different classes into a single tablet. These FDA-approved combination protease inhibitors include:

  • Prezcobix (cobicistat/darunavir)
  • Evotaz (atazanavir/cobicistat)

Using other HIV protease inhibitors with Kaletra should be avoided as it could cause life-threatening interactions. Always take the prescribed brand as directed and don't switch between brands.

Frequently Asked Questions

  • What is Kaletra?

    Kaletra is a combination drug containing lopinavir and ritanovir. The FDA approved it to treat HIV infections in adults and children above 14 days old. Kaletra is used with other antiviral drugs. 

  • Does Kaletra cure HIV/AIDS?

    Kaletra does not cure HIV, but it may decrease the risk of developing acquired immunodeficiency syndrome (AIDS) and HIV-related diseases, including serious infections or cancer. Always practice safer sex and make other lifestyle changes to avoid the risk of transmitting HIV to other people.

  • What are the side effects of Kaletra?

    Kaletra may have side effects such as diarrhea, nausea, vomiting, stomach upset, inflammation of the pancreas, bloating, headache, difficulty falling asleep, loss of appetite, itchy skin, irregular heartbeat, etc. If any of these side effects get worse, call your healthcare provider. 

  • What is the best way to take Kaletra?

    You can take Kaletra tablets with or without food. However, if you take an oral solution, you must take it with food.

  • Does Kaletra affect my ability to drive or operate machinery?

    Kaletra's effects on the ability to drive or operate machinery haven't been tested. It's better not to drive a car or operate machinery until you know how it affects you (causing nausea, dizziness, or headache).

How Can I Stay Healthy While Taking Kaletra?

Protease inhibitors, including Kaletra, play a significant role in HIV-related infections such as AIDS. Although these medications are not a cure, they help reduce the complications of the disease. However, side effects and specific drug interactions are common disadvantages of these medicines. Your healthcare provider will prescribe the most suitable medication, depending on your need and clinical condition. Refer below for some general tips to support your health:

  • Take HIV infection-related medications as recommended by your healthcare provider.
  • Practice safer sex and avoid using contaminated syringes, razors, and other personal items to prevent transmission of infection.
  • Achieve and maintain a healthy weight to prevent a worsening condition.
  • Consider support groups or working with a healthcare provider to help you find coping strategies and help you avoid transmitting the infection to others.
  • Always take medicine regularly as prescribed to get the maximum therapeutic effect.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. Kaletra (lopinavir and ritonavir) label.

  2. Lv Z, Chu Y, Wang Y. HIV protease inhibitors: a review of molecular selectivity and toxicity. HIV AIDS (Auckl). 2015;7:95-104. doi:10.2147/HIV.S79956

  3. Croxtall JD, Perry CM. Lopinavir/Ritonavir: a review of its use in the management of HIV-1 infection. Drugs. 2010;70(14):1885-1915. doi:10.2165/11204950-000000000-00000

  4. Centers for Disease Control and Prevention. Statistics overview: HIV/AIDS.

  5. Dorward J, Gbinigie O, Cai T, et al. The protease inhibitor lopinavir, boosted with ritonavir, as treatment for COVID-19: a rapid review. Antivir Ther. 2020;25(7):365-376. doi:10.3851/IMP3385.