Active Ingredients

Lopinavir – Effect, Application & Risks


Lopinavir is a drug that is used in the therapy of HIV infections and acts as a protease inhibitor. The HIV protease inhibitor is used in combination with AbbVie’s product ritonavir and is known on the market under the trade name Kaletra®. The drug received approval from the relevant EU Commission in 2001.

What is lopinavir?

Lopinavir acts as a protease inhibitor and is used in the treatment of HIV infection. The drug is suitable for treating adults as well as children who are at least two years old or older. The common combination of active ingredients called Kaletra® is approved for adults and children. Clinical studies and tests have shown that lopinavir is more effective than comparable active ingredients.

The medicine Lopinavir is available both in the form of film-coated tablets and as a syrup. In the case of the syrup, it is a fixed combination with the substance ritonavir. This was approved in Switzerland in 2000. From a chemical point of view, lopinavir is a white or yellowish-white powder. This powder is hardly soluble in water.

Pharmacological action

Lopinavir is an HIV protease inhibitor that reduces the processing of viral precursor proteins newly formed by the HIV virus into fully functional enzymes and structural proteins. Through this mechanism of action, the drug inhibits the multiplication of the HI virus.

Due to the cytochrome P450 system, the substance lopinavir is metabolized by the human body in a relatively short time. If lopinavir is administered alone, the possible concentration of the drug in the plasma of the blood would be too low to induce a therapeutic effect. For this reason, the substance is usually used in a fixed combination with ritonavir.

Ritonavir is a medicine that belongs to the same group as lopinavir. Ritonavir acts as a second protease inhibitor in this compound, preventing the degradation mechanism of lopinavir and cytochrome P450 monooxygenases, respectively. This makes it possible for a higher concentration of lopinavir to be present in the organism, which is sufficient for an effective reduction in HIV proteases.

One advantage of this strategy lies in the drastic reduction in the dose for the affected patient, so that significantly fewer tablets have to be consumed.

Basically, lopinavir is rapidly broken down by the cytochrome system in the liver . The speed of this hepatic breakdown of the active substance is greatly slowed down by the additional administration of the HIV protease inhibitor ritonavir. This allows the lopinavir to last longer.

Most of the active ingredient binds to proteins in the blood . In addition, a combination with the so-called nucleoside reverse transcriptase inhibitors is also possible.

The lopinavir binds to the viral HIV protease. This is important for the multiplication and spread of the virus . Viral enzymes are curbed by the drug, so that propagation is disrupted. As a result, the viral load for the organism of the affected patient decreases sharply.

Medical Application & Use

The active ingredient lopinavir is used to treat infections with the HIV-1 virus as part of an antiretroviral combination therapy. Lopinavir is an antiviral drug that belongs to the category of so-called HIV protease inhibitors and stops the replication of the HI virus.

The corresponding effects result from the fact that lopinavir reduces the viral protease. This takes on a special meaning and function in the maturation and multiplication of the virus.

As a rule, the drug is taken once or twice a day. The drug is usually administered in the form of film-coated tablets, which are taken either with or without meals. The syrup is to be taken with meals.

Risks & side effects

Numerous unwanted side effects are possible when taking lopinavir . The most common side effects include abdominal pain , diarrhea , vomiting , nausea and a general feeling of weakness . Sweating , skin rashes , headaches and insomnia are also common .

Abnormal stools , flatulence and other gastrointestinal disorders sometimes also occur. Blood tests sometimes show elevated levels of triglycerides and cholesterol . In addition, allergies and reactions of the central nervous system are possible.

Patients who suffer from cardiac arrhythmia , a structural heart disease or a poorly perfused heart are particularly at risk when taking lopinavir.

In addition, interactions with other substances and drugs are possible. The reduction in enzymes in the liver not only increases the concentration of protease inhibitors in the blood, but also that of drugs that are broken down in the same way. These include, for example, antiarrhythmics , benzodiazepines or ergot alkaloids .

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.