Lopinavir

Key facts

• Lopinavir is a protease inhibitor used to treat HIV infection. It is never given alone: it is always combined with a low dose of ritonavir (as in the combination tablet Kaletra), which blocks the liver enzyme that would otherwise break lopinavir down too quickly.
• It is taken by mouth, usually twice daily with food, as one part of a multi-drug HIV regimen; missing doses lets the virus develop resistance.
• Because the ritonavir component strongly blocks a major liver enzyme (CYP3A4), lopinavir/ritonavir interacts with many other drugs, some seriously enough to be avoided altogether. Always check every prescription, over-the-counter medicine, and herbal product against this.
• Seek urgent care for yellowing of the skin or eyes, severe abdominal pain, or a fast or irregular heartbeat.

What Lopinavir treats

Lopinavir, combined with ritonavir, treats HIV infection as part of a combination antiretroviral regimen. It is also used to help prevent mother-to-child transmission of HIV during pregnancy. It does not cure HIV and does not treat other viral infections.

How Lopinavir works

HIV needs an enzyme called protease to cut newly made viral proteins into the pieces it needs to assemble new, infectious virus particles. Lopinavir blocks this enzyme, so the virus produces defective, non-infectious particles. The ritonavir given alongside it does not fight HIV directly; instead it blocks the liver enzyme that breaks lopinavir down, keeping lopinavir levels high enough to work.

Before you take it

• Tell your prescriber about every medicine you take. Lopinavir/ritonavir can raise levels of many drugs to dangerous levels, including certain statins, some heart rhythm medicines, some sedatives, ergot medicines, and certain steroids, and some of these combinations must be avoided entirely.
• Rifampicin, some anticonvulsants, and St John's wort can lower lopinavir levels enough to let the virus become resistant.
• Mention any history of liver disease, pancreatitis, diabetes, or heart rhythm problems before starting.
• Take it consistently with food, as directed, since food affects how much is absorbed.

Side effects

Common effects include diarrhea, nausea, headache, and fatigue, especially when starting treatment.

Seek urgent care for:

• Yellowing of the skin or eyes, dark urine, or severe abdominal pain, which can signal liver problems or pancreatitis.
• A fast, slow or irregular heartbeat, or fainting.
• Signs of a severe allergic reaction, such as facial swelling or difficulty breathing.
• Unusual thirst, frequent urination, or high blood sugar.

Safety essentials

• Lopinavir only works at the boosted dose it is prescribed at: never take it without its ritonavir component, and never adjust the dose yourself.
• Review every new medicine, including over-the-counter and herbal products, with a pharmacist before starting it, because ritonavir's effect on liver enzymes makes serious interactions common.
• Routine blood tests for liver function, blood sugar, and cholesterol are usually part of ongoing care, since lopinavir/ritonavir can affect all three.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.