An HIV protease inhibitor, combined with ritonavir (Kaletra)
Lopinavir
An HIV protease inhibitor, always combined with ritonavir (as Kaletra), used as part of combination treatment for HIV.
What is Lopinavir?
Lopinavir is an HIV protease inhibitor used to treat HIV. It is always given together with a small amount of ritonavir, which boosts its levels, in the combined product Kaletra, and it is taken as one part of a combination of HIV medicines. It works by blocking an enzyme (protease) the virus needs to make copies of itself. Its most important practical issue is the large number of drug interactions, because it strongly affects how other medicines are handled. It commonly causes diarrhoea and can raise blood fats (lipids) and blood sugar, cause pancreatitis, and affect the heart's PR and QT intervals.
Education and reference only. This is a plain-language guide to Lopinavir — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Lopinavir is an antiretroviral medicine for HIV from the group called protease inhibitors. It is never used on its own: it is always combined with a small dose of ritonavir, which boosts and steadies its levels, in a product known as Kaletra, and it is taken together with other HIV medicines as part of combination antiretroviral therapy. HIV treatment works by using several medicines together to keep the virus suppressed. Lopinavir is taken by mouth, usually as tablets or a liquid, under the care of an HIV specialist team.
How it works
HIV needs an enzyme called protease to cut up newly made viral proteins so it can assemble fresh copies of itself. Lopinavir blocks this protease, so the virus cannot mature and make infectious new particles. The ritonavir it is combined with slows down how quickly the body breaks lopinavir down, keeping useful levels in the blood. Used alongside other HIV medicines that attack the virus in different ways, it helps keep the amount of virus very low, which protects the immune system and reduces the risk of passing HIV on.
Company & origin
Originated / developed by: Specialist manufacturers.
An HIV medicine used in the UK as part of combination treatment, always given together with ritonavir in the product Kaletra.
Practical use
How to take Lopinavir
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it every day exactly as prescribed, as part of your combination of HIV medicines, without missing doses.
- Always give a full list of all your medicines, including over-the-counter and herbal products such as St John's wort, and check before starting anything new.
- Tell your team if you get severe or lasting diarrhoea, as it is the most common side effect.
- Report severe tummy pain promptly, as it can rarely cause inflammation of the pancreas.
- Take it as advised regarding food, and keep all monitoring appointments for blood fats, sugar and other checks.
Weighing it up
Advantages & disadvantages of Lopinavir
Advantages
- An effective part of combination treatment that helps keep HIV under control.
- Boosting with ritonavir keeps steady levels in the blood and adds a barrier against resistance.
- A well-established option taken by mouth as part of HIV therapy.
Disadvantages
- Interacts with a very large number of other medicines, some of which cannot be taken with it.
- Commonly causes diarrhoea, and can raise blood fats and blood sugar over time.
- Can cause pancreatitis and affect the heart's PR and QT intervals.
Practical use
Good to know
The single most important practical point with lopinavir is drug interactions: because it strongly affects the enzymes that handle many other medicines, it can dangerously raise or lower the levels of a long list of drugs, and some must not be taken with it at all, so always give a full medicines list, including anything bought over the counter or any herbal products such as St John's wort, and check before starting anything new. The most common side effect is diarrhoea, which can be troublesome. Over time it can raise blood fats (lipids) and blood sugar and contribute to changes in body fat, and it can occasionally cause inflammation of the pancreas (pancreatitis), so report severe tummy pain. It can also affect the heart's electrical timing (the PR and QT intervals), so heart conditions and other heart-affecting medicines matter. It is taken consistently every day as part of combination therapy under specialist care.
Who should not take it / use with caution
- People who have had a serious allergic reaction to lopinavir or ritonavir should not take it.
- It must not be taken with certain medicines that dangerously interact with it, which the specialist team will check.
- It is used with caution in people with liver problems, pancreatitis, certain heart-rhythm conditions or raised blood fats.
Monitoring
- Regular checks of the amount of virus in the blood and the immune cell counts.
- Blood tests for blood fats (lipids), blood sugar and liver function over time.
- Reviewing all medicines for interactions and watching for heart-rhythm and pancreas effects.
Side effects
- Diarrhoea, nausea and stomach upset.
- Raised blood fats (lipids) and blood sugar, and changes in body fat over time.
- Inflammation of the pancreas (pancreatitis), which can cause severe tummy pain.
- Effects on the heart's electrical timing (the PR and QT intervals) and, occasionally, liver blood test changes.
Key interactions
- It interacts with a very large number of medicines, raising or lowering their levels, so a full medicines list is essential.
- Some medicines, and the herbal product St John's wort, must not be taken with it at all.
- Medicines that affect the heart's rhythm should be reviewed, as lopinavir can affect the PR and QT intervals.
Available as: Tablets and an oral liquid taken by mouth, always combining lopinavir with ritonavir.
Answers
Lopinavir: frequently asked questions
What is lopinavir used for?
It is an HIV protease inhibitor used as part of combination treatment for HIV, always given together with ritonavir in the product Kaletra.
Why is it always given with ritonavir?
Ritonavir slows down how quickly the body breaks lopinavir down, boosting and steadying its levels so it works effectively, which is why they are combined as Kaletra.
Why do interactions matter so much?
Lopinavir strongly affects how many other medicines are handled, so it can raise or lower their levels dangerously; always share a full medicines list and check before starting anything new.
Why does it cause diarrhoea?
Diarrhoea is the most common side effect of lopinavir; tell your team if it is severe or lasting, as there may be ways to help manage it.
Does it affect blood fats or the pancreas?
Over time it can raise blood fats and blood sugar, and it can occasionally cause inflammation of the pancreas, so report severe tummy pain and keep up your blood tests.
The wider class
About HIV protease inhibitor (always boosted with ritonavir)
Lopinavir belongs to the hiv protease inhibitor (always boosted with ritonavir) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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