When you hear lopinavir/ritonavir, a fixed-dose combination antiretroviral drug used to treat HIV infection. Also known as Kaletra, it combines two drugs that work together to block HIV from copying itself inside the body. This combo isn’t new, but it’s still used today—especially in places where newer meds aren’t available or when resistance to other drugs shows up.
It’s a protease inhibitor, a type of HIV drug that stops the virus from cutting its proteins into usable pieces. Lopinavir does the main job, but it needs help. That’s where ritonavir, a booster drug that slows down how fast your body breaks down lopinavir comes in. Without ritonavir, lopinavir would be cleared too quickly to work. This trick—called pharmacokinetic boosting—is used in several HIV regimens today.
People taking this combo often deal with stomach issues like nausea, diarrhea, or bloating. Some notice changes in fat distribution—loss in the face or arms, gain around the belly. It can also raise cholesterol and blood sugar, so regular blood tests are a must. And yes, it plays well with almost nothing. Mixing it with certain heart meds, sedatives, or even St. John’s wort can be dangerous. That’s why doctors always check your full list of medicines before starting it.
It’s not the first choice anymore. Newer drugs like dolutegravir or bictegravir are simpler, safer, and work better for most people. But lopinavir/ritonavir still has its place—especially in pregnant women, kids, or when resistance limits options. It’s also used in some parts of the world because it’s cheaper and more stable without refrigeration.
What you’ll find in the posts below isn’t just about this one drug. It’s about how medications like this fit into real-life care: how they interact with other pills, how side effects show up, how patients manage long-term use, and why doctors still turn to older drugs when newer ones won’t work. You’ll see how drug allergies, liver health, and even travel rules connect to treatments like this. This isn’t theory. It’s what people actually deal with every day.
Lopinavir/ritonavir boosts HIV treatment by blocking CYP3A4, but this creates dangerous interactions with common drugs like statins, blood thinners, and sedatives. Know the risks before prescribing or taking it.