Lopinavir — What it is, how it works, and when it’s used

Lopinavir is an antiviral drug commonly given with ritonavir (brand name Kaletra) to treat HIV. Ritonavir boosts lopinavir levels so the drug works better. Today lopinavir/ritonavir is mainly part of combination therapy for people living with HIV. It was also tested for COVID-19 early in the pandemic, but large trials such as RECOVERY and SOLIDARITY found it didn’t help for COVID-19 patients.

How to take lopinavir/ritonavir

Most adults take lopinavir/ritonavir as a fixed-dose tablet of 400 mg/100 mg twice daily with food. Taking it with a meal improves absorption and cuts down stomach upset. There’s an oral solution too; that needs different handling and sometimes refrigeration. Follow your clinic’s exact dose — doses can change based on other drugs you take, pregnancy, or liver disease. Never split pills unless your pharmacist or doctor says it’s okay.

Side effects, interactions, and monitoring

Common side effects are diarrhea, nausea, and abdominal pain. Over time, lopinavir/ritonavir can raise cholesterol and triglycerides, and it may affect blood sugar. Rare but serious problems include liver injury and pancreatitis. If you have chronic liver disease, your provider will monitor liver tests more often.

Drug interactions are numerous because ritonavir strongly affects the CYP3A4 enzyme. Some drugs are unsafe with lopinavir/ritonavir — for example, simvastatin and certain sedatives. Rifampin and St. John’s wort greatly reduce lopinavir levels and should be avoided. Always tell every clinician and your pharmacist about lopinavir/ritonavir so they can check for interactions.

Before starting, your provider will check baseline liver tests, fasting lipids, and blood sugar. During treatment they’ll repeat those tests periodically and assess how well the HIV is controlled with viral load testing. Don’t stop lopinavir/ritonavir suddenly without medical advice — abrupt stops can let the virus rebound and resistance can develop.

Practical tips: take doses at roughly the same times each day and with a meal. If you miss a dose, follow the instructions from your provider or the medication leaflet — usually take it as soon as you remember unless it’s close to your next dose. Keep a current medication list and a copy of your HIV care plan with you when traveling.

Is it safe in pregnancy? Lopinavir/ritonavir has been used safely in pregnancy in many cases, but dosing and timing may change. If you’re pregnant or planning pregnancy, discuss this with your HIV specialist to get the best regimen for both you and the baby.

If you notice severe belly pain, yellowing skin or eyes, very high fever, or signs of an allergic reaction, seek medical care right away. For routine questions, talk with your HIV clinic, pharmacist, or infectious disease doctor — they’ll help adjust treatment and manage side effects so the medication works well for you.