HIV Protease Inhibitor (Boosted) — Antiretroviral Therapy Pregnancy: eMC §4.6: lopinavir/ritonavir has been evaluated in over 3000 women during pregnancy, including over 1000 during the first trimester. Post-marketing surveillance through the Antiretroviral Pregnancy Registry has not reported an increased risk of birth defects among over 1000 women exposed during the first trimester, and the prevalence of birth defects after any trimester exposure is comparable to that in the general population. Studies in animals have shown reproductive toxicity, but based on the available data the malformative risk is unlikely in humans and lopinavir can be used during pregnancy if clinically needed. It is not known whether lopinavir is excreted in human milk (it is excreted in rat milk); as a general rule it is recommended that women living with HIV do not breastfeed, in order to avoid transmission of HIV.

Lopinavir / Ritonavir

Brand names: Kaletra

Lopinavir with ritonavir is a co-formulated HIV protease inhibitor combination used as part of antiretroviral therapy for HIV infection.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 5 ml of oral solution (lopinavir 400 mg / ritonavir 100 mg) twice daily, taken with food

Route: Oral - always taken with food; the dose should be administered using a calibrated 2 ml or 5 ml oral dosing syringe best corresponding to the volume prescribed

Frequency: Twice daily

eMC §4.2 (Kaletra (80 mg + 20 mg)/ml oral solution). Should be prescribed by physicians experienced in the treatment of HIV infection. The recommended dosage in adults and adolescents is 5 ml of oral solution (400/100 mg) twice daily with food. TABLET ALTERNATIVE: the adult dose of Kaletra tablets (400/100 mg twice daily) may be used in children weighing 40 kg or more or with a body surface area greater than 1.4 m2; tablets are administered orally and must be swallowed whole and not chewed, broken or crushed - refer to the Kaletra 100 mg/25 mg film-coated tablets SPC. HEPATIC IMPAIRMENT: in HIV-infected patients with mild to moderate hepatic impairment an increase of approximately 30% in lopinavir exposure has been observed but is not expected to be of clinical relevance; there are no data in severe hepatic impairment and Kaletra must not be given to these patients (contraindicated, §4.3). EXCIPIENTS: the total amounts of alcohol and propylene glycol from all medicines, including Kaletra oral solution, given to infants should be taken into account to avoid toxicity from these excipients (§4.4). SAFETY (§4.4): cases of pancreatitis have been reported, including in patients who developed hypertriglyceridaemia; rare increases in PR interval have been reported; increased bleeding including spontaneous skin haematomas and haemarthrosis has been reported in patients with haemophilia A and B treated with protease inhibitors; elevated transaminases with or without elevated bilirubin have been reported as early as 7 days after initiation, so conduct appropriate laboratory testing before starting and monitor closely during treatment. PAEDIATRIC: the SPC gives separate dosing for patients aged from 14 days, based on body weight or body surface area, with different regimens for 14 days to 6 months and for older than 6 months to less than 18 years, and a higher body-surface-area-based dose (with a stated maximum that must not be exceeded) when co-administered with efavirenz or nevirapine - obtain the exact tables from SPC §4.2 and a children's formulary rather than extrapolating from the adult dose. The oral solution is the recommended option for the most accurate dosing in children. Kaletra should not be administered in combination with efavirenz or nevirapine in patients less than 6 months of age, and the oral solution should not be administered to neonates before a postmenstrual age of 42 weeks and a postnatal age of at least 14 days has been reached.

Dose adjustments

Renal

eMC §4.2: since the renal clearance of lopinavir and ritonavir is negligible, increased plasma concentrations are not expected in patients with renal impairment. Because lopinavir and ritonavir are highly protein bound, it is unlikely that they will be significantly removed by haemodialysis or peritoneal dialysis. No numeric dose adjustment is stated.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substances or to any of the excipients (eMC §4.3)
Severe hepatic insufficiency (eMC §4.3)
Co-administration with medicinal products that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events (eMC §4.3), including: alfuzosin; ranolazine; amiodarone and dronedarone; fusidic acid (contraindicated in dermatological infections); neratinib; venetoclax (at dose initiation and during the ramp-up phase); colchicine (in patients with renal and/or hepatic impairment); astemizole and terfenadine; lurasidone; pimozide; quetiapine; ergot alkaloids (dihydroergotamine, ergonovine, ergotamine, methylergonovine); cisapride. The captured §4.3 table is truncated after cisapride - clinician to review the complete contraindicated list in the SPC

Side effects

Diarrhoea, nausea and vomiting - the most common reactions related to Kaletra therapy, typically at the beginning of treatment
Hypertriglyceridaemia and hypercholesterolaemia - common, and may occur later in treatment; also blood glucose disorders including diabetes mellitus, weight decreased and decreased appetite (common)
Pancreatitis - reported in patients receiving Kaletra, including those who developed hypertriglyceridaemia; rare increases in PR interval have been reported
Upper respiratory tract infection (very common); lower respiratory tract infection and skin infections including cellulitis, folliculitis and furuncle (common)
Anaemia, leucopenia, neutropenia and lymphadenopathy (common); hypersensitivity including urticaria and angioedema (common); immune reconstitution inflammatory syndrome (uncommon)
Headache including migraine, neuropathy including peripheral neuropathy, dizziness, insomnia and anxiety (common); cerebrovascular accident, convulsion, dysgeusia, ageusia and tremor (uncommon)

Interactions

Lopinavir and ritonavir are both inhibitors of the CYP3A isoform of P450, so Kaletra should not be co-administered with medicinal products highly dependent on CYP3A for clearance where elevated plasma concentrations are associated with serious and/or life-threatening events (eMC §4.3) - see the contraindications list
Colchicine (eMC §4.3, §4.4) - increased plasma concentrations with potential for serious and/or life-threatening reactions in patients with renal and/or hepatic impairment
Fusidic acid (eMC §4.3) - increased plasma concentrations; concomitant administration is contraindicated in dermatological infections
Concomitant antiviral therapy for hepatitis B or C (eMC §4.4) - patients with chronic hepatitis B or C on combination antiretroviral therapy are at increased risk of severe and potentially fatal hepatic adverse reactions; refer to the relevant product information
The eMC §4.5 interaction section was not captured in this bundle - clinician to review the full interaction table in the SPC (the fetched §4.3 table itself is truncated)

Clinical monograph

How it works

Lopinavir inhibits the HIV protease enzyme, preventing cleavage of viral polyproteins into functional units and producing immature, non-infectious virions; low-dose ritonavir acts as a pharmacokinetic booster by inhibiting CYP3A-mediated metabolism of lopinavir.

Prescribing in practice

The ritonavir-mediated CYP3A inhibition causes numerous and potentially serious drug interactions, so all co-medication must be checked against current prescribing references before and during treatment.
It is associated with metabolic disturbance including dyslipidaemia and effects on glucose, and may prolong the PR and QT intervals in susceptible individuals.
Gastrointestinal upset, particularly diarrhoea, is common and may affect tolerability and adherence.

Monitoring

Monitor HIV viral load and CD4 count alongside lipids and glucose, and review for relevant drug interactions.

Counselling the patient

Take every dose to keep the virus controlled and reduce the risk of resistance.
Always check with your team or pharmacist before starting any new medicine, including over-the-counter products.
Tell your team if you get troublesome diarrhoea or other persistent side effects.

Evidence & guidelines

Boosted protease inhibitors are established components of combination antiretroviral therapy supported by extensive clinical trial experience.

Reference: BHIVA HIV Treatment Guidelines 2019; WHO Consolidated HIV Guidelines 2021; PENTA Paediatric HIV Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways