Lopinavir and ritonavir and Posaconazole interaction
Lopinavir and ritonavir and Posaconazole: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Lopinavir and ritonavir (Kaletra) label · effective 2026-07-23
Avoid use in patients with congenital long QT syndrome, those with hypokalemia, and with other drugs that prolong the QT interval.
Potential for KALETRA to Affect Other Drugs Lopinavir/ritonavir is an inhibitor of CYP3A and may increase plasma concentrations of agents that are primarily metabolized by CYP3A.
Although not observed in the KALETRA/ketoconazole drug interaction study, co-administration of KALETRA and other drugs that inhibit CYP3A may increase lopinavir plasma concentrations.
Antifungals: ketoconazole*, itraconazole, voriconazole isavuconazonium sulfate* ↑ ketoconazole ↑ itraconazole ↓ voriconazole ↑ isavuconazonium High doses of ketoconazole (>200 mg/day) or itraconazole (> 200 mg/day) are not recommended.
Alternative antifungal therapies should be considered in these patients.
From the Posaconazole (NOXAFIL) label · effective 2026-02-13
Anti-HIV Drugs that are CYP3A4 Substrates Mechanism and Clinical Effect(s) Ritonavir and atazanavir are CYP3A4 substrates and posaconazole increased plasma concentrations of these drugs [see Clinical Pharmacology (12.3) ].
Prevention or Management Ritonavir and Atazanavir Monitor frequently for adverse reactions and toxicity of ritonavir and atazanavir during concomitant use.
Effects of Noxafil and Noxafil PowderMix on Other Drugs Posaconazole is a strong CYP3A4 inhibitor.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.