Lamotrigine and Lopinavir and ritonavir interaction
Lamotrigine and Lopinavir and ritonavir: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Lamotrigine (SUBVENITE) label · effective 2026-06-04
Lopinavir/ritonavir ↓ lamotrigine Decreased lamotrigine concentration approximately 50%.
Atazanavir/ritonavir ↓ lamotrigine Decreased lamotrigine AUC approximately 32%.
Protease inhibitors lopinavir/ritonavir and atazanavir/lopinavir decrease lamotrigine exposure by approximately 50% and 32%, respectively.
From the Lopinavir and ritonavir (Kaletra) label · effective 2026-07-23
Anticonvulsants: carbamazepine, phenobarbital, phenytoin ↓ lopinavir ↓ phenytoin KALETRA may be less effective due to decreased lopinavir plasma concentrations in patients taking these agents concomitantly and should be used with caution.
Anticonvulsants: lamotrigine, valproate ↓ lamotrigine ↓ or ↔ valproate A dose increase of lamotrigine or valproate may be needed when co-administered with KALETRA and therapeutic concentration monitoring for lamotrigine may be indicated; particularly during dosage adjustments.
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.