| Expected changes in plasma concentrations when an AED is added to a pre-existing regimen | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AED added | PB | PHT | PRM | ETS | CBZ | VPA | OXC | LTG | GBP | TPM | TGB | LEV | ZNS | VGB | FBM |
| PB | - | PHT ↑↓ | NCCP | ETS ↓↓ | CBZ ↓↓ | VPA ↓↓ | H-OXC ↓ | LTG ↓↓ | ↔ | TPM ↓↓ | TGB ↓↓ | ↔ | ZNS ↓↓ | ↔ | FBM ↓↓ |
| PHT | PB ↑ | - | PRM ↓ PB ↑ | ETS ↓↓ | CBZ ↓↓ | VPA ↓↓ | H-OXC ↓ | LTG ↓↓ | ↔ | TPM ↓↓ | TGB ↓↓ | ↔ | ZNS ↓↓ | ↔ | FBM ↓↓ |
| PRM | NCCP | PHT ↑↓ | - | ETS ↓↓ | CBZ ↓↓ | VPA ↓↓ | ? | LTG ↓↓ | ↔ | TPM ↓↓ | TGB ↓↓ | ↔ | ZNS ↓↓ | ↔ | FBM ↓↓ |
| ETS | ↔ | ↔ | NE | - | ↔ | VPA ↓ | NE | NE | NE | NE | NE | NE | NE | NE | NE |
| CBZ | ↔ | PHT I↓ | PRM ↓ PB ↑ | ETS ↓↓ | - | VPA ↓↓ | H-OXC ↓ | LTG ↓↓ | ↔ | TPM ↓↓ | TGB ↓↓ | ↔ | ZNS ↓↓ | NE | FBM ↓↓ |
| VPA | PB ↑↑ | PHT ↓* | PB ↑↑ | ETS I↓ | CBZ-E ↑ | - | ↔ | LTG ↑↑ | ↔ | TPM ↓ | EE | ↔ | ↔ | NE | ↔ |
| OXC | PB ↑ | PHT ↑ | ? | ? | CBZ ↓ | ↔ | - | LTG ↓ | NE | ? | ? | NE | ? | NE | ? |
| LTG | ↔ | ↔ | NE | NE | ↔ | ↔ | NE | - | NE | NE | NE | ↔ | ↔ | NE | NE |
| GBP | ↔ | ↔ | NE | NE | ↔ | ↔ | NE | NE | - | NE | NE | ↔ | NE | NE | NE |
| TBP | ↔ | PHT ↑ | ↔ | NE | ↔ | VPA ↓ | ? | ? | NE | - | ? | NE | ? | NE | ? |
| TGB | ↔ | ↔ | ↔ | NE | ↔ | ↔ | NE | NE | NE | NE | - | NE | NE | NE | NE |
| LEV | ↔ | ↔ | ↔ | NE | ↔ | ↔ | NE | ↔ | ↔ | NE | NE | - | NE | NE | NE |
| ZNS | ↔ | ↔ | NE | NE | CBA ↑↓ | ↔ | ? | ↔ | NE | NE | NE | NE | - | NE | ? |
| VGB | PB ↓ | PHT ↓ | PRM ↓ PB ↓ | NE | CBZ ↑ | ↔ | NE | NE | NE | NE | NE | NE | NE | - | NE |
| FBM | PB ↑↑ | PHT ↑↑ | ? | ? | CBZ ↓ CBZ-E ↑ | VPA ↑↑ | ↔ | ↔ | NE | ? | ? | NE | ? | ↔ | - |
PB = Phenobarbital; PHT = phenytoin; PRM = Primidone; ETS = Ethosuximide; CBZ = Carbamazepine; VPA = Valproic acid; OXC = Oxcarbazepine; LTG = Lamotrigine
GBP = Gabapentin; TPM = Topiramate; TGB = Tiagabine; LEV = Levetiracetam; ZNS = Zonisamide; VGB = Vigabatrin; FBM = felbamate H-OXO = 10-hydroxy-oxcarbazepine(active metabolite of OXC); CBZ-E = Cabamazepine 10,11 epoxide NE = None Expected; * Free (pharmacologically active) concentration may increase; NCCP = not commonly coprescribed; ↔ = No change; ↓ = a minor (or inconsistent) decrease in plasma concentration; ↓↓ = a clinically significant decrease in plasma concentration; ↑ = a minor (or inconsistent) increase in plasma concentration; ↑↑ = a clinically significant increase in plasma concentration.
source:Patsalos PN, Perucca E (2003) Clinically important drug interactions in epilepsy: general features and interactions between antiepileptic drugs. Lancet Neurol 2 (6):347-56. DOI: 10.1016/s1474-4422(03)00409-5 PMID: 12849151
Cite this: ICNApedia contributors.Antiseizure medication interactions. ICNApedia, The Child Neurology Knowledge Environment. 24 November 2024. Available at: https://icnapedia.org/knowledgebase/articles/antiseizure-medication-interactions Accessed 24 November 2024.
