Table 1.
Mechanisms of action of RTG compared with those of other AEDs: VPA, LTG, TPM, OXC, CBZ, TGB, VGB, and GBP
| AEDs | Enhancement of GABA-mediated inhibition | Inhibition of glutamate excitation | Blockade of calcium channels | Blockade of sodium channels | Enhancement of potassium currents |
|---|---|---|---|---|---|
| RTG | + | NE | NE | NE | + |
| VPA | +/− | + | + (T-type) | +/− | NE |
| LTG | NE | + | + (N, P/Q, R, T) | + | NE |
| TPM | + | + | + (L) | + | NE |
| OXC | NE | NE | + (N, P) | + | NE |
| CBZ | NE | NE | + (L) | + | NE |
| TGB | + | NE | NE | NE | NE |
| VGB | + | NE | NE | NE | NE |
| GBP | + | NE | + (N, P/Q) | NE | NE |
Notes: +, well documented mechanism of action; NE, not effective at therapeutic AED concentrations; +/−, controversial results. Data are from Czuczwar and Patsalos,1 Czapinski et al,2 Sitges et al,6 Sitges et al,7 and Perucca.9
Abbreviations: AED, antiepileptic drug; CBZ, carbamazepine; GABA, γ-amino butyric acid; GBP, gabapentin; LTG, lamotrigine; OXC, oxcarbazepine; RTG, retigabine; TGB, tiagabine; TPM, topiramate; VGB, vigabatrin; VPA, valproate.