Figure 1.

Sequential drug trials in pharmacotherapy of epilepsy. Initial monotherapy is the standard mode of therapy. If it failed, either substitution monotherapy or combination therapy is conducted according to the preference of physicians. During the era of conventional drugs, most epileptologists favored substitution monotherapy and diagnosed drug-resistant epilepsy after the failure of third drug monotherapy. In the era of new AEDs, duotherapy is increasingly undertaken after the failure of initial monotherapy, especially if the first drug was at least partially effective and well tolerable. If the second drug therapy failed, duotherapy is favored. AE, adverse effects; LAEPs, Liverpool Adverse Effect Profiles; GAD-7, Generalized anxiety disorder-7; NDDI-E, neurological disease depression inventories in epilepsy; QOL-31, quality of life-31; →, indicates options in favor; ⇢, suggests less favorable options.