**5.6 Oxcarbazepine**

Oxcarbazepine is a derivative of carbamazepine, approved as an antiepileptic drug in America in 2000 [63]. This drug is used in the treatment of any type of epileptic seizure. The cellular mechanism by which it exerts its antiepileptic effects is based on the fact that it blocks voltage-gated Na+ channels, modulates the activity of Ca2+ channels, and increases K+ conductance, which consequently produces a stabilization of hyperexcited neuronal membranes for epileptic seizures [64]. Oxcarbazepine is a drug that is metabolized like other antiepileptic drugs by the liver and excreted by the kidney [65]. Toxic effects when daily doses are above 30 mg/kg are basically characterized by gastric alterations: mainly nausea and vomiting. The alterations in the CNS are identified by headache, fatigue, drowsiness, and ataxia. It has also been reported that some patients may have vertigo and hyponatremia [66].

### **5.7 Ethosuximide**

Ethosuximide is an anticonvulsant used to reduce the frequency of absence-type seizures. It exerts its mechanism by reducing Ca2+ currents antagonized by the T-type Ca2+ channels. Furthermore, linked to this drug, modulation of the function of voltage-activated Na+ channels and Na+ /K+ dendritic hyperpolarization-activated cyclic nucleotide-gated channel 1 channels has been suggested. It also reduces neuronal excitability by inhibiting the Na+ /K+ pump [67]. However, ethosuximide is almost entirely absorbed in the digestive tract and metabolized in the liver, which can cause liver disease. The toxic effects of patients who consume above 25 mg/kg comprise gastric issues, nausea, vomiting, constipation, a state of sedation, headache, decreased alertness, drowsiness, and even comas have been reported at the CNS level [68]. Other adverse effects may include weight loss, as well as leukopenia [69].

### **5.8 Gabapentin**

Gabapentin acts mainly by inhibiting partial and generalized seizures. Its mechanism of action is based on enhancing the inhibitory action of GABA [70]. A dose above 1,500 mg of gabapentin can cause hepatotoxicity, additionally, coupling various toxic effects like headaches, diplopia, nystagmus, diplopia, even involuntary movements have been described at the CNS level [71].

### **5.9 Topiramate**

Topiramate is a drug used as an antiepileptic drug that acts by inhibiting partial and generalized seizures. Its action mechanism is exerted by blocking Na+ channels. As an AMPA receptor antagonist, it reduces excitatory neurotransmission, in addition to enhancing the inhibitory action of GABA [72]. Topiramate taken at a dose above 50 mg produces toxic effects, including dizziness. At the CNS level, patients have headaches, drowsiness, decreased concentration, and even confusion. Nevertheless, other anomalies have also been reported [73].
