Ethosuximide - Zonisamide (5)

6-10/20

Ethosuximide

Reduces low threshold Ca Currents!!

Primarily used in ABSENCE SEIZURES, not effective for Tonic-Clonic

Ethosuximide AE

• GI complaints

• Drowsiness, dizziness, headache

• Rash → SJS!!!!

• Bone marrow depression

NTI: 40-100 mcg/mL

Oxcarbazepine (Oxtellar XR, Trileptal)

Indicated for monotherapy and adjunctive therapy of partial seizures in adults and children 

Oxcarbazepine Antiseizure effects

Voltage-sensitive sodium channels in neuronal membranes blocked, hyperexitable neurons stabilized, and seizures suppressed

Oxcarbazepine AE

• Dizziness

• Drowsiness

• Double vision

• Nystagmus

• Headache

• N/V

• Ataxia

• SJS + RAsh

• Toxic epidermal necrolysis

• Drug interactions

• Clinically Significant Hyponatremia: Na+ below 125 mmol/L

Lamotrigine (Lamictal)

• Use

  • Broad spectrum antisiezure activity

  • Bipolar disorder

Lamotrigine AE

• Dizziness

• Diplopia

• Blurred vision

• N/V

• Headache

• Severe skin reactions: RASH lead to SJS

• Idiosyncratic and related to dose escalating too fast!! Over 6-8 weeks!

• Aseptic meningitis

• Risk for SUICIDE

Lamotrigine Drug Interactions

Valproic Acid

VA inhibits Lamotrigine, Lamotrigine increases rapidly!!! Lower Lamotrigine!!

Gabapentin (Neurontin)

Structurally similar to GABA

• May promote GABA release

• Active in PARTIAL AND GENERALIZED TONIC-CLONIC seizures/Focal

  • Not for epilepsy, most for neuropathic/phantom pain

• Well tolerated

Gabapentin SE

• Dizziness

Take 3x per days and can cause:

• Ataxia

• Fatigue can occur

Zonisamide (Zonegran)

Approved for PARTIAL seizures in adults

• Inhibits the T-type Ca++ currents

• Prolongs voltage gates Na+ Currents similar to phenytoin

• USEFUL IN ABSENCE

Zonisamide AE

• Depression

• Rash

• Psychomotor slowing

• Paresthesia

• Kidney stones

• Dyscrasias

• Hyperthermia (associated with decreased perspiration, or reduced sweat)

• Metabolic acidosis