Introduction

Carbamazepine is chemically similar to the tricyclic antidepressant drugs. It is most commonly used in the treatment of epilepsy, particularly partial seizures, where carbamazepine remains a first-line medication. Other uses include
  • Neuropathic pain (e.g. trigeminal neuralgia, diabetic neuropathy)
  • Bipolar disorder

Mechanism of action

Carbamazepine binds to sodium channels increases their refractory period.

Adverse effects

  • P450 enzyme inducer
  • Dizziness and ataxia
  • Drowsiness
  • Headache
  • Visual disturbances (especially diplopia)
  • Steven-Johnson syndrome
  • Leucopenia and agranulocytosis
  • Hyponatraemia secondary to syndrome of inappropriate ADH secretion

Carbamazepine is known to exhibit autoinduction, hence when patients start carbamazepine they may see a return of seizures after 3-4 weeks of treatment.