Carbamazepine

WHAT IS IT?

Carbamazepine (tegretol) is an anticonvulsant medication that works by increasing sodium channel inactivation. It is also used as a mood stabilizer.

Source
Source
WHEN DO WE USE IT?

Seizures: simple partial seizure, complex partial seizure (first-line for focal seizures)

Other neurological: trigeminal neuralgia (first line)

Psychiatric: bipolar disorder (second line)

WHEN DO WE AVOID USING IT?

Generalized seizures: is believed that this medication can actually make generalized seizures worse.

During pregnancy (teratogenic)

HOW IS IT ADMINISTERED?

This medication is orally administered.

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Source
WHAT ARE THE SIDE EFFECTS/TOXICITY?

Neurological: diplopia, ataxia

Hematological: agranulocytosis, aplastic anemia

Endocrine: SIADH (causing hyponatremia)

Fetal hydantoin syndrome (newborns whose mothers use this drug): mid facial hypoplasia, microcephaly, cleft lip and palate, digital hypoplasia, hirsutism, developmental delay.

Other: Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN), liver toxicity

ANYTHING ELSE TO KEEP IN MIND?

Labs to check in patients on this medication include:

  • BMPevaluating for hyponatremia can help assess for the development of SIADH with medication usage.
  • CBC: this test can evaluate the levels of white blood cells to see if the patient has agranulocytosis.
  • LFTswhile a rare complication, liver function tests can help evaluate for liver toxicity.
  • Carbamazepine serum level: the level of this medicaiton should be measured in the patient’s blood. The therapeutic range is generally in the range of 3-14 µg/mL.

Cytochrome P450 inducer: this medication will activate the activity of these liver enzymes (inducing its own metabolism).

FURTHER READING

DynaMed

UpToDate

 

Page Updated: 06.26.2016