Carbamazepine

Carbamazepine

Drug monograph · NCLEX study reference
Trade names	Tegretol
Therapeutic class	Anticonvulsant, mood stabilizer
Pharmacologic class	Sodium channel blocker
Onset / peak / duration	Effect over days; autoinduces its own metabolism early.
Half-life / level	Half-life initially 25 to 65 hours then shorter; therapeutic level 4 to 12 mcg/mL.
Routes	PO (oral)
High-alert (ISMP)	No
Black box warning	Yes (see Safety)
Antidote / reversal	None; supportive care.
Pregnancy / lactation	Teratogenic (neural tube defects); use only if essential.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Carbamazepine (brand name Tegretol) — Anticonvulsant, mood stabilizer; Sodium channel blocker.

Identification

• Therapeutic class: Anticonvulsant, mood stabilizer.
• Pharmacologic class: Sodium channel blocker.

Pharmacology

• Mechanism of action: Blocks sodium channels to reduce repetitive neuronal firing.
• Onset / peak / duration: Effect over days; autoinduces its own metabolism early.
• Half-life / therapeutic level: Half-life initially 25 to 65 hours then shorter; therapeutic level 4 to 12 mcg/mL.

Clinical use

• Indications: Focal and tonic-clonic seizures, trigeminal neuralgia, bipolar disorder.
• Usual dose, route, frequency: 200 mg PO twice daily, titrated; liquid and ER available.
• Maximum dose / adjustments: Titrate to level and response.

Safety

• Contraindications: Bone marrow suppression, MAO inhibitor use, prior hypersensitivity.
• Black box warning: Serious and sometimes fatal dermatologic reactions (Stevens-Johnson syndrome and toxic epidermal necrolysis), strongly linked to the HLA-B*1502 allele (screen patients of Asian ancestry); also aplastic anemia and agranulocytosis.
• Interactions: Many CYP3A4 interactions, oral contraceptives (reduced), warfarin, grapefruit juice (food), other antiepileptics.
• Pregnancy / lactation: Teratogenic (neural tube defects); use only if essential.
• High-alert: No.

Adverse effects

• Common side effects: Dizziness, drowsiness, nausea, diplopia.
• Serious effects to report: Severe rash, blood dyscrasias, hyponatremia, hepatotoxicity.
• Antidote / reversal: None; supportive care.

Nursing process

• Assessment before administration: CBC, sodium, LFTs, HLA-B*1502 in at-risk groups, seizure baseline.
• Interventions during therapy: Monitor for rash and infection signs; check sodium.
• Monitor: Drug level, CBC, sodium, LFTs, seizure frequency.
• Evaluation / expected outcome: Seizure or neuralgia control.

Patient teaching

• Patient teaching: Report rash immediately; use backup contraception; avoid grapefruit.
• Notify provider if: Rash, fever, sore throat, bruising, confusion.
• Administration tips: With food; swallow ER whole; avoid grapefruit.