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{{MedTemplate
{{MedTemplate
| generic           = Carbamazepine
| generic           = Carbamazepine
| brand             = Tegretol
| brand             = Tegretol (IR, XR, suspension), Carbatrol (ER), Equetro (ER for bipolar), Epitol
| structure         =  
| structure         =
| classes           = Mood Stabilizer, Anticonvulsant
| classes           = [[:Category:Anticonvulsants|Anticonvulsant]], [[:Category:Mood stabilizers|Mood stabilizer]], [[:Category:Sodium channel blockers|Sodium channel blocker]]
| mechanism          = Sodium channel blocker
| uses             = <vote slug="partial-seizures-monotherapy-use">Partial-onset and generalized tonic-clonic seizures (FDA)</vote>, <vote slug="trigeminal-neuralgia-use">Trigeminal neuralgia (FDA; the first-line and textbook indication)</vote>, <vote slug="bipolar-mania-mixed-use">Bipolar I mania and mixed episodes (Equetro; FDA)</vote>, <vote slug="neuropathic-pain-broad-use">Neuropathic pain (off-label)</vote>
| uses               =  
| starting_dose     = Seizures: 200 mg PO BID, titrate by 200 mg/week to 800-1200 mg/day. Trigeminal neuralgia: 100-200 mg BID, titrate to 200-400 mg TID. Bipolar: 200 mg BID, titrate to 1600 mg/day
| starting_dose     =  
| preparations     = IR tablets 200 mg; chewable 100 mg; oral suspension 100 mg/5 mL; XR tablets 100, 200, 400 mg (Tegretol XR); ER capsules 100, 200, 300 mg (Carbatrol, Equetro)
| preparations       =  
| fda_max           = 1200 mg/day (adult seizures); 1600 mg/day (bipolar mania)
| fda_max          =  
| pill_id           =
| routes             =  
| routes           = Oral
| onset             =  
| onset             = Anticonvulsant effect within days; trigeminal neuralgia relief 24-72 hours; mood-stabilizing effect over weeks
| duration           =  
| duration         = BID-QID dosing (IR); BID for ER formulations
| halflife           =
| halflife          = '''Autoinduction''': 25-65 hours initially, falling to 12-17 hours after 2-3 weeks of dosing as carbamazepine induces its own CYP3A4 metabolism. Major clinical implication: doses require re-titration after the autoinduction period<ref name="tegretol-label">FDA Prescribing Information, Tegretol (carbamazepine), Novartis, current revision. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/016608s120,018281s069lbl.pdf</ref>
| bioavailability    =
| bioavailability  = ~80% (oral)<ref name="tegretol-label" />
| pregnancy         =  
| pregnancy        = '''Substantial teratogenic risk''' including neural tube defects, craniofacial malformations, cardiac defects, and growth restriction; folic acid supplementation and effective contraception are required in reproductive-age patients<ref name="tegretol-label" />
| legal              =  
| legal             = [[USLegal:Prescription only|Rx-only]] in US
| intro              =  
| mechanism        = <vote slug="carbamazepine-mech-claim">Voltage-gated sodium channel blocker in the inactivated state (similar mechanism to lamotrigine), reducing high-frequency repetitive neuronal firing and presynaptic glutamate release. The trigeminal neuralgia efficacy reflects blockade of paroxysmal trigeminal afferent firing.</vote> '''Strong CYP3A4 inducer''' (and autoinducer) producing many interactions: reduces exposure of oral contraceptives, warfarin, lamotrigine, many neuroleptics and antidepressants, antiretrovirals, and direct oral anticoagulants. The '''HLA-B*15:02 allele substantially elevates Stevens-Johnson syndrome and toxic epidermal necrolysis risk''' in Asian populations; CPIC and FDA recommend pre-treatment HLA-B*15:02 testing in ancestry-at-risk patients. HLA-A*31:01 confers additional risk in European populations<ref name="cpic-hla">CPIC Guideline for HLA Genotype and Use of Carbamazepine and Oxcarbazepine, 2017. https://cpicpgx.org/guidelines/guideline-for-carbamazepine-and-hla-b/</ref>. Rare but recognized '''aplastic anemia and agranulocytosis''' warrant periodic CBC monitoring.
| pharmacokinetics  =  
| pharmacodynamics  =  
| indications        =  
| dosing             =  
| effects            =  
| contraindications  =  
| interactions       =  
| pregnancy_details  =
| monitoring         =
| counseling        =
| anecdotes          =
| seealso            =
| references        =
}}
}}


[[Category:Mood_Stabilizers]]
== References ==
<references />
 
[[Category:Anticonvulsants]]
[[Category:Mood stabilizers]]
[[Category:Sodium channel blockers]]

Latest revision as of 07:17, 23 May 2026

Carbamazepine
Tegretol (IR, XR, suspension), Carbatrol (ER), Equetro (ER for bipolar), Epitol

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Summary
Common uses
Partial-onset and generalized tonic-clonic seizures (FDA)0, Trigeminal neuralgia (FDA; the first-line and textbook indication)0, Bipolar I mania and mixed episodes (Equetro; FDA)0, Neuropathic pain (off-label)0
Pharmacy
Starting dose
Seizures: 200 mg PO BID, titrate by 200 mg/week to 800-1200 mg/day. Trigeminal neuralgia: 100-200 mg BID, titrate to 200-400 mg TID. Bipolar: 200 mg BID, titrate to 1600 mg/day
Preparations
IR tablets 200 mg; chewable 100 mg; oral suspension 100 mg/5 mL; XR tablets 100, 200, 400 mg (Tegretol XR); ER capsules 100, 200, 300 mg (Carbatrol, Equetro)
US FDA Max
1200 mg/day (adult seizures); 1600 mg/day (bipolar mania)
Pharmacology
Routes
Oral
Onset
Anticonvulsant effect within days; trigeminal neuralgia relief 24-72 hours; mood-stabilizing effect over weeks
Duration
BID-QID dosing (IR); BID for ER formulations
Half-life
Autoinduction: 25-65 hours initially, falling to 12-17 hours after 2-3 weeks of dosing as carbamazepine induces its own CYP3A4 metabolism. Major clinical implication: doses require re-titration after the autoinduction period[2]
Bioavailability
~80% (oral)[2]
Pregnancy
Substantial teratogenic risk including neural tube defects, craniofacial malformations, cardiac defects, and growth restriction; folic acid supplementation and effective contraception are required in reproductive-age patients[2]
Legal status
Rx-only in US
Purported mechanism
Voltage-gated sodium channel blocker in the inactivated state (similar mechanism to lamotrigine), reducing high-frequency repetitive neuronal firing and presynaptic glutamate release. The trigeminal neuralgia efficacy reflects blockade of paroxysmal trigeminal afferent firing.0 Strong CYP3A4 inducer (and autoinducer) producing many interactions: reduces exposure of oral contraceptives, warfarin, lamotrigine, many neuroleptics and antidepressants, antiretrovirals, and direct oral anticoagulants. The HLA-B*15:02 allele substantially elevates Stevens-Johnson syndrome and toxic epidermal necrolysis risk in Asian populations; CPIC and FDA recommend pre-treatment HLA-B*15:02 testing in ancestry-at-risk patients. HLA-A*31:01 confers additional risk in European populations[1]. Rare but recognized aplastic anemia and agranulocytosis warrant periodic CBC monitoring.

References

  1. CPIC Guideline for HLA Genotype and Use of Carbamazepine and Oxcarbazepine, 2017. https://cpicpgx.org/guidelines/guideline-for-carbamazepine-and-hla-b/
  2. 2.0 2.1 2.2 FDA Prescribing Information, Tegretol (carbamazepine), Novartis, current revision. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/016608s120,018281s069lbl.pdf