Carbamazepine: Difference between revisions
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MDElliottMD (talk | contribs) Comprehensive categorization: +Sodium channel blockers, Anticonvulsants / Antiepileptics, Mood Stabilizers |
MDElliottMD (talk | contribs) parser-claude: Carbamazepine MedTemplate refill, Top 300 stub upgrade |
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{{MedTemplate | {{MedTemplate | ||
| generic | | generic = Carbamazepine | ||
| brand | | brand = Tegretol (IR, XR, suspension), Carbatrol (ER), Equetro (ER for bipolar), Epitol | ||
| structure | | structure = | ||
| classes | | classes = [[:Category:Anticonvulsants|Anticonvulsant]], [[:Category:Mood stabilizers|Mood stabilizer]], [[:Category:Sodium channel blockers|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 | ||
| | | 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. | ||
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[[Category: | == References == | ||
<references /> | |||
[[Category:Anticonvulsants]] | |||
[[Category:Mood stabilizers]] | |||
[[Category:Sodium channel blockers]] | [[Category:Sodium channel blockers]] | ||