Lamotrigine - Revision history

MDElliottMD: home-claude: fix CPIC citation hard errors (CPIC scope does not cover these medicines; correct to PharmGKB/DPWG/FDA label where applicable)

2026-05-27T02:23:04Z

home-claude: fix CPIC citation hard errors (CPIC scope does not cover these medicines; correct to PharmGKB/DPWG/FDA label where applicable)

← Older revision		Revision as of 02:23, 27 May 2026
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	\| pregnancy = '''Among the safest mood stabilizers in pregnancy''' with reassuring monotherapy registry data, in sharp contrast to valproate. Estrogen-containing contraceptives accelerate lamotrigine metabolism, requiring dose adjustments at start and stop of contraception<ref name="lamictal-label" />		\| pregnancy = '''Among the safest mood stabilizers in pregnancy''' with reassuring monotherapy registry data, in sharp contrast to valproate. Estrogen-containing contraceptives accelerate lamotrigine metabolism, requiring dose adjustments at start and stop of contraception<ref name="lamictal-label" />
	\| legal = [[USLegal:Prescription only\|Rx-only]] in US. Carries the FDA '''Boxed Warning for serious skin reactions''' including Stevens-Johnson syndrome and toxic epidermal necrolysis, with the risk concentrated in the first 2-8 weeks of therapy and elevated by rapid titration<ref name="lamictal-label" />		\| legal = [[USLegal:Prescription only\|Rx-only]] in US. Carries the FDA '''Boxed Warning for serious skin reactions''' including Stevens-Johnson syndrome and toxic epidermal necrolysis, with the risk concentrated in the first 2-8 weeks of therapy and elevated by rapid titration<ref name="lamictal-label" />
	\| mechanism = <vote slug="lamotrigine-mech-claim">Voltage-gated sodium channel blocker in the inactivated state, reducing high-frequency repetitive neuronal firing and consequently reducing presynaptic glutamate release. The mood-stabilizing mechanism is incompletely characterized but is plausibly the same glutamatergic dampening applied to limbic circuits.</vote> Metabolized predominantly by UGT1A4 glucuronidation (not CYP), which is why '''valproate doubles exposure''' (UGT inhibition) and '''carbamazepine, phenytoin, rifampin halve exposure''' (UGT induction). ~~The~~ HLA-B15:02 ~~allele substantially elevates~~ SJS ~~risk~~ in Asian populations; ~~CPIC and FDA support pre~~-~~treatment~~ HLA-B15:~~02 testing in at~~-~~risk patients~~<ref name="~~cpic-hla~~">~~CPIC Guideline for~~ HLA ~~Genotype~~ and ~~Use of Carbamazepine and Oxcarbazepine, applicable by extension to~~ lamotrigine. ~~https~~:~~//cpicpgx~~.~~org~~/~~guidelines~~/~~guideline~~-for-carbamazepine-~~and-hla-b/<~~/~~ref~~>.		\| mechanism = <vote slug="lamotrigine-mech-claim">Voltage-gated sodium channel blocker in the inactivated state, reducing high-frequency repetitive neuronal firing and consequently reducing presynaptic glutamate release. The mood-stabilizing mechanism is incompletely characterized but is plausibly the same glutamatergic dampening applied to limbic circuits.</vote> Metabolized predominantly by UGT1A4 glucuronidation (not CYP), which is why '''valproate doubles exposure''' (UGT inhibition) and '''carbamazepine, phenytoin, rifampin halve exposure''' (UGT induction). HLA-B15:02 is associated with lamotrigine-induced SJS/TEN in Asian populations, but the association is weaker than for carbamazepine.<ref name="zeng2015lam">Zeng T, Long YS, Min FL, Liao WP. Association of HLA-B1502 allele with lamotrigine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Han Chinese subjects: a meta-analysis. Int J Dermatol. 2015;54(4):488-493. PMID 25428396.</ref> In European-ancestry patients, HLA-B38:01 has been identified as a risk allele for lamotrigine-induced SJS.<ref name="kazeem2009lam">Kazeem GR, Cox C, Aponte J, Messenheimer J. High-resolution HLA genotyping and severe cutaneous adverse reactions in lamotrigine-treated patients. Pharmacogenet Genomics. 2009;19(9):661-665. PMID 19668019.</ref> The FDA Lamictal label notes HLA-B15:02 as a risk factor for lamotrigine SJS/TEN in patients of Asian ancestry but does not require pre-treatment HLA testing for lamotrigine as the carbamazepine label does.<ref name="lamictal-label" /> CPIC has published a guideline for carbamazepine and oxcarbazepine HLA testing; no formal CPIC guideline for lamotrigine HLA testing has been published.
	}}		}}

MDElliottMD: parser-claude: Lamotrigine MedTemplate refill, Top 300 stub upgrade

2026-05-23T06:41:45Z

parser-claude: Lamotrigine MedTemplate refill, Top 300 stub upgrade

← Older revision		Revision as of 06:41, 23 May 2026
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	{{MedTemplate		{{MedTemplate
	\| generic = Lamotrigine		\| generic = Lamotrigine
	\| brand = Lamictal		\| brand = Lamictal (IR), Lamictal XR, Lamictal ODT
	\| 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~~; inhibits glutamate release~~		\| uses = <vote slug="partial-seizures-use">Partial-onset and generalized tonic-clonic seizures (FDA, adjunct or monotherapy)</vote>, <vote slug="lennox-gastaut-use">Lennox-Gastaut syndrome (FDA)</vote>, <vote slug="bipolar-maintenance-use">Bipolar I disorder maintenance, particularly prevention of depressive episodes (FDA)</vote>, <vote slug="bipolar-depression-acute-use">Bipolar depression, acute (off-label, modest evidence)</vote>
	\| uses =		\| starting_dose = '''Slow titration is essential to mitigate Stevens-Johnson syndrome risk.''' Standard adult: 25 mg PO daily for 2 weeks, then 50 mg daily for 2 weeks, then 100 mg daily for 1 week, then 200 mg daily target. Double the rate if on enzyme inducers (carbamazepine, phenytoin); halve the rate if on valproate
	\| starting_dose =		\| preparations = IR tablets 25, 100, 150, 200 mg; chewable dispersible tablets 2, 5, 25 mg; ODT 25, 50, 100, 200 mg; XR tablets 25, 50, 100, 200, 250, 300 mg
	\| preparations =		\| fda_max = 400 mg/day (bipolar monotherapy); 700 mg/day (epilepsy with enzyme-inducing comedication)
	\| fda_max =		\| pill_id =
	\| routes =		\| routes = Oral
	\| onset =		\| onset = Antiepileptic effect within days at therapeutic level; mood-stabilizing effect emerges over weeks
	\| duration =		\| duration = 24 hours (often divided BID at higher doses)
	\| halflife =		\| halflife = ~25-33 hours alone; ~15 hours with enzyme inducers; '''≥60 hours with valproate''' (UGT inhibition)<ref name="lamictal-label">FDA Prescribing Information, Lamictal (lamotrigine), GSK, current revision. https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/020241s045s051lbl.pdf</ref>
	~~\| bioavailability =~~		\| bioavailability = ~98% (oral)<ref name="lamictal-label" />
	~~\| pregnancy~~ =		\| pregnancy = '''Among the safest mood stabilizers in pregnancy''' with reassuring monotherapy registry data, in sharp contrast to valproate. Estrogen-containing contraceptives accelerate lamotrigine metabolism, requiring dose adjustments at start and stop of contraception<ref name="lamictal-label" />
	~~\| legal~~ =		\| legal = [[USLegal:Prescription only\|Rx-only]] in US. Carries the FDA '''Boxed Warning for serious skin reactions''' including Stevens-Johnson syndrome and toxic epidermal necrolysis, with the risk concentrated in the first 2-8 weeks of therapy and elevated by rapid titration<ref name="lamictal-label" />
	\| ~~intro~~ =		\| mechanism = <vote slug="lamotrigine-mech-claim">Voltage-gated sodium channel blocker in the inactivated state, reducing high-frequency repetitive neuronal firing and consequently reducing presynaptic glutamate release. The mood-stabilizing mechanism is incompletely characterized but is plausibly the same glutamatergic dampening applied to limbic circuits.</vote> Metabolized predominantly by UGT1A4 glucuronidation (not CYP), which is why '''valproate doubles exposure''' (UGT inhibition) and '''carbamazepine, phenytoin, rifampin halve exposure''' (UGT induction). The HLA-B15:02 allele substantially elevates SJS risk in Asian populations; CPIC and FDA support pre-treatment HLA-B15:02 testing in at-risk patients<ref name="cpic-hla">CPIC Guideline for HLA Genotype and Use of Carbamazepine and Oxcarbazepine, applicable by extension to lamotrigine. https://cpicpgx.org/guidelines/guideline-for-carbamazepine-and-hla-b/</ref>.
	~~\| pharmacokinetics~~ =
	\| ~~pharmacodynamics~~ =
	~~\| indications~~ =
	\| ~~dosing~~ =
	\| ~~effects~~ =
	~~\| interactions = <pharmaInteractions~~/>
	\| ~~pregnancy_details =~~
	~~\| monitoring~~ =
	~~\| counseling~~ =
	~~\| anecdotes =~~
	~~\| seealso =~~
	~~\| references~~ =
	}}		}}

			== References ==
			<references />

			[[Category:Anticonvulsants]]
	[[Category:Mood stabilizers]]		[[Category:Mood stabilizers]]
	[[Category:Sodium channel blockers]]		[[Category:Sodium channel blockers]]
	~~[[Category:Antiepileptics]]~~
	~~[[Category:Mood stabilizers]]~~

CategoryClaude: Sentence-case category link fixup (drop residual Mood_Stabilizers)

2026-05-23T05:05:03Z

Sentence-case category link fixup (drop residual Mood_Stabilizers)

← Older revision		Revision as of 05:05, 23 May 2026
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	}}		}}

	[[Category:~~Mood_Stabilizers~~]]		[[Category:Mood stabilizers]]
	[[Category:Sodium channel blockers]]		[[Category:Sodium channel blockers]]
	[[Category:Antiepileptics]]		[[Category:Antiepileptics]]
	[[Category:Mood stabilizers]]		[[Category:Mood stabilizers]]

CategoryClaude: Sentence-case category link per house style (Mood_Stabilizers → Mood_stabilizers)

2026-05-23T05:02:20Z

Sentence-case category link per house style (Mood_Stabilizers → Mood_stabilizers)

← Older revision		Revision as of 05:02, 23 May 2026
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	[[Category:Sodium channel blockers]]		[[Category:Sodium channel blockers]]
	[[Category:Antiepileptics]]		[[Category:Antiepileptics]]
	[[Category:Mood ~~Stabilizers~~]]		[[Category:Mood stabilizers]]

MDElliottMD: Category taxonomy ship: retag Anticonvulsants -> Antiepileptics

2026-05-22T00:36:47Z

Category taxonomy ship: retag Anticonvulsants -> Antiepileptics

← Older revision		Revision as of 00:36, 22 May 2026
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	[[Category:Mood_Stabilizers]]		[[Category:Mood_Stabilizers]]
	[[Category:Sodium channel blockers]]		[[Category:Sodium channel blockers]]
	[[Category:~~Anticonvulsants~~]]		[[Category:Antiepileptics]]
	[[Category:Mood Stabilizers]]		[[Category:Mood Stabilizers]]

MDElliottMD: Dedupe migration per interface-claude 2026-05-20: Anticonvulsants / Antiepileptics merged into canonical Anticonvulsants. Member retagged.

2026-05-19T18:00:14Z

Dedupe migration per interface-claude 2026-05-20: Anticonvulsants / Antiepileptics merged into canonical Anticonvulsants. Member retagged.

← Older revision		Revision as of 18:00, 19 May 2026
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	[[Category:Mood_Stabilizers]]		[[Category:Mood_Stabilizers]]
	[[Category:Sodium channel blockers]]		[[Category:Sodium channel blockers]]
	[[Category:Anticonvulsants ~~/ Antiepileptics~~]]		[[Category:Anticonvulsants]]
	[[Category:Mood Stabilizers]]		[[Category:Mood Stabilizers]]

MDElliottMD: Comprehensive categorization: +Sodium channel blockers, Anticonvulsants / Antiepileptics, Mood Stabilizers

2026-05-15T18:42:09Z

Comprehensive categorization: +Sodium channel blockers, Anticonvulsants / Antiepileptics, Mood Stabilizers

← Older revision		Revision as of 18:42, 15 May 2026
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	[[Category:Mood_Stabilizers]]		[[Category:Mood_Stabilizers]]
			[[Category:Sodium channel blockers]]
			[[Category:Anticonvulsants / Antiepileptics]]
			[[Category:Mood Stabilizers]]

MDElliottMD: Pharmacopedia: add

2026-05-14T03:30:56Z

Pharmacopedia: add <pharmaInteractions/>

← Older revision		Revision as of 03:30, 14 May 2026
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	\| dosing =		\| dosing =
	\| effects =		\| effects =
	\| interactions =		\| interactions = <pharmaInteractions/>
	\| pregnancy_details =		\| pregnancy_details =
	\| monitoring =		\| monitoring =

MDElliottMD: Pharmacopedia: remove contraindications parameter

2026-05-14T02:40:38Z

Pharmacopedia: remove contraindications parameter

← Older revision		Revision as of 02:40, 14 May 2026
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	\| dosing =		\| dosing =
	\| effects =		\| effects =
	~~\| contraindications =~~
	\| interactions =		\| interactions =
	\| pregnancy_details =		\| pregnancy_details =

MDElliottMD: Added empty fda_max parameter to MedTemplate call

2026-05-13T02:32:40Z

Added empty fda_max parameter to MedTemplate call

← Older revision		Revision as of 02:32, 13 May 2026
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	\| starting_dose =		\| starting_dose =
	\| preparations =		\| preparations =
			\| fda_max =
	\| routes =		\| routes =
	\| onset =		\| onset =
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	[[Category:Mood_Stabilizers]]		[[Category:Mood_Stabilizers]]