Comprehensive medication guide to Lamictal XR including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$30 copay for generic lamotrigine ER on most insurance plans at Tier 1–2; brand Lamictal XR is Tier 3–4 and typically requires prior authorization with a higher copay.
Estimated Cash Pricing
$318 average retail for generic lamotrigine ER; as low as $16.20 with a GoodRx coupon or $28 with SingleCare for a 30-day supply of generic. Brand-name Lamictal XR retails for approximately $1,225/month.
Medfinder Findability Score
62/100
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Lamictal XR is the brand name for lamotrigine extended-release tablets, manufactured by GlaxoSmithKline (GSK). It is a once-daily anticonvulsant (anti-seizure medication) and mood stabilizer approved by the FDA for patients aged 13 years and older. The extended-release formulation allows once-daily dosing, compared to the twice-daily dosing required with immediate-release lamotrigine (Lamictal).
Lamictal XR is FDA-approved for adjunctive therapy for partial-onset seizures, primary generalized tonic-clonic (PGTC) seizures, and generalized seizures of Lennox-Gastaut syndrome, as well as conversion to monotherapy for partial-onset seizures. It is also approved for maintenance treatment of bipolar I disorder in adults.
Lamictal XR is available as extended-release tablets in 25 mg, 50 mg, 100 mg, 200 mg, and 300 mg strengths. Tablets must be swallowed whole and must never be chewed, crushed, or divided. Generic lamotrigine extended-release (lamotrigine ER) is FDA-rated as therapeutically equivalent (AB-rated) to Lamictal XR.
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Lamictal XR works primarily by blocking voltage-sensitive sodium channels in neuronal cell membranes. Specifically, it binds to sodium channels in their inactivated state — the state they enter immediately after firing — and stabilizes that state, making it harder for the channel to quickly reset and fire again. This selectively suppresses the rapid, repetitive neuronal firing that occurs during seizures, while leaving normal neuronal activity relatively unaffected.
Lamotrigine also inhibits the presynaptic release of glutamate — the brain's primary excitatory neurotransmitter. By reducing glutamate release, it further dampens abnormal neuronal excitability and helps prevent seizures from spreading through the brain.
For bipolar I disorder, these same mechanisms stabilize the abnormal neuronal excitability in the brain's limbic (emotion-processing) regions that underlies extreme mood episodes. Lamotrigine is particularly effective at preventing the depressive pole of bipolar I disorder — more so than most other mood stabilizers.
25 mg — extended-release tablet
Starting/titration dose
50 mg — extended-release tablet
Titration dose
100 mg — extended-release tablet
Common maintenance dose component
200 mg — extended-release tablet
Standard maintenance dose for many patients
300 mg — extended-release tablet
Higher maintenance dose for patients on enzyme-inducing AEDs
As of 2026, Lamictal XR (lamotrigine extended-release) is not listed on the FDA's national drug shortage database. However, the XR formulation is genuinely harder to find at retail pharmacies than immediate-release lamotrigine. The extended-release version has lower overall prescription volume, which means pharmacies stock smaller quantities — making stock-outs more common when local demand increases or a supplier experiences a delay.
The Lamictal XR findability score is 62/100, reflecting intermittent availability challenges rather than a declared shortage. The problem is fragmented: a pharmacy two miles away may have your exact dosage strength when your usual pharmacy is out. Patients are frequently able to find their medication by calling independent pharmacies, trying a hospital outpatient pharmacy, or using mail-order pharmacy for 90-day supplies.
medfinder can call pharmacies near you to find which ones have Lamictal XR in stock and text you the results — visit medfinder.com to get started.
Lamictal XR is not a controlled substance and has no DEA scheduling restrictions, so any licensed prescriber with prescribing authority can write a prescription for it. In practice, prescribers vary by indication:
Telehealth prescribing is available for Lamictal XR for bipolar I disorder management. Because it is not a controlled substance, telehealth providers can prescribe and manage it without in-person visit requirements in most states. For epilepsy, telehealth neurology is available but may require in-person follow-up for EEG monitoring.
No — Lamictal XR (lamotrigine extended-release) is not a controlled substance and has no DEA schedule. Lamotrigine has no known abuse potential and does not produce physical dependence or euphoric effects. Any licensed prescriber with prescribing authority can write a prescription for Lamictal XR without the special licenses or restrictions that apply to Schedule II, III, or IV controlled substances.
While Lamictal XR is not a controlled substance, abrupt discontinuation is still dangerous — particularly for epilepsy patients, where stopping lamotrigine suddenly can trigger life-threatening seizures (status epilepticus). This risk is pharmacological (related to seizure threshold), not related to dependence or withdrawal in the traditional sense. Always taper lamotrigine under medical supervision rather than stopping suddenly.
Lamictal XR carries an FDA boxed warning for life-threatening skin reactions. Report any new rash to your prescriber immediately. Common side effects include:
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Lamictal (lamotrigine immediate-release)
Same active ingredient; taken twice daily instead of once daily; far more widely stocked; appropriate bridge when XR is unavailable
Levetiracetam (Keppra)
Broad-spectrum anticonvulsant with minimal drug interactions; affordable generic; may cause psychiatric side effects including irritability
Valproate / Divalproex (Depakote)
Broad-spectrum AED and mood stabilizer for acute mania; significant teratogenicity risk in women of childbearing potential; doubles lamotrigine levels if used together
Lithium (Lithobid)
Gold-standard mood stabilizer for bipolar I disorder; requires blood level monitoring; effective for both mania and depression prevention
Oxcarbazepine (Trileptal)
Sodium channel blocker for focal seizures; better tolerated than carbamazepine with fewer drug interactions
Prefer Lamictal XR? We can find it.
Valproate (Depakote)
majorInhibits lamotrigine glucuronidation — doubles lamotrigine blood levels. Require ~50% lower starting and maintenance doses of lamotrigine. Combination also increases serious rash risk.
Carbamazepine (Tegretol)
majorInduces lamotrigine glucuronidation — reduces lamotrigine levels by ~40%. Requires approximately double the usual lamotrigine maintenance dose.
Phenytoin (Dilantin)
majorEnzyme inducer — reduces lamotrigine levels by ~40%. Higher lamotrigine doses required.
Phenobarbital / Primidone
majorEnzyme inducers — reduce lamotrigine levels by ~40%. Higher lamotrigine doses required.
Estrogen-containing oral contraceptives
majorReduces lamotrigine levels by ~50%. Dose adjustments needed when starting or stopping. Lamotrigine levels spike during pill-free week, potentially causing toxicity symptoms.
Rifampin
majorPotent enzyme inducer — significantly reduces lamotrigine levels. Higher doses required.
Lopinavir/ritonavir, Atazanavir/ritonavir
moderateHIV protease inhibitors that induce glucuronidation and reduce lamotrigine levels.
Topiramate (Topamax)
moderateLamotrigine may increase topiramate blood levels — monitor for topiramate toxicity.
St. John's Wort
moderateHerbal enzyme inducer — reduces lamotrigine levels; avoid concurrent use.
Lamictal XR (lamotrigine extended-release) is a cornerstone medication for epilepsy and bipolar I disorder that offers the clinical benefit of once-daily dosing. It is not in a declared national shortage as of 2026, but the XR formulation is less widely stocked than immediate-release lamotrigine — and the consequences of running out are more severe than with most other medications.
Patients can significantly reduce both cost and availability stress by switching to generic lamotrigine ER (as low as $16/month with a GoodRx coupon), using mail-order pharmacy for 90-day supplies, and starting their refill search 7–10 days before running out.
If you're having trouble finding Lamictal XR in stock, medfinder can call pharmacies in your area to find out which ones can fill your prescription. Visit medfinder.com to get started.
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Real-time availability
Medfinder is actively checking pharmacy inventory for Lamictal XR. We don't publish a number until we have enough verified pharmacy checks to be accurate — start a search and our team confirms current availability near you, usually within 24 hours.
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