lamotrigine vs phenobarbital
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Side-by-side comparison of lamotrigine and phenobarbital. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
Phenobarbital/Primidone ↓ lamotrigine Decreased lamotrigine concentration approximately 40%. ( 7 , 12.3 ) Carbamazepine, phenytoin, phenobarbital, primidone, and rifampin decrease lamotrigine concentrations by approximately 40%.
Lamictal
Luminal
Lamotrigine is a medicine that can treat seizures and bipolar disorder. It works by reducing irregular electrical activity in the brain.
Phenobarbital is a medicine that can help control seizures and calm you down. It belongs to a class of drugs called barbiturates.
Lamotrigine can treat epilepsy in adults and children 2 years and older. It can help with partial-onset seizures, primary generalized tonic-clonic seizures, and generalized seizures of Lennox-Gastaut syndrome. It can also be used to delay mood episodes in adults with bipolar I disorder.
This medicine is used to treat generalized and partial seizures. Seizures are caused by unusual electrical activity in the brain. Phenobarbital helps to reduce this activity and prevent seizures.
Lamotrigine affects how nerves in the brain send signals to each other. It is thought to work by decreasing the release of certain chemicals. This helps to stabilize electrical activity and prevent seizures or mood swings.
Phenobarbital works by slowing down the activity of your brain and nervous system. It increases the effects of a natural chemical in the body called GABA. This helps to reduce seizures and promote relaxation.
- • Dizziness
- • Headache
- • Double vision
- • Uncoordinated movements
- • Nausea
- • Drowsiness
- • Sedation
- • Lethargy
- • Vertigo
- Rash 8,408
- Seizure 6,527
- Nausea 6,149
- Fatigue 5,915
- Dizziness 5,770
- Seizure 1,534
- Drug Interaction 635
- Toxicity To Various Agents 621
- Status Epilepticus 482
- Multiple-Drug Resistance 442
Lamotrigine can cause a serious skin rash that may require you to go to the hospital. This rash can be life-threatening. The risk is higher in children. Stop taking lamotrigine and see a doctor right away if you get a rash, fever, or swollen lymph nodes.
You should not take this medicine if you are allergic to barbiturates. Also, do not take it if you have a history of porphyria, severe liver problems, or breathing problems.
Tell your doctor if you are pregnant or plan to become pregnant. Lamotrigine may cause harm to an unborn baby. There is a pregnancy registry for women who take lamotrigine during pregnancy. You can enroll by calling 1-888-233-2334.
Tell your doctor if you are pregnant or plan to become pregnant. Phenobarbital can harm an unborn baby. Talk to your doctor about the risks and benefits of taking this medicine while breastfeeding.
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How to Read This lamotrigine vs phenobarbital Comparison
lamotrigine is classified in the Anticonvulsant drug class, while phenobarbital sits within the Anticonvulsant (Barbiturate) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, lamotrigine has 32,769 submissions while phenobarbital has 3,714. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to phenobarbital makes your body get rid of lamotrigine more quickly, which can lower the medicine's levels in your blood by about 40%.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for lamotrigine or phenobarbital.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.