Action and Spectrum

Actions and Spectrum 

lamotrigine’s exact mode of action is unknown, although it is believed to involve blocking the release of certain neurotransmitters like glutamate and aspartate, which can result in seizures and mood swings. 

lamotrigine’s therapeutic range includes treating epileptic patients’ focal (partial) and generalised seizures. Additionally, it is used to stop both manic and depressed mood swings in persons with bipolar illness. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Depression 

Flu syndrome 

Infection 

Emotional lability 

Nausea 

Cough 

Incoordination 

Pruritus 

Constipation 

Diarrhea 

Dyspepsia 

Palpitations 

Vomiting 

Vaginitis 

Nystagmus 

Decreased memory 

Arthralgia 

Neck pain 

Anxiety 

Chills 

Rash 

Amenorrhea 

Hot flashes 

Abdominal pain 

Malaise 

Seizure exacerbation 

Vertigo 

1-10% 

Dermatitis (2-5%) 

Peripheral edema (2-5%) 

Abnormal thoughts (1-5%) 

Tremor (4%) 

Increased libido (2-5%) 

Rectal hemorrhage (2-5%) 

Suicidal ideation (2-5%) 

Urinary frequency (1-5%) 

Edema (1-5%) 

Fever (1-5%) 

Migraine (1-5%) 

Fatigue (8%) 

Insomnia (6-10%) 

Chest pain (5%) 

Dry skin (2-5%) 

Weakness (2-5%) 

Agitation (1-5%) 

Dysarthria (1-5%) 

>10% 

Somnolence (14%) 

Ataxia (22%) 

Blurred vision (16-20%) 

Dizziness (38%) 

Diplopia (26-30%) 

Headache (29%) 

Rhinitis (11-15%) 

Post marketing reports 

Esophagitis 

Aseptic meningitis 

Pancreatitis 

Aggression 

Progressive immunosuppression 

Cardiac rhythm and conduction abnormalities 

Vasculitis 

Apnea 

Exacerbation of Parkinsonian symptoms in patients with pre-existing Parkinson’s disease 

Rhabdomyolysis 

Lupus-like reaction 

Agranulocytosis, hemolytic anemia 

Black Box Warning

Black Box Warning 

For the possibility of severe skin reactions such Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), lamotrigine carries a black box warning.  

lamotrigine should be stopped as soon as a rash appears, unless it is obvious that the rash is unrelated to the medicine, according to the caution. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• lamotrigine or any of its ingredients are known to cause hypersensitivity. 
• lamotrigine should not be used again by patients who have had a potentially fatal skin response to it. 
• If a patient has hepatic impairment or is taking drugs that reduce the seizure threshold, they should not start taking lamotrigine if they are also taking valproic acid or divalproex sodium since this might raise the chance of significant skin reactions. 

Caution: 

• lamotrigine patients should proceed with caution when driving or using heavy machinery until they are familiar with how the medicine affects them. It can produce dizziness, sleepiness, and blurred vision. 

• It is important to regularly monitor patients who have a history of depression or suicidal thoughts or actions for the appearance or exacerbation of these symptoms while using 

• lamotrigine should be taken with caution in patients who have a history of seizure disorder since it may increase the frequency or severity of seizures in certain people. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excretion into human milk is known 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were lack of studies on pregnant women and no evidence of risk to the foetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology 

lamotrigine is an anticonvulsant or antiepileptic medicine that is structurally distinct from other antiepileptic medications. Although the precise mode of action of lamotrigine is not entirely known, it is believed to function by preventing the brain’s excitatory neurotransmitter glutamate from being released. lamotrigine assists in lowering the probability of seizures and mood swings in this way. 

Pharmacodynamics 

It is thought that lamotrigine works by altering voltage-gated sodium channels, which are essential for the development and transmission of action potentials in neurons. lamotrigine specifically suppresses persistent, recurrent neuronal activation, which can aid in halting the progression of seizure activity in the brain. 

Pharmacokinetics 

Absorption   

Following oral treatment, lamotrigine is well absorbed, reaching peak plasma concentrations in 1.4 to 4.8 hours. lamotrigine’s absorption may be slowed down by food, although this does not seem to have an impact on how much is absorbed overall. lamotrigine is also offered in orally disintegrating pills, which are more quickly absorbed than normal tablets and disintegrate swiftly in the mouth. 

Distribution 

The volume of distribution of around 1.4 L/kg, lamotrigine is widely dispersed throughout the body. Most of the medicine between 55% and 68% is bonded to plasma proteins, especially albumin. The drug is largely protein-bound. 

Metabolism 

lamotrigine undergoes most of its metabolism in the liver, mostly through glucuronidation, which entails the addition of a glucuronic acid molecule to the medication to make it more soluble in water and simpler to excrete from the body. The metabolism of lamotrigine may potentially involve additional metabolic processes including oxidation and N-glucuronidation in a modest capacity. 

Elimination and excretion 

Approximately 94% of the dosage of lamotrigine and its metabolites are excreted in the urine within 7 days of treatment. The medication is partially excreted in the feces. The lamotrigine’s half-life of elimination in healthy persons is around 25 to 35 hours, however it may be longer in patients with hepatic impairment. 

Adminstartion

Administration:  

lamotrigine comes in a variety of forms, including chewable, immediate-release, and extended-release pills as well as tablets that dissolve in the mouth.  

lamotrigine can be taken with or without meals, however it may take longer for the medicine to reach its peak plasma concentration if taken with food. lamotrigine’s extended-release medication needs to be taken whole; it shouldn’t be crushed or chewed. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: lamotrigine 

Why do we use lamotrigine? 

Generalised seizures, partial seizures, and Lennox-Gastaut syndrome can all be treated with lamotrigine, an antiepileptic drug. It can be used either by alone or in conjunction with other antiepileptic medications. 

lamotrigine is used for the maintenance treatment of bipolar disorder to postpone the onset of mood episodes (depression, mania, hypomania, and mixed episodes) in patients receiving treatment for acute mood episodes with conventional medication.