it is a summery for Lamotrigine toxicity .it's reference is goldfrank's toxicologic emergencies 10th edition

1. Lamotrigine toxicity
Dr.Aliyeh Bazi
Resident of clinical pharmacy

2. background
Lamotrigine use
• Approved as an adjunct
medication for treatment of
partial seizures or secondary
generalized seizures
• Bipolar mood disorders
 Available Forms
• Tablets: 25 mg, 50 mg, 100 mg
• Oral solution 10 mg/ml
• It is a category C medication with
limited human data in pregnancy.
Pharmacokinetics
• 98% bioavailability
• Distribution: 1.2-1.5 L/kg; 55%-56%
protein bound
• Metabolism: glucuronidated to
inactive metabolite; phenytoin and
CBZ induce metabolism lamotrigine
; VPA competes with metabolism of
lamotrigine
• Half-life: 25 hours
• Therapeutic blood levels: 1-4
mcg/mL
• Laboratory Assessment:
Lamotrigine concentrations greater
than 14 mg/L are potentially toxic.

3. Clinical Manifestations
• Neurologic manifestations : lethargy, ataxia, nystagmus
• GI symptoms
• symptoms related to sodium channel blockade:
Coma, hypokinesis, seizures, status epilepticus, hypertension,
tachycardia, and cardiac conduction disturbances maythird-
degree heart block
• adverse effect in chronic therapy: rashes,
rhabdomyolysis, elevated hepatic aminotransferases, and
serum creatinine phosphokinase concentrations, findings
suggestive of a hypersensitivity reaction

4. Management
• Activated charcoal
• Supportive care and ECG monitoring
• Benzodiazepines
• Data on HD and hemoperfusion are not available;
but : based on its size, relatively low protein binding, and
volume of distribution (1.4 L/kg), lamotrigine should be
removed by HD.
• IV fat emulsion was used successfully in two severe cases of
lamotrigine poisoning presenting with coma, seizures, and
QRS complex widening