Lamotrigine

Clinical Biochemistry

Background Information

• Lamotrigine is an effective anticonvulsant but is also useful in the treatment of depression in bipolar disorders.
• There is no indication for routine monitoring of lamotrigine levels unless there is evidence of ineffectiveness, poor adherence or toxicity (NICE NG217).
• Monitoring during pregnancy is advised (NICE CG192; MHRA).

Patient Preparation

No specific preparation required.

Sample Requirements

Pre-dose samples required.

For adults, one 4 mL EDTA tube

For children, blood taken into one paediatric EDTA tube

Storage/Transport

Send at ambient temperature to the laboratory on the day the sample is collected. Samples may be stored refrigerated overnight if unavoidable.

Required Information

Relevant clinical details including the reason for the request, date and time of the last dose, and date and time of sample.

Turnaround Times

Samples are sent to a referral laboratory for analysis with results expected back within 2 weeks.

Therapeutic Ranges

Ranges and interpretation reported as provided by referral laboratory.

Further Information

For more information about therapeutic drug monitoring visit Lab Tests Online.

Guidelines referred to on this page:

• NICE NG217 Epilepsies in children, young people and adults
• NICE CG192 Antenatal and Post-Natal Mental Health
• MHRA Updated safety advice on antiepileptic drugs in pregnancy

Page last updated: 29/09/2025 | Page last reviewed: 29/09/2025