Lamictal® (lamotrigine) is a drug used to control epileptic seizures. Physicians may also order it to treat migraines, treatment-resistant depression or trigeminal neuralgia. Several conditions can affect the blood levels and efficacy of physician-prescribed Lamictal®: intestinal absorption variations, liver disease, protein binding rates, combinations with other drugs, etc. The Lamictal® test measures blood levels of the drug at least 10 hours after the last dose (unless otherwise indicated by the physician) and results are expressed in micromoles of Lamictal per litre of blood (µmol/L).
For epileptic seizure control, most individuals will respond adequately and with minimal side effects at a level between 4.0 and 39 µmol/L of Lamictal® (measured at least 10 hours after the last dose). In some individuals, or for other uses, this therapeutic zone may not achieve the desired effect, while others will experience excessive side effects even if the level remains within the therapeutic zone. Side effects vary widely and include dizziness, weakness, blurred or double vision, nausea and vomiting.