What is the best time to take extended release Lamictal (lamotrigine)?

Best Time to Take Extended Release Lamotrigine

Extended release lamotrigine (Lamictal XR) should be taken once daily, preferably in the evening, to maintain stable blood levels and optimize seizure control while minimizing peak-related adverse effects.

Pharmacokinetic Considerations

Extended release lamotrigine offers several advantages over immediate release formulations:

• Provides more stable serum concentrations with less fluctuation between peak and trough levels 1
• Reduces peak-related toxicity symptoms such as dizziness, blurred vision, and unsteadiness 1
• Maintains higher trough levels which may improve seizure control 1
• Has a half-life of approximately 22.8 to 37.4 hours in patients on monotherapy 2

Evidence Supporting Evening Administration

While specific guidelines don't explicitly state the optimal time of day for taking extended release lamotrigine, several factors support evening administration:

1. Improved Seizure Control: A study showed that conversion from immediate-release to extended-release lamotrigine resulted in a 46% median reduction in seizure frequency, with 47% of patients experiencing >50% reduction in seizures 1. Taking the medication in the evening ensures higher blood levels during sleep and early morning hours when seizures commonly occur.

2. Adverse Effect Management: Common side effects of lamotrigine include:

   • Dizziness and headache 3
   • Insomnia 4
   • Visual disturbances 1

   Evening dosing allows peak adverse effects to occur during sleep, minimizing their impact on daily functioning.

3. Medication Adherence: Once-daily dosing in the evening can improve medication adherence compared to multiple daily doses required with immediate-release formulations.

Special Considerations

• Food Effects: Food reduces the bioavailability of lamotrigine 5. For optimal absorption, extended-release lamotrigine should ideally be taken consistently either with or without food. If taking with food, maintain consistency in timing relative to meals.

• Drug Interactions: The dosage of lamotrigine requires adjustment when used with certain medications:

  • Enzyme inducers (carbamazepine, phenytoin, phenobarbital) reduce lamotrigine's half-life 2
  • Valproic acid increases lamotrigine's half-life 2

• Consistent Timing: Whatever time is chosen, it's important to take extended-release lamotrigine at approximately the same time each day to maintain stable blood levels.

Practical Recommendations

• Take extended-release lamotrigine once daily in the evening (e.g., before bedtime)
• Maintain consistent timing relative to food intake
• If experiencing significant morning drowsiness, consider adjusting to earlier evening administration
• Do not crush, chew, or split extended-release tablets as this would defeat the purpose of the extended-release formulation

By taking extended-release lamotrigine in the evening, patients can benefit from improved seizure control while minimizing the impact of potential adverse effects on daily activities.