Lamotrigine ER Dose Titration from 100mg to 150mg
To increase lamotrigine ER from 100mg to 150mg daily, add a 50mg tablet to the current dose while maintaining once-daily dosing, with no need for gradual titration between these specific doses.
Rationale for Direct Dose Increase
Lamotrigine ER (extended-release) can be safely increased from 100mg to 150mg without intermediate titration steps because:
- This is a modest 50% increase in an already established dose
- The patient is already taking lamotrigine and has demonstrated tolerability
- The extended-release formulation helps minimize peak-related side effects
Benefits of Extended-Release Formulation
The extended-release formulation of lamotrigine offers several advantages when increasing doses:
- Provides more stable serum concentrations throughout the day
- Reduces peak-related adverse effects like dizziness and visual disturbances
- Maintains higher trough levels which may improve seizure control 1
- Allows for convenient once-daily dosing
Important Monitoring Considerations
After increasing the dose:
- Monitor for any new adverse effects, particularly skin rash (though risk is minimal with established therapy)
- Assess therapeutic response after 2 weeks at the new dose
- Consider checking lamotrigine serum levels if there are concerns about efficacy or toxicity
Special Considerations
- If the patient is taking enzyme-inducing medications (like carbamazepine or phenytoin), they may require higher lamotrigine doses
- If taking valproate concurrently, dose increases should be more conservative as valproate increases lamotrigine levels 2
- Maintain once-daily dosing with the ER formulation to preserve its pharmacokinetic advantages
Common Pitfalls to Avoid
- Switching between immediate-release and extended-release formulations without dose adjustment
- Failing to recognize drug interactions that affect lamotrigine metabolism
- Discontinuing lamotrigine abruptly, which can precipitate seizures
This straightforward approach to increasing lamotrigine ER from 100mg to 150mg daily maintains the benefits of the extended-release formulation while providing a higher therapeutic dose.