IV to PO Conversion for Lacosamide
Lacosamide can be converted from intravenous to oral administration at the same total daily dose with a 1:1 ratio, as both formulations have equivalent bioavailability. 1, 2
Conversion Dosing
- Use the same total daily dose when switching from IV to oral lacosamide - no dose adjustment is required 1, 3
- The oral tablet formulation has bioavailability similar to IV infusion at the same dosage 4
- Patients can be switched directly without a transition period or dose modification 5, 3
Clinical Evidence Supporting 1:1 Conversion
- A double-blind randomized trial (n=59) demonstrated that IV lacosamide administered as 30- or 60-minute infusions twice daily showed a safety and tolerability profile consistent with oral lacosamide when used as replacement therapy 3
- The tolerability profile of IV lacosamide was equivalent to oral lacosamide, with all adverse effects considered mild or moderate 1
- A larger open-label trial (n=160) confirmed patients were effectively switched from oral to short-term IV therapy at the same dosage, supporting bidirectional conversion 2, 5
- Lacosamide plasma concentrations were linearly related to dose across formulations, confirming bioequivalence 2
Practical Conversion Guidelines
- Both oral and IV formulations are available and safe for use in partial-onset seizures 1
- The conversion can occur in either direction (IV to PO or PO to IV) using the same daily dose 5, 6
- No loading dose is required when converting between formulations 1
Important Safety Considerations
- Abrupt discontinuation of lacosamide may precipitate withdrawal seizures - maintain continuous therapy during the conversion 7, 8
- Common adverse effects include dizziness, headache, somnolence, and diplopia, which are consistent across both formulations 1, 2
- Monitor for PR interval prolongation, particularly in patients with cardiac conduction abnormalities 7, 8
- Counsel patients about potential driving impairment during any dosing changes 7, 8