Table 2.

Indication, Timing, and Outcome of High Lamotrigine and Levetiracetam Serum/Plasma Drug Levels.

	Lamotrigine level	Levetiracetam level
	> 14 mg/L	≥ 80 mg/L
	(n = 597)	(n = 134)
	n (%)	n (%)
Indication for Ordering Specific Drug Level
Documented overdose (intentional or accidental)	34 (5.7 %)	3 (2.2 %)
Routine check (not related to pregnancy)	286 (47.9 %)	54 (40.3 %)
Routine check pregnancy or post-partum	10 (1.7 %)	0 (0.0 %)
Seizures	16 (2.7 %)	4 (3.0 %)
Possible symptoms of drug toxicity	200 (33.5 %)	58 (43.3 %)
Unknown	51 (8.5 %)	15 (11.2 %)
Timing of level
Peak	6 (1.0 %)	1 (0.7 %)
Trough	7 (1.2 %)	0 (0.0 %)
Other specific timing	6 (1.0 %)	1 (0.7 %)
Random/unknown	578 (96.8 %)	132 (98.5 %)
Changes in Drug Dosing
Decreased, temporarily held, or discontinued maintenance dose	172 (28.8 %)	22 (16.4 %)
Maintained maintenance dose	273 (45.7 %)	51 (38.1 %)
Increased maintenance dose	27 (4.5 %)	2 (1.5 %)
Unknown	125 (20.9 %)	59 (44.0 %)