Levetiracetam
(2S)-2-(2-oxopyrrolidin-1-yl)butanamide

十六歲以上病患之局部癲癇發作(併有或不併有次發性全身發作)之單獨治療。
四歲以上孩童或成人病患之局部癲癇發作(併有或不併有次發性全身發作)，十二歲以上青少年與成人病患之肌抽躍性癲癇發作，以及十六歲以上青少年與成人患有體質性泛發性癲癇的原發性泛發性強直陣攣發作之輔助治療。

Absorption
T max is 1 h. Oral bioavailability is 100%. Food does not affect the extent of absorption, but it can decrease C max 20% and delay T max 1.5 h. Steady state is achieved after 2 days of multiple, twice-daily dosing.

Distribution
Kinetics are linear over dose range of 500 to 5,000 mg. Less than 10% is protein bound.

Metabolism
Not extensively metabolized. Major metabolic pathway is the enzymatic hydrolysis of the acetamide group, which produces the carboxylic acid metabolite ucb L057.

Elimination
Plasma t ½ is approximately 7 h. It is eliminated from the systemic circulation by renal excretion as unchanged drug, which represents 66% of dose.

Special Populations
Renal Function Impairment
Total body Cl decreases 40% in patients with CrCl 50 to 80 mL/min, 50% in patients with CrCl 30 to 50 mL/min, and 60% in patients with CrCl less than 30 mL/min. Dosage reduction is recommended.

Hepatic Function Impairment
Severe (Child-Pugh class C)
Total body Cl decreases 50%. No dosage adjustment is needed.

Elderly
Total body Cl decreased 38%; t ½ was 2.5 h longer.

Children
Cl was approximately 40% higher (children 6 to 12 yr of age).

Gender
C max and AUC are 20% higher in women.