title: Effect of comedication on lamotrigine clearance in Korean epilepsy patients.
abstract: BACKGROUND
  Lamotrigine (LTG) is a widely used antiepileptic-drug (AED) for the treatment of epilepsy. We investigated the effect of AED comedication on LTG clearance in Korean patients with epilepsy.
  
  
  METHODS
  The authors reviewed the medical charts for all patients≥18years who have received LTG as monotherapy or adjunctive therapy. Data collected included LTG levels, dosage, treatment duration, concomitant AEDs and specific side effects. LTG clearance was estimated according to comedication.
  
  
  RESULTS
  A total of 580 blood samples from 548 patients were analyzed. LTG clearance in the enzyme-inducing AED (EIAED) coadministration group was the highest (0.050l/kg/h), followed by the LTG monotherapy group (0.028l/kg/h), the coadministration group of both valproate (VPA) and EIAED (0.024l/kg/h) and the VPA coadministration group (0.018l/kg/h). When LTG was administered with both VPA and EIAED, the multiple EIAED group had higher LTG clearance than the single EIAED group.
  
  
  CONCLUSIONS
  Concomitant administration of valproate reduced LTG clearance by approximately 35%, while EIAEDs increased LTG clearance by 80%. These relationships indicate the importance of considering the effects of comedication on LTG clearance when determining LTG dosage.
authors.affiliation: Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Clinical Pharmacology & Therapeutics, Samsung Medical Center, Seoul, Republic of Korea; Department of Clinical Pharmacology, Konkuk University Medical Center, Seoul, Republic of Korea.
authors.forename: Tae-Eun
authors.initials: TE
authors.lastname: Kim
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Seoul, Republic of Korea.
authors.forename: Eun Yeon
authors.initials: EY
authors.lastname: Joo
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Seoul, Republic of Korea.
authors.forename: Dae-Won
authors.initials: DW
authors.lastname: Seo
authors.affiliation: Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Department of Clinical Pharmacology & Therapeutics, Samsung Medical Center, Seoul, Republic of Korea. Electronic address: sy117.lee@samsung.com.
authors.forename: Soo-Youn
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Seoul, Republic of Korea.
authors.forename: Seung Bong
authors.initials: SB
authors.lastname: Hong
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006207:Half-Life; D006801:Humans; D000077213:Lamotrigine; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D014227:Triazines / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D014635:Valproic Acid / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use
chemical_list: D000927:Anticonvulsants; D014227:Triazines; D014635:Valproic Acid; D010672:Phenytoin; D000077213:Lamotrigine
keywords: Clearance; Comedication; Epilepsy; Korean; Lamotrigine; Pharmacokinetics