[Evaluation of the drug interaction between carbamazepine and lamotrigine in the treatment of refractory epilepsy patients].
BACKGROUND
Carbamazepine (CBZ) is a pharmacological agent used to control epileptic syndromes. In refractory epilepsy patients, however, a second anticonvulsive drug such as lamotrigine (LTG) is often added. This association can reduce the frequency of the epileptic seizures and favour control over them.


OBJECTIVE
This study was conducted to evaluate the plasma concentration of CBZ throughout a period of mono and polytherapy. Furthermore, tests were also carried out to determine whether any alterations were caused in the haematological parameters or in plasma concentrations by adding LTG to the therapy with CBZ.


METHODS
This study involved a sample of refractory epilepsy patients who were following monotherapy with CBZ and who had a wholly unsatisfactory control over their bouts of seizures. LTG was thus added to these patients' treatment in an attempt to improve their control over the seizures.


CONCLUSIONS
On ending the study, we found that LTG did not interfere with the plasma concentrations of CBZ or give rise to any kind of alteration in the haematological parameters of any of the patients. Nevertheless, one patient did break out in a rash, which shows that therapeutic monitoring may be a key tool, especially when the treatment that is prescribed includes two drugs with a narrow therapeutic range.
Pereira
L R L
LR
Facultad de Ciencias Farmacéuticas, Ribeirão Preto, Universidad de São Paulo, São Paulo, Brasil. lpereira@fcfrp.usp.br
Velasco
T R
TR
Ceiki-Sakamoto
A
A
de Carvalho
D
D
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000097:blood / Q000627:therapeutic use*; D002220:Carbamazepine / Q000097:blood / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy*; D006801:Humans; D000077213:Lamotrigine; D008875:Middle Aged; D014227:Triazines / Q000097:blood / Q000627:therapeutic use*
D000927:Anticonvulsants; D014227:Triazines; D002220:Carbamazepine; D000077213:Lamotrigine