Related Experiment Video
Updated: Aug 15, 2026

Methods for Studying the Mechanisms of Action of Antipsychotic Drugs in Caenorhabditis elegans
Published on: February 4, 2014
Effect of carbamazepine on the pharmacokinetics of promazine
M Syrek1, J Wójcikowski, W Daniel
1Department of Pharmacokinetics and Drug Metabolism, Polish Academy of Sciences, Kraków, Poland.
Abstract:
Combinations of neuroleptics and carbamazepine are administered to psychiatric patients in the therapy of mania, manic-depressive illness and schizophrenia. The present study was aimed at assessing the influence of carbamazepine on the pharmacokinetics of promazine. Male Wistar rats received promazine and/or carbamazepine twice daily for two weeks (promazine, 10 mg/kg ip; carbamazepine, 15 mg/kg ip during the 1st, and 20 mg/kg ip during the 2nd week of treatment). In a short time (1 h) after administration, carbamazepine had a tendency to increase the concentration of promazine in the blood plasma and brain. Lineweaver-Burk's analysis showed that carbamazepine added in vitro competitively inhibited the N-demethylation of promazine in liver microsomes, without affecting the sulphoxidation process. The effect was reflected in vivo (1 h) by an increased promazine/desmethylpromazine ratio. After a long time interval (6 h, 12 h), carbamazepine decreased the concentration of promazine and its metabolites. In vitro studies into the promazine metabolism, conducted on microsomes from rats treated with promazine and/or carbamazepine, did not show acceleration of its demethylation or sulphoxidation by carbamazepine. The obtained results suggest that induction of promazine metabolism by carbamazepine involves metabolic pathways other than N-demethylation or sulphoxidation. It has been concluded that when a phenothiazine neuroleptic, such as promazine, is administered jointly with carbamazepine, a slight increase in the neuroleptic concentration may be expected in a short time after administration, followed by its significant decrease.
More Related Videos
07:02A Computerized Test Battery to Study Pharmacodynamic Effects on the Central Nervous System of Cholinergic Drugs in Early Phase Drug Development
Published on: February 11, 2019
07:35Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale
Published on: July 8, 2025
Related Concept Videos
Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...
Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance
A study on guinea pigs examined the...
Pharmacokinetics: Drug–Drug Interactions
Pharmacokinetics in Pediatric Patients: Drug Metabolism
Pharmacokinetic–Pharmacodynamic Relationship: Problems