J Korean Soc Biol Psychiatry.
2000 Jul;7(1):14-20.
Drug Interaction in New Antipsychotics
Abstract
- Recently atypical antipsychotics have been used as first line agent in the treatment of schizophrenia, and also played a significant role in the treatment of many kinds of psychiatric disorders. The pharmacokinetic and pharmacodynamic properties of these newer antipsychotics are well know through preclinical and early clinical trials. However, it is important to note the limitations of the results due to its relatively short experience. Clozapine is eliminated principally by the hepatic P450 1A2 and 3A4 cytochrome enzymes. 1A2 inducers such as carbamazepine and smoking can reduce its half-life, while 1A2 inhibitors such as SSRIs especially fluvoxamine can increase its duration of action. Carbamazepine should be avoided in a patient on clozapine because of carbamazepine's potential effects on bone marrow. Benzodiazepines tend to increase the chances of sedation delirium and respiratory depression. Risperidone is metabolized to 9-hydroxyriperidone by the hepatic P450 2D6 cytochrome enzymes. Fluoxetine and paroxetine, 2D6 inhibitors interfere with metabolism, but 9-hydroxyrisperidone has similar biological activity as parental drug, so it has little affect on the outcome. Olanzapine shows minimal capacity to inhibit cytochrome P450 isoenzymes and shows minimal chance of drug interaction. It is eliminated principally by the hepatic P450 1A2 and 2D6 cytochrome enzymes.
MeSH Terms
-
Antipsychotic Agents*
Benzodiazepines
Bone Marrow
Carbamazepine
Clozapine
Cytochrome P-450 Enzyme System
Cytochromes
Delirium
Drug Interactions*
Fluoxetine
Fluvoxamine
Half-Life
Humans
Isoenzymes
Metabolism
Parents
Paroxetine
Respiratory Insufficiency
Risperidone
Schizophrenia
Smoke
Smoking
Antipsychotic Agents
Benzodiazepines
Carbamazepine
Clozapine
Cytochrome P-450 Enzyme System
Cytochromes
Fluoxetine
Fluvoxamine
Isoenzymes
Paroxetine
Risperidone
Smoke
