Definition

An adrenergic neuron-blocking drug similar in effects to GUANETHIDINE. It is also noteworthy in being a substrate for a polymorphic cytochrome P-450 enzyme. Persons with certain isoforms of this enzyme are unable to properly metabolize this and many other clinically important drugs. They are commonly referred to as having a debrisoquin 4-hydroxylase polymorphism. Debrisoquine is an adrenergic neuron-blocking drug. Genetic and environmental factors are determinants of the interindividual and interethnic variability in drug metabolism. Thus, interethnic differences in debrisoquine hydroxylation polymorphism (Cytochrome p450, subfamily IID, polypeptide 6, CYP2D6) might be partly responsible for the variation in haloperidol disposition between races. The influence of tobacco, ethanol, caffeine, gender, and oral contraceptive use on the debrisoquine metabolic ratio (MR) has been analyzed in panels of healthy volunteers. About 5-10% of European white population has a genetically determinant defect of the CYP2D6, one of the enzymes of cytochrome P-450. This defect leads to the impaired metabolism of many drugs including various psychopharmacological agents. The measurement of the hydroxylation of debrisoquine is a laboratory test which allows identifying such an individual. Patients who show an impaired hydroxylation of debrisoquine usually demonstrate severe side effects and poor outcome of psychopharmacotherapy. In practice, knowledge of a patient's debrisoquine metabolic phenotype is an advantage when prescribing tricyclic antidepressants and neuroleptics, as the drug concentration will be considerably higher in slow metabolisers than in the average patient. (PMID: 8839686, 1738265, 7878155) [HMDB]

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Debrisoquine Interacts with Diseases

Debrisoquine Interacts with Genes