Acetylator phenotype in relation to monoamine oxidase inhibitor antidepressant drug therapy

The MAOI antidepressant drug phenelzine has a molecular structure closely related to drugs known to be acetylated, specifically isoniazid. Acetylator phenotype is genetically determined and shows wide variation between different ethnic groups. Acetylator phenotype could be a major factor as a determinant of response to phenelzine therapy and the findings from three studies are discussed. The implications for other (non-psychotropic) drug therapy are briefly referred to.