Systematic (IUPAC) name
Clinical data
Trade names Marplan
AHFS/ Consumer Drug Information
MedlinePlus a605036
Pregnancy cat. C (USA)
Legal status Prescription only
Routes Oral
Pharmacokinetic data
Bioavailability  ?
Metabolism Liver
Half-life  ?
Excretion Urine
CAS number 59-63-2 YesY
ATC code N06AF01
PubChem CID 3759
DrugBank DB01247
ChemSpider 3628 YesY
UNII 34237V843T YesY
KEGG D02580 YesY
Chemical data
Formula C12H13N3O2 
Mol. mass 231.25
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Isocarboxazid (Enerzer, Marplan, Marplon) is an irreversible and nonselective monoamine oxidase inhibitor (MAOI) of the hydrazine chemical class used as an antidepressant and anxiolytic.[1] It is one of the few hydrazine MAOIs still in clinical use, along with phenelzine.

Isocarboxazid is used to combat numerous medical problems, such as: depression, social anxiety, panic disorder and also is in the process of becoming a medication to aid in the fight against Parkinson’s and other dementia-related disorders [2]. Although medicinally helpful to people in need, Isocarboxazid has many side effects, including: headaches, jaundice, chest pain, rapid swelling and weight gain, fainting, dizziness and tremors [2]. Isocarboxazid is from a class of medications called Monoamine Oxidase Inhibitors (MAOIs). MAOIs, Isocarboxazid included, increase the levels of biogenic amine neurotransmitters found within the brain and also increase the availability of these neurotransmitters [2].

Isocarboxazid is not used as frequently as other medications for depression and anxiety because it is extremely powerful and also reacts to certain foods, such as tyramine, because it inhibits the catabolism of dietary amines found within everyday foods [2]. Isocarboxazid and other MAOIs are often looked at as a “last resort” medication due to their reactions to foods and powerful contents. It has been used off-label to treat depersonalization disorder.


See the following for synthesis directions:

  • Gardner, Thomas S.; Wenis, E.; Lee, John (1960). "Monoamine Oxidase Inhibitors--I. 1-Alkyl and 1-Aralkyl-2-(picolinoyl and 5-methyl-3-isoxazolylcarbonyl)hydrazines". Journal of Medicinal Chemistry 2: 133. doi:10.1021/jm50009a002.  edit
  • R.E. Tedeschi, U.S. Patent 2,997,422 (1961).

See also


2. Volz, Hanz-Peter. (November 1998) “Monoamine Oxidase Inhibitors A Perspective on Their Use in The Elderly” Biochemical pharmacology (5) 341-352.