Isocarboxazid

Isocarboxazid, sold under the brand name Marplan among others, is a non-selective irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine class used as an antidepressant.^[5] Along with phenelzine and tranylcypromine, it is one of only three classical MAOIs still available for clinical use in the treatment of psychiatric disorders in the United States,^[6][7] though it is not as commonly employed in comparison to the others.^[6][7]

Isocarboxazid

Clinical data
Trade names	Marplan, Enerzer
AHFS/Drugs.com	Consumer Drug Information
MedlinePlus	a605036
Routes of administration	By mouth
ATC code	N06AF01 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) BR: Class C1 (Other controlled substances)[1] In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability	Low, peak at 1–2 h[2]
Metabolism	Liver (Carboxylesterase[3])
Metabolites	Hippuric acid[4]
Elimination half-life	1.5–4 h[2]
Excretion	Urine
Identifiers
IUPAC name N′-benzyl-5-methylisoxazole-3-carbohydrazide
CAS Number	59-63-2 Y
PubChem CID	3759
IUPHAR/BPS	7204
DrugBank	DB01247 Y
ChemSpider	3628 Y
UNII	34237V843T
KEGG	D02580 Y
ChEMBL	ChEMBL1201168 N
CompTox Dashboard (EPA)	DTXSID4023171
ECHA InfoCard	100.000.399
Chemical and physical data
Formula	C12H13N3O2
Molar mass	231.255 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C(NNCc1ccccc1)c2noc(c2)C
InChI InChI=1S/C12H13N3O2/c1-9-7-11(15-17-9)12(16)14-13-8-10-5-3-2-4-6-10/h2-7,13H,8H2,1H3,(H,14,16) Y Key:XKFPYPQQHFEXRZ-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Isocarboxazid is primarily used to treat mood and anxiety disorders. It has also been investigated in the treatment of schizophrenia,^[8] Parkinson's disease, and other dementia-related disorders.^[9]

Isocarboxazid, as well as other MAOIs, increase the levels of the monoamine neurotransmitters serotonin, dopamine, norepinephrine, epinephrine, melatonin, and phenethylamine in the brain.^[10]

Classical MAOIs, including isocarboxazid, are used only rarely due to prominent food and drug interactions and have been largely superseded by newer antidepressants such as the selective serotonin reuptake inhibitors (SSRIs). The cause of the interactions is because MAOIs inhibit the metabolism of dietary amines (e.g., tyramine) and the monoamine neurotransmitters. In combination with other drugs that increase the levels of the monoamine neurotransmitters such as the SSRIs, or with certain foods high in dietary amines such as aged cheeses, MAOIs can produce dangerous elevations of monoamine neurotransmitters resulting in potentially life-threatening syndromes such as hypertensive crisis and serotonin syndrome.

Contraindications

Isocarboxazid is contraindicated^[11][12] in certain patient populations, in combination with certain other drugs, and in combination with certain foods due to the risk of serious adverse reactions. Some notable contraindications include:

• Cerebrovascular disorders including Hypertension.
• Pheochromocytoma
• Liver disease
• Renal impairment
• Headache disorders
• Foods containing significant levels of Tyramine
• Serotonergic drugs (e.g. SSRIs, SNRIs, SMSs Dextromethorphan)
• Antihypertensive Agents
• CNS Depressants
• Certain Anesthetics agents

See also

• Hydrazine (antidepressant)