Pharmacology Of Isocarboxazid

Indication	May be used to treat major depressive disorder.
Pharmacodynamics	Isocarboxazid is a non-selective hydrazine monoamine oxidase (MAO) inhibitor used to treat depression. In vivo and in vitro studies demonstrated inhibition of MAO in the brain, heart, and liver. Depression is a complicated disease that is not fully understood. It is thought that depression may be linked to an imbalance of chemicals within the brain. When depression occurs, there may be a decrease in the amount of chemicals released from nerve cells in the brain. These chemicals are called monoamines. Monoamines are broken down by a chemical called monoamine oxidase. Isocarboxazid prevents monoamine oxidase from breaking down the monoamines. This results in an increased amount of active monoamines in the brain. By increasing the amount of monoamines in the brain, the imbalance of chemicals thought to be caused by depression is altered. This helps relieve the symptoms of depression.
Mechanism of action	Isocarboxazid works by irreversibly blocking the action of a chemical substance known as monoamine oxidase (MAO) in the nervous system. MAO subtypes A and B are involved in the metabolism of serotonin and catecholamine neurotransmitters such as epinephrine, norepinephrine, and dopamine. Isocarboxazid, as a nonselective MAO inhibitor, binds irreversibly to monoamine oxidase–A (MAO-A) and monoamine oxidase–B (MAO-B). The reduced MAO activity results in an increased concentration of these neurotransmitters in storage sites throughout the central nervous system (CNS) and sympathetic nervous system. This increased availability of one or more monoamines is the basis for the antidepressant activity of MAO inhibitors.
Absorption	Well absorbed from the gastrointestinal tract.
Volume of distribution	Not Available
Protein binding	Not Available
Metabolism	Hepatic and rapid (by oxidation).
Route of elimination	Not Available
Half life	Not Available
Clearance	Not Available
Toxicity	Signs of overdose include severe anxiety, confusion, convulsions, cool clammy skin, severe dizziness, severe drowsiness, fast and irregular pulse, fever, hallucinations, severe headache, high or low blood pressure, hyperactive reflexes, muscle stiffness, respiratory depression or failure, slowed reflexes, sweating, severe trouble in sleeping, and unusual irritability.