Drug reference

Isocarboxazid

MAO Inhibitor · Antidepressant

MAO InhibitorAntidepressant

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

12 major

incl. contraindicated

PREGNANCY

Manufacturer advises avoid.

FDA category + note

Top interactionssee all 12 →

SympathomimeticsContraindicatedTextbookG&G 14e
Tyramine Containing FoodsContraindicatedTextbookG&G 14e
5ht Reuptake Inhibiting AntidepressantsSevereTextbookG&G 14e
AlbuterolSevereTextbookG&G 14e · p264

Mechanism

Isocarboxazid is an irreversible and nonselective monoamine oxidase (MAO) inhibitor, targeting both MAO-A and MAO-B isoenzymes. By inhibiting MAO, an enzyme responsible for the oxidative deamination of biogenic amines like norepinephrine, dopamine, and serotonin, it leads to an increased concentration of these neurotransmitters in the brain and other tissues, thereby exerting its pharmacological effects.

Indications

Mental depressionDepression unresponsive to other antidepressantsAnxiety states, including social anxiety and panic disorderPhobic patients and depressed patients with atypical, hypochondriacal, or hysterical featuresmajor depression (resistant to other antidepressants)

Dosing

Adult: (then started at a reduced dose) . at least 7–14 days after a tricyclic or related antidepressant (3 weeks in the case of clomipramine or imipramine) has been stopped . at least a week after an SSRI or related antidepressant (at least 5 weeks in the case of ﬂuoxetine) has been stopped Other antidepressant drugs The thioxanthene ﬂupentixol p.…

Pharmacokinetics

Onset

Delayed for 3 weeks or more

Peak effect

Maximal effect may take an additional 1 or 2 weeks

Metabolism

acetylation

Contraindications

Concurrent use of tyramine-rich foods (risk of hypertensive crisis)
Concurrent use of other antidepressants (tricyclic/related, SSRI/related, or other MAOIs) without adequate washout periods (e.g., wait 2 weeks after stopping MAOIs before starting other antidepressants; wait 7-14 days after stopping tricyclic/related antidepressants, or 3 weeks for clomipramine/imipramine, before starting MAOI; wait 1 week after stopping SSRI/related antidepressants, or 5 weeks for fluoxetine, before starting MAOI)
Concurrent use of pethidine (risk of high fever, sweating, excitation, delirium, convulsions, severe respiratory depression)

Side effects

Common

weight gainsexual dysfunction

Serious

Hepatotoxicity
Hypertensive crisis
Excitement
Hypomania
Mania
hypertensive crisis (with tyramine-containing foods or sympathomimetics)
serotonin syndrome (with 5HT reuptake inhibitors, tryptophan, substituted amphetamines)

Pregnancy & lactation

Pregnancy

Manufacturer advises avoid.

Drug interactions

Sympathomimetics

Contraindicated

Textbook

Potentially life-threatening elevation of blood pressure (hypertensive crisis).

Avoid concurrent use of MAOIs and medications containing sympathomimetic compounds.

Source: G&G 14e

Tyramine Containing Foods

Contraindicated

Textbook

Marked increases in blood pressure (hypertensive crisis).

Patients on MAOIs must avoid foods containing high levels of tyramine, such as soy products, dried meats and sausages, dried fruits, home-brewed and tap beers, red wine, pickled or fermented foods, and aged cheeses.

Source: G&G 14e

5ht Reuptake Inhibiting Antidepressants

Severe

Textbook

Serotonin syndrome, characterized by hyperthermia, muscle rigidity, myoclonus, tremors, autonomic instability, confusion, irritability, and agitation, which can progress to coma and death.

SSRIs should not be started until at least 14 days following discontinuation of treatment with an irreversible MAOI. For all SSRIs except fluoxetine, at least 14 days should pass prior to beginning treatment with an MAOI following the end of SSRI treatment. For fluoxetine, at least 5 weeks should pass. For venlafaxine, a 7-day interval is considered safe between ending MAOI therapy and starting venlafaxine. For duloxetine, a 5-day waiting period is needed before beginning MAOI treatment after ending duloxetine.

Source: G&G 14e

Albuterol

Severe

Textbook

Increased risk of adverse cardiovascular effects.

At least 2 weeks should elapse between the use of MAO inhibitors and administration of β2 agonists or other sympathomimetics.

Source: G&G 14e · p264

Anticholinergic Antiparkinsonian Drugs

Severe

Textbook

Delirium may occur.

Source: KDT 7e · p121

Bitolterol

Severe

Textbook

Increased risk of adverse cardiovascular effects.

At least 2 weeks should elapse between the use of MAO inhibitors and administration of β2 agonists or other sympathomimetics.

Source: G&G 14e · p264

Fenoterol

Severe

Textbook

Increased risk of adverse cardiovascular effects.

At least 2 weeks should elapse between the use of MAO inhibitors and administration of β2 agonists or other sympathomimetics.

Source: G&G 14e · p264

Furazolidone

Severe

Textbook

Risk of hypertensive crisis.

Source: Harrison 22e · p1743

Levalbuterol

Severe

Textbook

Increased risk of adverse cardiovascular effects.

At least 2 weeks should elapse between the use of MAO inhibitors and administration of β2 agonists or other sympathomimetics.

Source: G&G 14e · p264

Meperidine

Severe

Textbook

Serious drug interaction.

Avoid coadministration.

Source: G&G 14e

Metaproterenol

Severe

Textbook

Increased risk of adverse cardiovascular effects.

At least 2 weeks should elapse between the use of MAO inhibitors and administration of β2 agonists or other sympathomimetics.

Source: G&G 14e · p264

Methylenedioxymethamphetamine

Severe

Textbook

Serotonin syndrome, characterized by hyperthermia, muscle rigidity, myoclonus, tremors, autonomic instability, confusion, irritability, and agitation, which can progress to coma and death.

Avoid coadministration.

Source: G&G 14e