Nurses Compass
Drug Guide
Isocarboxazid
Classification
Therapeutic: Antidepressant, Monoamine oxidase inhibitor (MAOI)
Pharmacological: Irreversible monoamine oxidase inhibitor
FDA Approved Indications
- Major depressive disorder (approved for treatment-resistant depression)
Mechanism of Action
Isocarboxazid inhibits monoamine oxidase enzymes (MAO-A and MAO-B), leading to increased levels of neurotransmitters such as norepinephrine, serotonin, and dopamine in the brain, which helps improve depressive symptoms.
Dosage and Administration
Adult: Typically, 10-20 mg twice daily, titrated gradually based on response and tolerability.
Pediatric: Not approved for pediatric use.
Geriatric: Use with caution; start at lower doses due to increased risk of side effects.
Renal Impairment: Adjust dosing based on clinical response; no specific guidelines.
Hepatic Impairment: Use cautiously; monitor closely.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed; crosses the blood-brain barrier.
Metabolism: Metabolized in the liver, primarily via oxidation.
Excretion: Excreted mainly in urine.
Half Life: Approximately 3-4 hours; irreversible inhibition of MAO lasts longer.
Contraindications
- Concurrent use with other serotonergic drugs, tyramine-rich foods, or certain medications such as other MAOIs, SSRIs, SNRIs, tricyclic antidepressants, and sympathomimetics.
Precautions
- History of hypertensive crisis, liver disease, or cerebrovascular disease. Risk of hypertensive crisis if dietary restrictions are not followed.
Adverse Reactions - Common
- Dizziness (Common)
- Dry mouth (Common)
- Insomnia (Common)
Adverse Reactions - Serious
- Hypertensive crisis (Serious (rare, but potentially fatal))
- Serotonin syndrome (Serious (if combined with other serotonergic drugs))
- Liver toxicity (Rare)
Drug-Drug Interactions
- Other antidepressants, sympathomimetics, meperidine, alcohol, certain pain medications.
Drug-Food Interactions
- Tyramine-rich foods (aged cheeses, cured meats, fermented foods) can precipitate hypertensive crisis.
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor blood pressure regularly, assess for signs of hypertensive crisis, check liver function tests.
Diagnoses:
- Risk for hypertensive crisis
- Risk for serotonin syndrome
Implementation: Educate patient about dietary restrictions, monitor for adverse effects, advise about drug interactions.
Evaluation: Effectiveness of depression treatment, absence of hypertensive crises or adverse reactions.
Patient/Family Teaching
- Adhere strictly to dietary restrictions, report symptoms of hypertensive crisis (severe headache, palpitations, stiff neck), do not combine with other serotonergic drugs without medical advice.
- Do not stop medication abruptly.
- Carry medical identification indicating MAOI use.
Special Considerations
Black Box Warnings:
- Risk of hypertensive crisis with dietary tyramine and certain medications.
- Serious drug interactions can lead to serotonin syndrome.
Genetic Factors: None specifically noted.
Lab Test Interference: None known.
Overdose Management
Signs/Symptoms: Severe hypertension, hyperthermia, convulsions, coma.
Treatment: Supportive care, control blood pressure with agents like nitroprusside, gastric lavage if recent ingestion, activated charcoal.
Storage and Handling
Storage: Store at room temperature, away from moisture and heat.
Stability: Stable within specified date, check manufacturer instructions.