Home Drug Guide Phenelzine Sulfate

Drug Guide

Generic Name

Phenelzine Sulfate

Brand Names Nardil

Classification

Therapeutic: Antidepressant, Monoamine Oxidase Inhibitor (MAOI)

Pharmacological: Irreversible monoamine oxidase inhibitor

FDA Approved Indications

  • Major depressive disorder, typically when other antidepressants have failed

Mechanism of Action

Phenelzine irreversibly inhibits monoamine oxidase enzymes (MAO-A and MAO-B), leading to increased levels of monoamine neurotransmitters (serotonin, norepinephrine, dopamine) in the central nervous system, which helps alleviate depressive symptoms.

Dosage and Administration

Adult: Initially 30 mg/day in divided doses, titrated up to 60-90 mg/day as needed, in divided doses

Pediatric: Not approved for pediatric use

Geriatric: Start at lower doses with cautious titration due to increased sensitivity and potential interactions

Renal Impairment: Use with caution; dose adjustments not well established

Hepatic Impairment: Start at lower doses and monitor closely

Pharmacokinetics

Absorption: Well absorbed orally

Distribution: Widely distributed in body tissues including the brain

Metabolism: Biotransformed in the liver, with active metabolites

Excretion: Renal excretion of metabolites

Half Life: Approximately 11 hours; irreversible enzyme inhibition means effect lasts longer than the drug’s presence in plasma

Contraindications

  • Concurrent use with other serotonergic or sympathomimetic drugs
  • History of hypersensitivity to phenelzine or other MAOIs
  • Acute cerebrovascular accident

Precautions

  • Risk of hypertensive crisis with tyramine-rich foods or certain medications; contraindicated in patients with hepatic impairment, severe cardiovascular disease, or psychiatric conditions prone to agitation or psychosis

Adverse Reactions - Common

  • Dizziness, headache, dry mouth (Common)
  • Sedation or insomnia (Common)
  • Weight gain (Common)

Adverse Reactions - Serious

  • Hypertensive crisis (due to tyramine or other vasoactive substances) (Serious)
  • Serotonin syndrome (when combined with other serotonergic agents) (Serious)
  • Orthostatic hypotension (Serious)
  • Liver toxicity (rare) (Rare)

Drug-Drug Interactions

  • SSRIs, SNRIs, tryptophan, other antidepressants (risk of serotonin syndrome)
  • Sympathomimetic agents (e.g., pseudoephedrine)

Drug-Food Interactions

  • Tyramine-rich foods (aged cheese, cured meats, fermented foods) leading to hypertensive crisis

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure regularly, hepatic function, and mental status; assess for symptoms of serotonin syndrome or hypertensive crisis.

Diagnoses:

  • Risk for hypertensive crisis
  • Risk for serotonin syndrome

Implementation: Educate patient on dietary restrictions, medication adherence, and recognizing adverse effects.

Evaluation: Assess for stabilization of depressive symptoms, blood pressure control, and absence of adverse effects.

Patient/Family Teaching

  • Avoid tyramine-rich foods and certain medications (e.g., certain decongestants, other antidepressants) during therapy.
  • Report symptoms of hypertensive crisis (severe headache, neck stiffness, rapid heartbeat) immediately.
  • Adhere strictly to medication dosing schedule and dietary restrictions.

Special Considerations

Black Box Warnings:

  • Serious, sometimes fatal, interactions with other serotonergic drugs or foods leading to hypertensive crisis or serotonin syndrome

Genetic Factors: Genetic variability in monoamine oxidase activity may influence response and side effects.

Lab Test Interference: Possible interference with liver function tests.

Overdose Management

Signs/Symptoms: Severe hypertension, hyperthermia, seizures, altered mental status

Treatment: Supportive care; manage hypertensive crisis with appropriate antihypertensives; activated charcoal if recent ingestion; avoid sympathomimetic drugs.

Storage and Handling

Storage: Store at room temperature away from moisture, heat, and light

Stability: Stable under proper storage conditions for the duration of the labeled expiry date.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.