phenelzine

ROUTE	ONSET	PEAK	DURATION
PO	2–4 wk	3–6 wk	2 wk

Contraindicated in:

Hypersensitivity;
Liver disease;
Severe renal impairment;
Pheochromocytoma;
HF;
Patients undergoing elective surgery requiring general anesthesia (should be discontinued ≥10 days before surgery);
Excessive consumption of caffeine;
Concurrent use of meperidine, SSRIs, SNRIs, tricyclic antidepressants, tetracyclic antidepressants, nefazodone, trazodone, procarbazine, selegiline, linezolid, carbamazepine, cyclobenzaprine, bupropion, buspirone, sympathomimetics, other MAO inhibitors, dextromethorphan, narcotics, alcohol, general anesthetics, diuretics, or tryptophan;
Concurrent use of foods containing high concentrations of tyramine (see Food Sources for Specific Nutrients).

Use Cautiously in:

May ↑ risk of suicide attempt/ideation especially during early treatment or dose adjustment; this risk appears to be greater in adolescents or children;
Schizophrenia;
Bipolar disorder;
Seizure disorders;
Diabetes (↑ risk of hypoglycemia);
OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Pedi: Safety and effectiveness not established in children;
Geri: ↑risk of adverse reactions in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: edema, orthostatic hypotension, HYPERTENSIVE CRISIS

Derm: pruritus, rash

EENT: blurred vision, glaucoma, nystagmus

F and E: hypernatremia

GI: constipation, dry mouth, ↑liver enzymes, abdominal pain, nausea, vomiting

GU: sexual dysfunction, urinary retention

Metab: weight gain

Neuro: dizziness, drowsiness, fatigue, headache, hyperreflexia, insomnia, tremor, twitching, weakness, euphoria, paresthesia, restlessness, SEIZURES, SUICIDAL THOUGHTS/BEHAVIORS

Interactions ⬆ ⬇

Drug-drug:

Serious, potentially fatal adverse reactions may occur with concurrent use of other antidepressants (SSRIs, SNRIs, bupropion, tricyclics, tetracyclics, nefazodone, trazodone), carbamazepine, cyclobenzaprine, procarbazine, or selegiline. Avoid using within 2 wk of each other (wait 5 wk from end of fluoxetine therapy).
Hypertensive crisis may occur with amphetamines, levodopa, dopamine, epinephrine, norepinephrine, methylphenidate, or vasoconstrictors.
Hypertension or hypotension, coma, seizures, respiratory depression, and death may occur with meperidine; avoid using within 2–3 wk of MAO inhibitor therapy.
Dextromethorphan may produce psychosis or bizarre behavior.
Hypertension may occur with buspirone; avoid using within 2 wk of each other.
Additive hypotension may occur with antihypertensives, spinal anesthesia, opioids, or barbiturates.
Additive hypoglycemia may occur with insulins or oral hypoglycemic agents.
Risk of seizures may be ↑ with tramadol.

Drug-Natural Products:

Serious, potentially fatal adverse effects (serotonin syndrome) may occur with St. John's wort and SAMe.
Hypertensive crises may occur with large amounts of caffeine-containing herbs (cola nut, guarana, or malt).
Insomnia, headache, tremor, hypomania may occur with ginseng.
Hypertensive crises, disorientation, and memory impairment may occur with tryptophan or supplements containing tyrosine or phenylalanine.

Drug-Food:

Hypertensive crisis may occur with ingestion of foods containing high concentrations of tyramine (see Food Sources for Specific Nutrients).
Consumption of foods or beverages with high caffeine content ↑ the risk of hypertension and arrhythmias.

Route/Dosage ⬆ ⬇

PO (Adults ): 15 mg 3 times daily; ↑ to 60–90 mg/day in divided doses; after maximal benefit achieved, gradually ↓ to smallest effective dose (15 mg/day or every other day).

Availability ⬆ ⬇

Assessment ⬆ ⬇

Assess mental status, mood changes, and anxiety level frequently.
Monitor BP and HR before and frequently during therapy.
Monitor intake and output and daily weight. Assess patient for peripheral edema and urinary retention.
Assess for suicidal tendencies, especially during early therapy. Restrict amount of drug available to patient. Risk may be ↑ in adults ≤24 yr. After starting therapy, young adults should be seen by health care provider face-to-face at least weekly for 4 wk, then every other wk for next 4 wk, then at 12 wk, and then on advice of health care provider thereafter.

Lab Test Considerations:

Assess hepatic function periodically during prolonged or high-dose therapy.
- Monitor serum glucose closely in patients with diabetes; hypoglycemia may occur.

Toxicity and Overdose:

Concurrent ingestion of tyramine-rich foods and many medications may result in a life-threatening hypertensive crisis. Signs and symptoms of hypertensive crisis include chest pain, tachycardia or bradycardia, severe headache, nausea, vomiting, photosensitivity, neck stiffness, sweating, and enlarged pupils. Treatment includes IV phentolamine.
- Symptoms of overdose include anxiety, irritability, tachycardia, hypertension or hypotension, respiratory distress, dizziness, drowsiness, hallucinations, confusion, seizures, sluggish reflexes, fever, and diaphoresis. Treatment includes induction of vomiting or gastric lavage and supportive therapy as symptoms arise.

Implementation ⬆ ⬇

Do not administer these medications in the evening because the psychomotor stimulating effects may cause insomnia or other sleep disturbances.
PO: Tablets may be crushed and mixed with food or fluids for patients with difficulty swallowing.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed. Take missed doses if remembered within 2 hr; otherwise, omit and return to regular dosage schedule. Do not discontinue abruptly as withdrawal symptoms (nausea, vomiting, malaise, nightmares, agitation, psychosis, seizures) may occur.
Caution patient to avoid alcohol, CNS depressants, OTC drugs, and foods or beverages containing tyramine (see Food Sources for Specific Nutrients) or excessive caffeine during and for ≥2 wk after therapy has been discontinued; they may precipitate a hypertensive crisis. Instruct patient to notify health care provider immediately if symptoms of hypertensive crisis (severe headache, palpitations, chest or throat tightness, sweating, dizziness, neck stiffness, nausea, vomiting) develop.
Advise patient, family, and caregivers to look for suicidality, especially during early therapy or dose changes. Notify health care provider immediately if thoughts about suicide or dying, attempts to commit suicide, new or worse depression or anxiety, agitation or restlessness, panic attacks, insomnia, new or worse irritability, aggressiveness, acting on dangerous impulses, mania, or other changes in mood or behavior.
May cause dizziness or drowsiness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
Caution patient to change positions slowly to minimize orthostatic hypotension. Older adults are at ↑ risk for this side effect.
Instruct patient to consult with health care provider before taking any new prescription, OTC, or herbal product.
Advise patient to notify health care provider if dry mouth, urinary retention, or constipation occurs. Frequent rinses, good oral hygiene, and sugarless candy or gum may ↓ dry mouth. An ↑ in fluid intake, fiber, and exercise may prevent constipation.
Advise patient to notify health care provider of medication regimen before surgery. If possible, therapy should be discontinued at least 2 wk before surgery.
Instruct patient to carry identification describing medication regimen at all times.
Emphasize the importance of participation in psychotherapy if recommended by health care provider and follow-up exams to evaluate progress. Ophthalmologic testing should also be done periodically with long-term therapy.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇

Time/Action Profile ⬆ ⬇

Contraind./Precautions ⬆ ⬇