FEN-el-zeen

Therapeutic Classification: antidepressants

Pharmacologic Classification: monamine oxidase inhibitors

• Treatment of neurotic or atypical depression (usually reserved for patients who do not tolerate or respond to other modes of therapy [e.g. tricyclic antidepressants, SSRIs, SSNRIs or electroconvulsive therapy]).

• Inhibits the enzyme monoamine oxidase, resulting in an accumulation of various neurotransmitters (dopamine, epinephrine, norepinephrine, and serotonin) in the body.

• Improved mood in depressed patients.

Absorption: Well absorbed from the GI tract.

Distribution: Crosses the placenta and probably enters breast milk.

Metabolism/Excretion: Metabolized by the liver; excreted in urine as metabolites and unchanged drug.

Half-life: 12 hr.

(antidepressant effect)

Contraindicated in:

• Hypersensitivity
• Liver disease
• Severe renal disease
• Pheochromocytoma
• Heart failure
• Patients undergoing elective surgery requiring general anesthesia (should be discontinued at least 10 days before surgery)
• Excessive consumption of caffeine
• Concurrent use of meperidine, SSRI antidepressants, SSNRI antidepressants, 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 Appendix M)
• Lactation.

Use Cautiously in:

• Patients who may be suicidal or have a history of drug dependency
• Pedi: May ↑ risk of suicide attempt/ideation especially during first 1–2 mo of treatment or with dose adjustments
• Schizophrenia
• Bipolar disorder
• Seizure disorders
• Diabetes (↑ risk of hypoglycemia)
• Geri: Geriatric patients (↑ risk of adverse reactions)
• Pregnancy (safety not established)Children (safety and effectiveness not established).

CV: edema, orthostatic hypotension, HYPERTENSIVE CRISIS.

Derm: pruritis, rashes.

EENT: blurred vision, glaucoma, nystagmus.

Endo: weight gain.

F and E: hypernatremia.

GI: constipation, dry mouth, abdominal pain, liver function test elevation, nausea, vomiting.

GU: sexual dysfunction, urinary retention.

Neuro: dizziness, drowsiness, fatigue, headache, hyperreflexia, insomnia, tremor, twitching, weakness, euphoria, paresthesia, restlessness, SEIZURES.

Drug-Drug:

• Serious, potentially fatal adverse reactions may occur with concurrent use of other antidepressants (SSRIs, SSNRIs, 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).
• Concurrent use with dextromethorphanmay produce psychosis or bizarre behavior.
• Hypertension may occur with concurrent use of 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 concomitant use of 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 Appendix M).
• Consumption of foods or beverages with high caffeine content increases the risk of hypertension and arrhythmias.

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

• Tablets: 15 mg;

• Assess mental status, mood changes, and anxiety level frequently. Assess for suicidal tendencies, especially during early therapy. Restrict amount of drug available to patient.
• Monitor BP and pulse rate before and frequently during therapy. Report significant changes promptly.
• Monitor intake and output ratios and daily weight. Assess patient for peripheral edema and urinary retention.

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

• 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.

• 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.

• 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 Appendix M) or excessive caffeine during and for at least 2 wk after therapy has been discontinued; they may precipitate a hypertensive crisis. Instruct patient to notify health care professional immediately if symptoms of hypertensive crisis (e.g. severe headache, palpitations, chest or throat tightness, sweating, dizziness, neck stiffness, nausea, or vomiting) develop.
• Instruct parents or guardians of children to contact health care professional immediately if child exhibits any suicidal thoughts or behaviors (e.g. worsening depression, new or worsening anxiety, agitation, panic attacks, insomnia, new or worsening irritability, violent behavior, impulsive actions, excessive talking, unusual 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. Geriatric patients are at increased risk for this side effect.
• Instruct patient to consult with health care professional before taking any new prescription, OTC, or herbal product.
• Advise patient to notify health care professional if dry mouth, urinary retention, or constipation occurs. Frequent rinses, good oral hygiene, and sugarless candy or gum may diminish dry mouth. An increase in fluid intake, fiber, and exercise may prevent constipation.
• Advise patient to notify health care professional 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 professional and follow-up exams to evaluate progress. Ophthalmologic testing should also be done periodically with long-term therapy.

• Improved mood in depressed patients.
  • Decreased anxiety.
  • Increased appetite.
  • Improved energy level.
  • Improved sleep.
  • Patients may require 3–6 wk of therapy before therapeutic effects of medication are seen.

Nardil