PHARMACOLOGIC PROFILE
General Use
Used in the treatment of various forms of endogenous depression, often in conjunction with psychotherapy.
Other uses include: Treatment of anxiety (doxepin, fluoxetine, paroxetine, sertraline,
venlafaxine); Enuresis (imipramine); Chronic pain syndromes (amitriptyline, doxepin,
imipramine, nortriptyline); Smoking cessation (bupropion); Bulimia (fluoxetine); Obsessivecompulsive
disorder (fluoxetine, fluvoxamine, paroxetine, sertraline); Social anxiety disorder
(paroxetine, sertraline).
General Action and Information
Antidepressant activity is most likely due to preventing the reuptake of dopamine, norepinephrine,
and serotonin by presynaptic neurons, resulting in accumulation of these neurotransmitters.
The two major classes of antidepressants are the tricyclic antidepressants and the SSRIs.
Most tricyclic agents possess significant anticholinergic and sedative properties, which explains
many of their side effects (amitriptyline, amoxapine, doxepin, imipramine, nortriptyline). The
SSRIs are more likely to cause insomnia (fluoxetine, fluvoxamine, paroxetine, sertraline).
Contraindications
Hypersensitivity. Should not be used in narrow-angle glaucoma. Should not be used in pregnancy
or lactation or immediately after MI.
Precautions
Use cautiously in older patients and those with pre-existing cardiovascular disease. Elderly men
with prostatic enlargement may be more susceptible to urinary retention. Anticholinergic side
effects of tricyclic antidepressants (dry eyes, dry mouth, blurred vision, and constipation) may
require dosage modification or drug discontinuation. Dosage requires slow titration; onset of
therapeutic response may be 2-4 wk. May decrease seizure threshold, especially bupropion.
Interactions
Tricyclic antidepressants—May cause hypertension, tachycardia, and convulsions when
used with MAO inhibitors. May prevent therapeutic response to some antihypertensives. Additive
CNS depression with other CNS depressants. Sympathomimetic activity may be enhanced when
used with other sympathomimetics. Additive anticholinergic effects with other drugs possessing anticholinergic properties. MAO inhibitors—Hypertensive crisis may occur with concurrent
use of MAO inhibitors and amphetamines, methyldopa, levodopa, dopamine, epinephrine, norepinephrine,
desipramine, imipramine, reserpine, vasoconstrictors, or ingestion of tyraminecontaining
foods. Hypertension or hypotension, coma, convulsions, and death may occur with
meperidine or other opioid analgesics and MAO inhibitors. Additive hypotension with antihypertensives
or spinal anesthesia and MAO inhibitors. Additive hypoglycemia with insulin or
oral hypoglycemic agents and MAO inhibitors. SSRIs, bupropion, or venlafaxine should not be
used in combination with or within weeks of MAO inhibitors (see individual monographs). Risk
of adverse reactions may be increased by almotriptan, frovatriptan, rizatriptan, naratriptan, sumatriptan,
or zolmitriptan.
NURSING IMPLICATIONS
Assessment
● Monitor mental status and affect. Assess for suicidal tendencies, especially during early therapy.
Restrict amount of drug available to patient.
● Toxicity and Overdose: Concurrent ingestion of MAO inhibitors and tyramine-containing foods
may lead to hypertensive crisis. Symptoms include chest pain, severe headache, nuchal rigidity,
nausea and vomiting, photosensitivity, and enlarged pupils. Treatment includes IV phentolamine.
Potential Nursing Diagnoses
● Ineffective coping (Indications).
● Risk for injury (Side Effects).
● Deficient knowledge, related to disease process and medication regimen (Patient/Family
Teaching).
Implementation
● Administer drugs that are sedating at bedtime to avoid excessive drowsiness during waking
hours, and administer drugs that cause insomnia (fluoxetine, fluvoxamine, paroxetine, sertraline,
MAO inhibitors) in the morning.
Patient/Family Teaching
● Caution patient to avoid alcohol and other CNS depressants. Patients receiving MAO inhibitors
should also avoid OTC drugs and foods or beverages containing tyramine (see Appendix M)
during and for at least 2 wk after therapy has been discontinued, as they may precipitate a hypertensive
crisis. Health care professional should be contacted immediately if symptoms of
hypertensive crisis develop.
● Inform patient that dizziness or drowsiness may occur. Caution patient to avoid driving and
other activities requiring alertness until response to the drug is known.
● Caution patient to make position changes slowly to minimize orthostatic hypotension.
● 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 and any herbal alternative
therapies before treatment or surgery. MAO inhibitor therapy usually needs to be withdrawn
at least 2 wk before use of anesthetic agents.
● Emphasize the importance of participation in psychotherapy and follow-up exams to evaluate
progress.
Evaluation/Desired Outcomes
● Resolution of depression.
● Decrease in anxiety.
● Control of bedwetting in children over 6 yr of age.
● Management of chronic neurogenic pain.
