The SSRIs act as antidepressants by inhibiting CNS neuronal uptake of serotonin with little or no effect on norepinephrine; they are also thought to antagonize muscarinic, histaminergic, and alpha1-adrenergic receptors. The increase in serotonin levels at neuroreceptors is thought to act as a stimulant, counteracting depression and increasing motivation.

Indications

Treatment of depression; most effective in patients with major depressive disorder (SSRIs)

Adverse effects

in italics are most common; those in bold are life-threatening. U Do not crush.

Treatment of OCD, PTSD, social anxiety, generalized anxiety disorder, panic disorder, PMDD

Unlabeled uses: Treatment of bulimia

Contraindications and cautions

Contraindicated with hypersensitivity to any SSRI; pregnancy.

Use cautiously with impaired hepatic or renal function, diabetes mellitus, lactation.

Adverse effects

CNS: Headache, nervousness, insomnia, drowsiness, anxiety, tremor, dizziness, light-headedness, agitation, sedation, abnormal gait, seizures

CV: Hot flashes, palpitations

Dermatologic: Sweating, rash, pruritus,acne, alopecia, contact dermatitis

GI: Nausea, vomiting, diarrhea, dry mouth, anorexia, dyspepsia, constipation, taste changes, flatulence, gastroenteritis, dysphagia, gingivitis

GU: Painful menstruation, sexual dysfunction,frequency, cystitis, impotence, urgency, vaginitis

Respiratory: URIs, pharyngitis, cough, dyspnea, bronchitis, rhinitis

Other: Weight loss, asthenia, fever

Interactions

Drug-drug

Increased therapeutic and toxic effects of TCAs with SSRIs

Decreased therapeutic effects with cyproheptadine

Risk for severe to fatal hypertensive crisis with MAOIs; avoid this combination ?Drug-alternative therapy

Increased risk of severe reaction with St. John’s Wort

Nursing considerations

Assessment

History: Hypersensitivity to any SSRI; impaired hepatic or renal function; diabetes mellitus; lactation; pregnancy

Physical: Weight; T; rash, lesions; reflexes, affect; bowel sounds, liver evaluation; P, peripheral perfusion; urinary output; LFTs, renal function tests, CBC

Interventions

Arrange for lower dose or less frequent administration in elderly patients and patients with hepatic or renal impairment.

Establish suicide precautions for severely depressed patients. Dispense only a small number of capsules at a time to these patients.

Black box

warning Monitor children, adolescents, and young adults for suicidal thoughts and behavior, especially when changing dosage.

Administer drug in the morning. If dose of more than 20 mg/day is needed, adminis- ter in divided doses.

Monitor patient response for up to 4 wk before increasing dose because of lack of therapeutic effect. It frequently takes several weeks to see the desired effect.

Provide frequent small meals if GI upset or anorexia occurs. Monitor weight loss; a nutritional consultation may be needed.

Provide sugarless candies, frequent mouth care if dry mouth is a problem.

Ensure ready access to bathroom facilities if diarrhea occurs. Establish bowel program if constipation is a problem.

Establish safety precautions (use side rails, appropriate lighting; accompany patient) if CNS effects occur.

Provide appropriate comfort measures if CNS effects, insomnia, rash, sweating occur.

Encourage patient to maintain therapy for treatment of underlying cause of depression.

Teaching points

It may take up to 4 weeks to get a full antidepressant effect from these drugs. These drugs should be taken in the morning (or in divided doses if necessary).

Do not take these drugs during pregnancy. If you think that you are pregnant or you wish to become pregnant, consult your health care provider.

You may experience these side effects: Dizziness, drowsiness, nervousness, insomnia (avoid driving or performing hazardous tasks); nausea, vomiting, weight loss (frequent small meals may help; monitor your weight loss—if it becomes marked, consult your health care provider); sexual dysfunction (drug effect); flulike symptoms (if severe, consult your health care provider for appropriate treatment); photosensitivity (avoid exposure to sunlight).

Report rash, mania, seizures, severe weight loss.

Representative drugs

citalopram

desvenlafaxine

escitalopram

fluoxetine

fluvoxamine

paroxetine

sertraline

venlafaxine

vilazodone