vilazodone

(vil-az-oh-done) vilazodone,

Viibryd

(trade name)

Classification

Therapeutic: antidepressants
Pharmacologic: selective serotonin reuptake inhibitors ssris
Pregnancy Category: C

Indications

Treatment of major depressive disorder.

Action

Increases serotonin activity in the CNS by inhibiting serotonin reuptake. Also binds selectively with high affinity to 5-HT_1A receptors and is a 5-HT_1A receptor partial agonist.

Therapeutic effects

Improvement in symptoms of depression.

Pharmacokinetics

Absorption: 72% absorbed following oral administration with food.Distribution: Unknown.Protein Binding: 96–99%.Metabolism and Excretion: Mostly metabolized by the liver, primarily by the CYP3A4 enzyme system; 1% excreted unchanged in urine.Half-life: 25 hr.

Time/action profile (blood levels)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	4–5 hr	unknown

Contraindications/Precautions

Contraindicated in: Concurrent use of MAO inhibitors or MAO-like drugs (linezolid or methylene blue);Severe hepatic impairment.Use Cautiously in: History of seizure disorder;History of suicide attempt/suicidal ideation;Bipolar disorder; may ↑ risk of mania/hypomania; Obstetric: Use only if maternal benefit outweighs fetal risk; use during third trimester may result in need for prolonged hospitalization, respiratory support and tube feeding; Lactation: Breast feed only if maternal benefit outweighs newborn risk; Pediatric: Safety and effectiveness not established; ↑ risk of suicidal thinking/behavior in children, adolescents and young adults.

Adverse Reactions/Side Effects

Central nervous system

neuroleptic malignant-like syndrome (life-threatening)
seizures (life-threatening)
suicidal thoughts (life-threatening)
insomnia (most frequent)
abnormal dreams
dizziness

Gastrointestinal

diarrhea (most frequent)
nausea (most frequent)
dry mouth
restlessness
vomiting

Endocrinologic

↓ libido
sexual dysfunction
syndrome of inappropriate antidiuretic hormone (SIADH)

Fluid and Electrolyte

hyponatremia

Hematologic

bleeding

Miscellaneous

serotonin syndrome (life-threatening)

Interactions

Drug-Drug interaction

Concurrent use with, or use within 14 days of starting or stopping MAOIs may ↑ risk of neuroleptic malignant syndrome or serotonin syndrome and should be avoided.Concurrent use with MAO-inhibitor like drugs, such as linezolid or methylene blue may ↑ risk of serotonin syndrome; concurrent use contraindicated; do not start therapy in patients receiving linezolid or methylene blue ; if linezolid or methylene blue need to be started in a patient receiving vilazodone, immediately discontinue vilazodone and monitor for signs/symptoms of serotonin syndrome for 2 wk or until 24 hr after last dose of linezolid or methylene blue, whichever comes first (may resume vilazodone therapy 24 hr after last dose of linezolid or methylene blue)Drugs that affect serotonergic neurotransmitter systems, including tricyclic antidepressants, SNRIs, fentanyl, buspirone, tramadol and triptans ↑ risk of serotonin syndromeConcurrent use with NSAIDs, aspirin, antiplatelet drugs, or other drugs that affect coagulation may ↑ risk of bleeding.Concurrent use of strong inhibitors of CYP3A4, including ketoconazole ↑ blood levels and the risk of adverse reactions/toxicity; daily dose should not exceed 20 mg.Concurrent use of moderate inhibitors of CYP3A4, including erythromycin may require dose ↓ to 20 mg daily if adverse reactions/toxicity occurs.Use cautiously with other CNS-active drugs.

Route/Dosage

Oral (Adults) 10 mg once daily for one week, then 20 mg once daily for one week, then 40 mg once daily. Concurrent use of strong inhibitors of CYP3A4—daily dose should not exceed 20 mg.

Availability

Tablets: 10 mg, 20 mg, 40 mg

Nursing implications

Nursing assessment

Assess mental status and mood changes. Inform health care professional if patient demonstrates significant ↑ in anxiety, nervousness, or insomnia.
Prior to starting therapy, screen patient for bipolar disorder (detailed psychiatric history, including family history of suicide, bipolar disorder, depression). Use cautiously in patients with a positive history.
Assess suicidal tendencies, especially in early therapy. Restrict amount of drug available to patient. Risk may be ↑ in children, adolescents, and adults ≤24 yr.
Assess for signs and symptoms of hyponatremia (headache, difficulty concentrating, memory impairment, confusion, weakness, unsteadiness). May require discontinuation of therapy.
Assess for serotonin syndrome (mental changes [agitation, hallucinations, coma], autonomic instability [tachycardia, labile BP, hyperthermia], neuromuscular aberrations [hyper-reflexia, incoordination], and/or GI symptoms [nausea, vomiting, diarrhea]), especially in patients taking other serotonergic drugs (SSRIs, SNRIs, triptans).
Monitor for development of neuroleptic malignant syndrome (fever, muscle rigidity, altered mental status, respiratory distress, tachycardia, seizures, diaphoresis, hypertension or hypotension, pallor, tiredness, loss of bladder control). Discontinue vilazodone and notify health care professional immediately if these symptoms occur.
Lab Test Considerations: Monitor serum sodium concentrations periodically during therapy. May cause hyponatremia potentially as a result of syndrome of inappropriate antidiuretic hormone secretion (SIADH).
- May cause altered anticoagulant effects. Monitor patients receiving warfarin, NSAIDs, or aspirin concurrently.

Potential Nursing Diagnoses

Ineffective coping (Indications)
Risk for injury (Side Effects)

Implementation

Oral: Administer vilazodone with food; administration without food can result in inadequate drug concentrations and may ↓ effectiveness.

Patient/Family Teaching

Instruct patient to take vilazodone as directed at the same time each day. Take missed doses as soon as possible unless almost time for next dose. Do not double doses or discontinue abruptly. Gradually ↓ dose before discontinuation. Advise patient to read Medication Guide before starting therapy and with each Rx refill; new information may be available.
Advise patient, family, and caregivers to look for activation of maina/hypomania and suicidality, especially during early therapy or dose changes. Notify health care professional 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 or if symptoms of serotonin syndrome occur.
Caution patient of the risk of serotonin syndrome and neuroleptic malignant syndrome, especially when taking triptans, tramadol, tryptophan supplements and other serotonergic or antipsychotic agents.
May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to the drug is known.
Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to avoid concurrent use of Rx, OTC, and herbal products, especially NSAIDs, aspirin, and warfarin, without consulting health care professional.
Caution patient to avoid taking alcohol or other CNS-depressant drugs during therapy.
Instruct female patients to inform health care professional if pregnancy is planned or suspected or if breast feeding.
Emphasize the importance of follow-up exams to monitor progress. Encourage patient participation in psychotherapy.

Evaluation/Desired Outcomes

↑ sense of well-being.
- Renewed interest in surroundings. Need for therapy should be periodically reassessed. Therapy is usually continued for several months.
↓ anxiety.