NEFAZODONE (nef-a-zo'done)
Classifications: psychotherapeutic agent; antidepressant; selective serotonin reuptake inhibitor (ssri); Therapeutic: antidepressant; ssri Prototype: Fluoxetine HCl Pregnancy Category: C
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Availability
50 mg, 100 mg, 150 mg, 200 mg, 250 mg tablets
Action
Antidepressant with a dual mechanism of action. Inhibits neuronal serotonin (5-HT1) reuptake and also possesses 5-HT2 antagonist properties.
Therapeutic Effect
Antidepressant effects with minimal cardiovascular effects, fewer anticholinergic effects, less sedation, and less sexual
dysfunction than other antidepressants.
Uses
Treatment of depression.
Contraindications
Hypersensitivity to nefazodone or alcohol; hepatic disease, hepatitis, jaundice; MAOI therapy; mania; severe restlessness,
suicidal ideation; surgery, neonates; pregnancy (category C), lactation.
Cautious Use
Older adults, women of childbearing age; history of seizure disorders, seizures; renal or hepatic impairment; recent MI,
unstable cardiac disease; hypotension; angina, stroke, hypovolemia, dehydration, bipolar disorder; history of mania; ECT
therapy. Safety and efficacy in children <18 y are not established.
Route & Dosage
Depression Adult: PO 50100 mg b.i.d., may need to increase up to 300600 mg/d in 23 divided doses Geriatric: PO Start with 50 mg b.i.d.
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Administration
Oral
- Do not give within 14 d of discontinuation of an MAO inhibitor.
- Store at 15°30° C (59°86° F).
Adverse Effects (≥1%)
Body as a Whole: Anaphylactic reactions, angioedema.
CNS: Headache, dizziness, drowsiness, asthenia, tremor,
insomnia, agitation, anxiety.
GI: Dry mouth,
constipation, nausea, liver toxicity.
Special Senses: Visual disturbances, blurred vision, scotomata.
Endocrine: Galactorrheas, gynecomastia,
serotonin syndrome.
Skin: Stevens-Johnson syndrome, liver failure.
Interactions
Drug: May cause
serotonin syndrome (see Appendix F) with
maois or
ssris; may increase plasma levels of some
benzodiazepines, including
alprazolam and
triazolam. May decrease plasma levels and effects of
propranolol. May increase levels and toxicity of
buspirone, carbamazepine, cilostazol, digoxin; reports of QTc prolongation and ventricular arrhythmias with
pimozide; increased risk of rhabdomyolysis with
lovastatin, simvastatin; increased risk of
ergotamine toxicity with
dihydroergotamine, ergotamine. Herbal: St. John's wort may cause
serotonin syndrome.
Pharmacokinetics
Onset: 1 wk.
Peak: 35 wk.
Metabolism: In liver to at least two active metabolites.
Half-Life: Nefazodone 3.5 h, metabolites 233 h.
Nursing Implications
Assessment & Drug Effects
- Monitor for worsening of depression or emergence of suicidal ideation.
- Evaluate concurrent drugs for possible interactions.
- Monitor patients with a history of seizures for increased activity.
- Assess safety, as dizziness and drowsiness are common adverse effects.
- Lab tests: Monitor periodically liver function and CBC during long-term therapy.
Patient & Family Education
- Be aware that significant improvement in mood may not occur for several weeks following initiation of therapy.
- Do not drive or engage in potentially hazardous activities until response to the drug is known.
- Report changes in visual acuity.