Overview
DESCRIPTION Nefazodone hydrochloride tablets, USP are an antidepressant for oral administration with a chemical structure unrelated to selective serotonin reuptake inhibitors, tricyclics, tetracyclics, or monoamine oxidase inhibitors (MAOI). Nefazodone hydrochloride is a synthetically derived phenylpiperazine antidepressant.
Mechanism of Action
CLINICAL PHARMACOLOGY Pharmacodynamics The mechanism of action of nefazodone, as with other antidepressants, is unknown. Preclinical studies have shown that nefazodone inhibits neuronal uptake of serotonin and norepinephrine. Nefazodone occupies central 5-HT 2 receptors at nanomolar concentrations, and acts as an antagonist at this receptor. Nefazodone was shown to antagonize alpha 1 -adrenergic receptors, a property which may be associated with postural hypotension. In vitro binding studies showed that nefazodone had no significant affinity for the following receptors: alpha 2 and beta adrenergic, 5-HT 1A , cholinergic, dopaminergic, or benzodiazepine.
Indications
- INDICATIONS AND USAGE Nefazodone hydrochloride tablets are indicated for the treatment of depression. When deciding among the alternative treatments available for this condition, the prescriber should consider the risk of hepatic failure associated with nefazodone hydrochloride treatment (see WARNINGS ). In many cases, this would lead to the conclusion that other drugs should be tried first. The efficacy of nefazodone in the treatment of depression was established in 6 to 8 week controlled trials of outpatients and in a 6 week controlled trial of depressed inpatients whose diagnoses...
Common Doses
- 200 mg
- 600 mg
- 100 mg
- 438 mg
Dosage
DOSAGE AND ADMINISTRATION When deciding among the alternative treatments available for depression, the prescriber should consider the risk of hepatic failure associated with nefazodone hydrochloride treatment (see WARNINGS ). Initial Treatment The recommended starting dose for nefazodone hydrochloride tablets USP is 200 mg/day, administered in two divided doses (BID). In the controlled clinical trials establishing the antidepressant efficacy of nefazodone, the effective dose range was generally 300 to 600 mg/day.
Black Box Warning
Suicidality and Antidepressant Drugs Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of nefazodone hydrochloride tablets or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need.
Contraindications
- CONTRAINDICATIONS Coadministration of terfenadine, astemizole, cisapride, pimozide, or carbamazepine with nefazodone hydrochloride is contraindicated (see WARNINGS and PRECAUTIONS ). Nefazodone hydrochloride tablets are contraindicated in patients who were withdrawn from nefazodone because of evidence of liver injury (see BOXED WARNING ). Nefazodone hydrochloride tablets are also contraindicated in patients who have demonstrated hypersensitivity to nefazodone hydrochloride, its inactive ingredients, or other phenylpiperazine antidepressants.
Side Effects
- ADVERSE REACTIONS Associated with Discontinuation of Treatment Approximately 16% of the 3496 patients who received nefazodone in worldwide premarketing clinical trials discontinued treatment due to an adverse experience. The more common (≥ 1%) events in clinical trials associated with discontinuation and considered to be drug related (i.e., those events associated with dropout at a rate approximately twice or greater for nefazodone compared to placebo) included: nausea (3.5%), dizziness (1.9%), insomnia (1.5%), asthenia (1.3%), and agitation (1.2%).
Interactions
- Drug Interactions Drugs Highly Bound to Plasma Protein Because nefazodone is highly bound to plasma protein (see CLINICAL PHARMACOLOGY , Pharmacokinetics ), administration of nefazodone to a patient taking another drug that is highly protein bound may cause increased free concentrations of the other drug, potentially resulting in adverse events. Conversely, adverse effects could result from displacement of nefazodone by other highly bound drugs.