Nefazodone Full Prescribing Information

Brand Name: Serzone
Generic Name: Nefazodone

Serzone (Nefazodone) is an antidepressant used to treat mental depression. Usage, dosage, side effects of Serzone.


Indications and Usage
Drug Interactions
Adverse Reactions

Ed. Note: Sale of Serzone was discontinued in 2003 in some countries (U.S., Canada and others), due to the small possibility of hepatic (liver) injury, which could lead to the need for a liver transplant, or even death. Several generic formulations of nefazodone are still available.

Serzone patient information (in plain English)


Nefazodone is an antidepressant used to treat mental depression.



Nefazodone HCl is 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. 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.

Peak plasma concentrations occur at about one hour.


Indications and Usage


Nefazodone (Serzone) is indicated for the treatment of depression.

The effectiveness of nefazodone in long-term use (i.e., for more than 6 to 8 weeks) has not been systemically evaluated in controlled trials. Therefore, the physician who elects to use nefazodone for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient.


Coadministration with terfenadine or astemizole with nefazodone HCl is contraindicated.

Nefazodone is contraindicated in patients with known hypersensitivity to nefazodone or other phenylpiperazine antidepressants.


MAO Inhibitors: Nefazodone should not be used in combination with MAO inhibitors or within 2 weeks of terminating treatment with MAO inhibitors. MAO inhibitors should not be introduced until at least 2 weeks after the cessation of nefazodone therapy.

Nefazodone has been reported to increase the plasma levels of certain triazolobenzodiazepines (e.g., triazolam and alprazolam) resulting in an enhancement of the psychomotor impairment caused by these agents.

Increased plasma concentrations of terfenadine and astemizole are associated with QT prolongation and with rare cases of serious cardiovascular events, including death, due principally to ventricular tachycardia. Consequently, it is recommended that nefazodone not be used in combination with either terfenadine or astemizole.



Suicide: The possibility of a suicide attempt is inherent in depression and may persist until significant remission occurs. Close supervision of high risk patients should accompany initial drug therapy. Prescriptions for nefazodone should be written for the smallest quantity of tablets consistent with good patients management in order to reduce the risk of overdose.

Cardiovascular: Nefazodone should be used with caution in patients with known cardiovascular or cerebrovascular disease that could be exacerbated by hypotension (history of myocardial infarction, angina, or ischemic stroke) and conditions that would predispose the patients to hypotension (dehydration, hypovolemia, and treatment with antihypertensive medication).

Activation of Mania/Hypomania: Activation of mania/hypomania is a known risk in a small proportion of patients with major affective disorder treated with other marketed antidepressants. As with all antidepressants, nefazodone HCl should be used cautiously in patients with a history of mania.

Seizures: During premarketing testing, a recurrence of petit mal seizure was observed in a patient receiving nefazodone who had a history of such seizures. One nonstudy participant took 2000-3000 mg of nefazodone with methocarbamol and alcohol; this person reportedly experienced a convulsion. This drug should be discontinued in any patient who develops seizures.

Priapism: While priapism did not occur during premarketing experience with nefazodone, priapism has been reported with a structurally related drug, trazodone. If patients present with prolonged or inappropriate erections, they should discontinue therapy immediately and consult their physicians. If the condition persists for more than 24 hours, a urologist should be consulted to determine appropriate treatment.

Allergic Reactions: Patients should be advised to notify their physician if they develop a rash, hives, or a related allergic phenomenon.

Usage in Children:: The drug is not recommended for use in children.

Pregnancy and Withdrawl: Safe use of Nefazodone during pregnancy or lactation has not been established; therefore, its use in pregnancy, in nursing mothers or in women of childbearing potential requires that the benefits of treatment be weighed against the possible risks to mother and child.

Interference with Cognitive or Motor Performance: Since any psychoactive drug may impair judgement, thinking, or motor skills, patients should be cautioned about operating hazardous machinery, including automobiles, until they are reasonably certain that nefazodone therapy does not adversely affect their ability to engage in such activities.

Prior to elective surgery: Little is known about the interaction between Nefazodone and general anesthetics. Nefazodone should be discontinued for as long as clinically feasible.


Drug Interactions

Monoamine Oxidase Inhibitors: In patients receiving antidepressants with pharmacological properties similar to nefazodone in combination with a monoamine oxidase inhibitor (MAOI), there have been reports of serious, sometimes fatal, reactions. For a selective serotonin reuptake inhibitor, these reactions have included hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, and mental status changes that include extreme agitation progressing to delirium and coma. These reactions have also been reported in patients who have recently discontinued the drug and have been started on a MAOI. Some cases presented with features resembling neuroleptic malignant syndrome. Severe hyperthermia and seizures, sometimes fatal, have been reported in association with the combined use of tricyclic antidepressants and MAOIs. These reactions have also been reported in patients who have recently discontinued these drugs and have been started on an MAOI.

Concomitant Medication: Patients should be advised to inform their physicians if they are taking, or plan to take, any prescription or over-the-counter drugs, since there is a potential for interactions. Significant caution is indicated if nefazodone (Serzone) is to be used in combination with either Halcion or Xanax, and concomitant use with Seldane or Hismanal is contraindicated.

Alcohol: Patients should be advised to avoid alcohol while taking nefazodone.

Haloperidol: Dosage adjustment of haloperidol may be necessary when coadministered with nefazodone.

Coadministration of nefazodone potentiated the effects of triazolam on psychomotor performance tests. If triazolam is coadministered with nefazodone, a 75% reduction in the initial triazolam dosage is recommended. For many patients, e.g., the elderly, it is recommended that triazolam not be used in combination with nefazodone.

Triazolam: The concomitant use of nefazodone and triazolam should be avoided.

Alprazolam: If alprazolam is coadministered with nefazodone, a 50% reduction in the initial alprazolam dosage is recommended. No dosage adjustment is required for nefazodone.

Other CNS Active Drugs: The use of nefazodone in combination with other CNS-active drugs has not been systematically evaluated. Consequently, caution is advised if concomitant administration of nefazodone and such drugs is required.

BEFORE USING THIS MEDICINE: INFORM YOUR DOCTOR OR PHARMACIST of all prescription and over-the-counter medicine that you are taking. This includes cisapride, astemizole, terfenadine, and medicines for depression. Inform your doctor of any other medical conditions, allergies, pregnancy, or breast-feeding. Inform your doctor of any other medical conditions including heart/circulation, liver, or kidney problems, epilepsy, allergies, pregnancy, or breast-feeding.


Adverse Reactions

Side Effects That Should Be Reported To Your Doctor: Agitation; blurred vision or other changes in vision; confusion; dizziness or lightheadedness, clumsiness or unsteadiness; difficult or frequent urination; difficulty concentrating; memory problems; skin rash or itching.

Side effects, that may go away during treatment, include headache, dry mouth, nausea, drowsiness, dizziness, weakness, constipation, lightheadedness, increased appetite, ringing in ears, strange dreams. If they continue or are bothersome, check with your doctor. CHECK WITH YOUR DOCTOR AS SOON AS POSSIBLE if you experience blurred vision.

Drug Abuse and Dependence

Nefazodone is not a controlled substance. Nefazodone showed no potential for abuse in a controlled study of abuse liability. Nefazodone has not been systematically studied in humans for its potential for tolerance, physical dependence or withdrawal.

While the premarketing clinical experience with nefazodone did not reveal any tendency for a withdrawal syndrome or any drug-seeking behavior, these observations were not systematic, and it is not possible to predict on the basis of this limited experience the extent to which a CNS-active drug will be misused, diverted, and/or abused once marketed. Consequently, physicians should carefully evaluate patients for a history of drug abuse and follow such patients closely, observing them for signs of misuse or abuse of nefazodone (e.g., development of tolerance, dose escalation, drug-seeking behavior).



Signs and Symptoms

Symptoms of overdose may include nausea, vomiting, sluggishness, and increased sweating.


If you or someone you know may have used more than the recommended dose of this medicine, contact your local poison control center or emergency room immediately.

There is no specific antidote for nefazodone. Treatment should be symptomatic and supportive in the case of hypotension or excessive sedation. Any patient suspected of having taken an overdose should have the stomach emptied by gastric lavage.

In managing overdosage, consider the possibility of multiple drug involvement.



As with all antidepressants, several weeks on treatment may be required to obtain the full antidepressant effect. Once improvement is noted, it is important for patients to continue drug treatment as directed by their physician.

Do not exceed the recommended dosage or take this medicine for longer than prescribed.

  • Follow the directions for using this medicine provided by your doctor.
  • Store this medicine at room temperature, in a tightly-closed container, away from heat and light.
  • If you miss a dose of this medicine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do NOT take 2 doses at once.

Additional Information:: Do not share this medicine with others for whom it was not prescribed. Do not use this medicine for other health conditions. Keep this medicine out of the reach of children.

The recommended starting dose for nefazodone HCl is 200 mg/day, administered in two divided doses (BID). In the controlled clinical trials establishing the anti-depressant efficacy of nefazodone HCl, the effective dose range was generally 300 to 600 mg/day. Consequently, most patients, depending on tolerability and the need for further clinical effect, should have dose increased. Dose increases should occur in increments of 100 mg/day to 200 mg/day, again on a BID schedule, at intervals of no less than 1 week.

Elderly and Debilitated Patients: The recommended dose for elderly or debilitated patients is 100 mg/day on a BID schedule. These patients often have reduced nefazodone clearance and/or increased sensitivity to the side effects of CNS-active drugs.

Maintenance/Continuation/Extended Treatment: There is no body of evidence available from controlled trials to indicate how long the depressed patients should be treated with nefazodone HCl. It is generally agreed, however, that pharmacological treatment for acute episodes of depression should continue for up to six months or longer.

IF USING THIS MEDICINE FOR AN EXTENDED PERIOD OF TIME, obtain refills before your supply runs out.


How Supplied


100 mg: Each white, hexagonal, flat-faced, beveled-edged tablet, engraved with "BMS 100" and a bisect score on one side and "32" and a bisect score on the other, contains: nefazodone HCl 100 mg. Nonmedicinal ingredients: colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose, povidone and sodium starch glycolate. Bottles of 60.

150 mg: Each peach, hexagonal, flat-faced, beveled-edged tablet, engraved with "BMS 150" and a bisect score on one side and "39" and a bisect score on the other, contains: nefazodone HCl 150 mg. Nonmedicinal ingredients: colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose. povidone, red ferric oxide, sodium starch glycolate and yellow ferric oxide. Bottles of 60.

200 mg: Each light yellow, hexagonal, flat-faced, beveled-edged tablet, engraved with "BMS 200" on one side and "33" on the other, contains: nefazodone HCl 200 mg. Nonmedicinal ingredients: colloidal silicon dioxide. magnesium stearate, microcrystalline cellulose, povidone, sodium starch glycolate and yellow ferric oxide. Bottles of 60.

IF USING THIS MEDICINE FOR AN EXTENDED PERIOD OF TIME, obtain refills before your supply runs out.

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Serzone Patient Information Sheet (in plain English)

The information in this monograph is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects. This information is generalized and is not intended as specific medical advice. If you have questions about the medicines you are taking or would like more information, check with your doctor, pharmacist, or nurse.

Copyright © 2007 Healthyplace Inc. All rights reserved.

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APA Reference
Writer, H. (2009, January 3). Nefazodone Full Prescribing Information, HealthyPlace. Retrieved on 2019, August 20 from

Last Updated: April 9, 2017

Medically reviewed by Harry Croft, MD

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