Nefazodone (Serzone)
Nefazodone is a newer antidepressant that has a different structure and means of action than most others. It is not a monamine oxidase inhibitor (MAOI), a tricyclic antidepressant (TCA) or a serotonin selective uptake inhibitor (SSRI). Bristol-Meyers-Squibb received FDA approval to market Serzone for the treatment of depression in 1994.
During post-approval use, it became apparent that liver damage and failure is a rare side effect of nefazodone and it can require liver transplant or can result in death. Because there is no way to determine who will or will not have liver damage when taking the medication, nefazodone was banned in Canada, Europe and some other places in 2002-2003.
Nefazodone is still available in the USA as a generic medication. Bristol-Meyers-Squibb stopped manufacturing and selling Serzone in 2004 because of declining sales.
The Bottom Line: What You Really Need to Know
- Nefazodone (Trade Names: Serzone) is used to treat depression.
- The usual starting dose is 100 mg twice a day. The dose can be slowly increased to as much as 600 mg/day total dose.
- Nefazodone interacts with many medications. Make sure your doctor and pharmacist know about all of the medications you take, including over-the-counter medications, herbal remedies, homeopathic remedies, vitamins, supplements and medications you only take occasionally.
- It will probably be a week or two before you notice any difference in the way you feel.
- Don't stop taking nefazodone suddenly; the dose must be tapered gradually or you may experience withdrawal symptoms.
- Most people have a few mild side effects, like dry mouth, sleepiness or nausea, when they start taking nefazodone. They usually go away with time.
- If you experience dizziness, light-headedness or fainting when you stand up suddenly, move to a standing position more slowly. Sit up for a few moments before standing.
- Nefazodone can make you more sensitive to UV rays. Be sure to use sun screen and protective clothing when you are exposed to sun. Avoid tanning.
- If you experience loss of interest in sex or diminished sexual ability or an erection lasting longer than 4 hours, talk to your doctor about it.
- Nefazodone can cause liver damage; your doctor may want to draw blood to check your liver function periodically.
- Have a friend or family member check in with you every day for the first few weeks you take nefazodone. Ask him or her to help monitor your condition for
- Worsening depression
- Restlessness, irritability, agitation, hostility or aggression
- Unusual thoughts or thoughts of suicide
- Report any serious or unusual side effects to your doctor.
- People who have had a heart attack or stroke in the past several months should not take nefazodone.
Uses
Nefazodone is used to treat depression.
Dosage and instructions
Most people begin taking nefazodone with 100 mg twice a day. The dose is slowly increased as tolerated to a maximum of 600 mg/day.
How nefazodone works
Depression is thought to be at least partially due to abnormalities in the chemicals that are found between nerve cells. These chemicals are always present, and they are always being excreted and absorbed by the nerve cells. Nefazodone seems to increase serotonin levels by preventing uptake and reuptake, and to inhibit norepinephrine reuptake.
Side Effects
Some of the side effects that nefazodone produces are:
- Dry mouth
- Sleepiness
- Nausea, upset stomach, constipation
- Dizziness
- Visual problems
- Confusion
- Feeling lightheaded or fainting when you first stand up
- Sensitivity to the sun or UV rays
- Changes in appetite or weight
- Problems with urination
- Sweating
- Tremors and restlessness
- Decrease in libido or sexual functioning-less common with nefazodone than other antidepressants
- Priapism-erection lasting more than 4 hours
Interactions
MAOI antidepressants: If nefazodone and MAOI antidepressants are taken concurrently, a serious and severe interaction can result. The symptoms can include extremely high fever, muscle rigidity, convulsions, coma and death. MAOI antidepressants should be stopped at least two weeks before starting nefazodone. Nefazodone has a relatively short half-life (a measure that indicates how long the drug is effective) so MAOI's can be started a week after stopping it.
Terfenedine (Seldane) and astemizole (Hismanol): These medications must not be taken with nefazodone. The interaction between them can cause fatal heart dysrhythmias.
Triazolam (Halcion) and alprazolam (Xanax): These medications must be taken in very low doses, if at all, when you are taking nefazodone.
Other medications that interact with nefazodone and should be avoided are:
- Carbamezepine (Tegretol)
- Pimozide (Orap)
- Cisapride (Propulsid)
Withdrawal
Although no one knows if discontinuation symptoms will occur when nefazodone is abruptly withdrawn, we assume that they will. Most other antidepressants require gradual withdrawal, so nefazodone probably does, too.
Precautions, warnings and contraindications
Suicide risk: There is an increased risk of suicide with all antidepressants, especially when you first start taking them. Close monitoring and frequent follow-up is important. Be sure to report any unusual thoughts, feelings or behaviors to your physician.
Liver damage: Liver damage, sometimes requiring liver transplant and sometimes ending in death, has occurred rarely in patients who are taking nefazodone. There is no way to predict who will have liver damage when taking nefazodone; signs and symptoms can appear after two weeks of treatment or not for six months of more. Your doctor will draw blood at frequent intervals to evaluate your liver function.
MAOIs: Nefazodone should not be taken less than two weeks after discontinuing monamine oxidase inhibiting antidepressants.
Seizures: Nefazodone lowers the seizure threshold; people who are susceptible to seizures may experience them after starting this medication.
Mania and psychosis: People with bipolar disorder can experience manic episodes while taking nefazodone unless they are also taking a mood stabilizer. People who are schizophrenic may experience psychotic episodes while taking nefazodone.
Nefazodone should not be taken if you have recently had a heart attack or stroke.
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