Fluvoxamine (Luvox, Faverin, Dumyrox, Dumirox, Favoxil, Floxyfral, Maveral)

Fluvoxamine was one of the first SSRI antidepressants on the market; it was introduced in Switzerland in 1984 by Solvay Pharmaceuticals. Fluvoxamine has a different chemical structure than other SSRIs and therefore has a slightly different pharmacological profile. Solvay's patent expired in 2000, allowing the distribution of generic fluvoxamine.

In 2002, Solvay petitioned the FDA to withdraw approval of Luvox while the company reexamined chemical and manufacturing data. At the same time, Solvay stopped shipping Luvox to the US. They continued to distribute it in all other markets.

Jazz Pharmaceuticals has recently purchased a license to distribute Luvox and Luvox CR (sustained release) in the US. They anticipate receiving FDA approval soon and plan to begin distribution early in 2008.

The Bottom Line: What You Really Need to Know

Uses of fluvoxamine

Fluvoxamine is used primarily for the treatment of obsessive compulsive disorder (OCD) in adults and children. It is also approved to treat depression, panic disorder, social anxiety disorder and post-traumatic stress disorder. In adults it is also used for irritable bowel syndrome, obesity, bulimia, generalized anxiety disorder (GAD) schizophrenia, and chronic tension headaches. It is prescribed for children who have social anxiety disorder (SAD) and separation anxiety disorder.

Jazz Pharmaceuticals has requested approval to market Luvox for the treatment of OCD and SAD.

Dosage and instructions

The usual dose of fluvoxamine for adults is 100-200 mg/day for depression and 150-300 mg/day for OCD. The dosage range for children is 25-200 mg/day.

Adults usually begin taking 50 mg/day of fluvoxamine and the dose is increased in 50 mg/day increments every few days as needed until the best daily dose is established.

Fluvoxamine has a shorter half-life than most SSRIs-only 17-22 hours after a steady dose has been established. "Half life" is the amount of time it takes for your body to excrete half of the dose; when half of the dose has been excreted, levels of the drug in your blood and tissues begin to drop. For that reason, when large doses of fluvoxamine are used-over 150 mg/day-the dose is divided and taken twice a day, in the morning and evening.

Children, elderly people and people with liver or kidney problems need smaller doses of fluvoxamine. They begin with 25 mg/day and the dose is increased in 25 mg/day increments.

How fluvoxamine works

Like other SSRIs, fluvoxamine works by preventing the reabsorption of serotonin at nerve cell endings. This allows serotonin to accumulate; serotonin depletion is thought to cause depression, obsessions and other psychological conditions.

Fluvoxamine is metabolized (broken down) by the liver and excreted in urine.

Side effects

The most common side effects of fluvoxamine are decreased libido, decreased sexual functioning, drowsiness and fatigue, gastrointestinal problems, dizziness, headache, nervousness, sleeping problems, sweating and tremors. These side effects usually get better after you have been taking the medication for a while.

Allergic reactions can occur and can be mild (rashes or hives) or severe and life-threatening (anaphylaxis and shock).

Sexual side effects frequently occur with SSRI antidepressants like fluvoxamine. Decreased libido, inability to experience orgasm and ejaculation problems may occur.

Other side effects that people have experienced while taking fluvoxamine are:

Serious side effects are discussed in the section on Warnings and Precautions, and include:

Drug interactions

Like other SSRI medications, fluvoxamine must not be taken at the same time as a MAOI antidepressant (Marplan, Manerix, Emsam, Nardil, Parnate) because they can cause a serious interaction. You should allow at least two weeks after you stop taking one type of medication (SSRI or MAOI) before you begin taking the other.

Terfenadine (Seldane), thoridazine (Mellaril), Mesoridazine (Serentil), Cisapride (Propulsid), pimoxide (Orap) and astemizole (Hismanol) all interact with fluvoxamine in a way that can cause life-threatening heart rhythms and they should not be taken at the same time. Don't take thoridazine for at least 5 weeks after you stop taking fluvoxamine.

Many other drugs can interact with fluvoxamine. The most common ones are:

Withdrawal from fluvoxamine

SSRIs cannot be discontinued abruptly; they must be tapered gradually. If you don't taper the medication you can experience dizziness, nausea and vomiting, "electric shock" feelings, muscle twitches and other symptoms.

Warnings, precautions and contraindications

Increased suicidality: SSRI medications may cause an increased risk of suicide, especially during the first few weeks of treatment. Anyone who starts taking fluvoxamine should be monitored closely for the first month or more. You should have weekly face-to-face appointments with a physician or therapist and daily interactions with family or friends. Family members and friends should be instructed to check on you at least daily and to ask if you have thoughts of harming or killing yourself. The physician should be notified immediately if any of the following occur:

Serotonin syndrome: Serotonin syndrome is a type of serotonin toxicity. It is most likely to occur when an SSRI like fluvoxamine is taken at the same time as another medication that has an effect on serotonin. Symptoms affect the central nervous, cardiovascular, musculoskeletal and autonomic nervous systems and range from mild to severe.

The symptoms of serotonin syndrome begin abruptly, usually within a few hours after taking a medication. They can progress rapidly and lead to multiple organ failure, cardiovascular collapse and death.

Mania: Sometimes antidepressants can cause mania, especially in people who are bipolar. The mania can become very severe and can lead to paranoia, delirium and psychosis. There have been instances of violent behavior in people who are taking fluvoxamine and other SSRI's and some people believe these episodes were caused by the medication. Mania is most likely to happen in the first few weeks of treatment. Restlessness, anxiety, agitation and unusual thought patterns may precede manic episodes and should be reported to a physician immediately.

Use in pregnancy: SSRIs, including fluvoxamine, may cause cardiac birth defects when the mother takes them during the first trimester of pregnancy. When they are taken during the last trimester, they may cause a serious heart and lung problem called persistent pulmonary hypertension of the newborn (PPHN). These medications are not recommended for women who are or would like to become pregnant.

Fluvoxamine is found in breast milk and should be used with caution in mothers who are breast-feeding.

Controversy

Although fluvoxamine is usually used for OCD, it is also approved for depression. People who were taking fluvoxamine (as well as other SSRIs) have committed acts of violence, and some people believe there is a causal link. This issue received national attention when it was discovered that Eric Harris, one of the Columbine school shooters, was taking Luvox for depression.

After Columbine, it was discovered that, when Luvox was being evaluated, one person who was taking it committed murder. Solvay Pharmaceuticals was accused of suppressing that information.

Other SSRI medications have been implicated in other incidents of violence. The horror of the Columbine massacre and Solvay's apparent suppression of data made people suspicious of the safety of Luvox, and the drug rapidly lost favor and market share. Solvay voluntarily withdrew Luvox from the US market, even though neither Solvay nor the FDA had concerns about the safety of the drug. Luvox will probably be reintroduced to the US market sometime in early 2008.

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