Fluvoxamine (Luvox)

What fluvoxamine is

Fluvoxamine is a medication sold under the brand name Luvox. It works mainly on serotonin, one of the chemical messengers nerve cells use to communicate, and medicines that work this way are often called SSRIs (selective serotonin reuptake inhibitors). It is most often used for obsessive-compulsive disorder.

What it treats

Your clinician might suggest fluvoxamine for one of these, among other possible off-label uses:

• Obsessive-compulsive disorder
• Social anxiety, the intense fear of being judged in social situations

It is also used at times for depression and other situations. Whether it is a good fit depends on several factors, including your history and what you are working on. As with everything in psychiatry, that is decided case by case.

Who should not take fluvoxamine. FDA labeling lists a few firm exclusions. Fluvoxamine is not taken together with, or within 14 days of, a group of medicines called MAOIs, because the combination can cause a dangerous reaction called serotonin syndrome; that group includes the antibiotic linezolid and methylene blue given into a vein. It is not taken with tizanidine, thioridazine, alosetron, or pimozide. Make sure your clinician has your full medication list, including anything started recently or stopped within the last two weeks.

How it works

Honestly, no one knows with complete certainty how fluvoxamine produces its benefit. What research suggests is that it helps keep more serotonin available in the spaces between nerve cells, and that this serotonin effect is central to how it helps. The biology is only part of the picture: how much a medication helps, and how it feels, is individual. Two people on the same medication can have very different experiences.

How to take it

There is no single right way to take fluvoxamine; it depends on you and your clinician. Some people start low and increase slowly, others do not, and the timing and the form (immediate-release tablet or extended-release capsule) vary. The plan you and your clinician make together is the one to follow, not a number you read online. A few general points apply broadly:

• Take it the way you and your clinician agreed. It can be taken with or without food.
• Fluvoxamine can interact with a fair number of other medicines. Some combinations are best avoided, and others just need a closer eye. Even caffeine and tobacco can affect it. None of this means fluvoxamine is a difficult medicine to take; it is the reason your clinician wants a complete list of what you take, including over-the-counter and herbal products, and wants to know if your smoking or caffeine habits change.
• If you miss a dose, ask your clinician or pharmacist what to do rather than doubling up.
• Try not to stop on your own. Stopping suddenly can cause uncomfortable effects, and your clinician can taper it gently if and when that makes sense.

What to expect

This varies from person to person. Some effects can show up before the benefit does: possible side effects, if they happen, often appear in the first days, while any easing of obsessive thoughts, compulsions, or anxiety usually takes longer, commonly a few weeks and sometimes more. That early stretch is common and tends to ease. If nothing has shifted after a fair trial, that is useful information, not a dead end, and there are other options. As always, this is case by case.

Side effects

Not everyone gets side effects, and many that do happen ease over the first weeks. The lists below are possibilities, not certainties.

Possible more common side effects:

• Nausea, vomiting, loose stools, or indigestion, especially early on
• Trouble sleeping, or feeling drowsy or tired
• Feeling nervous or anxious, especially early on
• Headache or dizziness
• Less appetite, or a change in how things taste
• Sweating more than usual, or changes in sex drive or sexual function

If any of these stick around or bother you, they are worth raising. Send a non-urgent message through the patient portal or bring it up at your next visit; often a small change helps. Restlessness or anxiety that is new, worsening, or severe is a reason to contact your clinician promptly rather than wait.

Less common, but concerning side effects that could require emergency care:

• Signs of an allergic reaction. Call 911 right away for swelling of the face, lips, tongue, or throat, or trouble breathing. Contact your clinician promptly about a new rash or hives.
• Serotonin syndrome: agitation, confusion, a racing heart, fever, heavy sweating, or stiff or twitching muscles, sometimes after another medication is added
• Unusual bleeding or bruising
• A seizure
• Feeling abnormally high, wired, or irritable, with racing thoughts and far less need for sleep than usual
• Eye pain or redness, or changes in vision such as blurred sight or seeing rings around lights
• Headache with weakness, confusion, trouble concentrating or remembering, or feeling unsteady
• Any new or worsening thoughts of harming yourself, whether or not you think the medication is behind it

For any of these, use the help options at the top of this page: call 911 or go to the nearest emergency department for a medical emergency or severe reaction, or call or text 988 for a mental health crisis.

If serotonin syndrome or a seizure is the concern, tell the clinicians treating you everything you take, including this medication. They may decide to stop it.

Pregnancy and breastfeeding

If you are pregnant, thinking about it, or breastfeeding, this is worth going through together rather than settling from a page. What follows is what the research currently shows. Tell your clinician before changing anything, and do not stop suddenly on your own.

In pregnancy

FDA labeling says that long experience with fluvoxamine in pregnancy, from published observational studies over decades, has not identified a clear risk of major birth defects or miscarriage from the medication. For scale, labeling puts the background chance of a major birth defect at 2 to 4 in 100 pregnancies, before any particular exposure is considered.

Two findings about SSRIs as a group apply here:

• A newborn lung condition. Some studies suggest that SSRIs taken in the second half of pregnancy might raise the chance of persistent pulmonary hypertension of the newborn, and others have not found this. It occurs in about 1 or 2 of every 1,000 births to begin with, and if SSRIs do raise it, the overall chance stays under 1 in 100.
• Bleeding after delivery. FDA labeling notes that SSRI use, particularly in the month before delivery, has been associated with a higher chance of postpartum hemorrhage. Worth making sure whoever delivers your baby knows what you are taking, well before the day.

Symptoms in the newborn. FDA labeling reports that babies exposed to SSRIs late in pregnancy can have symptoms that start right after delivery. They can include irritability, jitteriness, trembling, constant crying, stiff or floppy muscle tone, a bluish tinge to the skin, trouble feeding, vomiting, low blood sugar, trouble holding a steady temperature, trouble breathing, and seizures, and some newborns have needed a longer hospital stay, help with breathing, or tube feeding. The useful thing you can do is make sure the delivery team knows about the medication ahead of time, so someone is watching for it.

While breastfeeding

Fluvoxamine passes into breast milk. LactMed, the National Institutes of Health lactation database, describes the information as limited. It reports that, at the doses that have been studied, the levels in milk are low and would not be expected to cause side effects in a breastfed baby, especially one older than 2 months, and that needing fluvoxamine is not a reason to stop breastfeeding. Most babies tested have had no measurable fluvoxamine in their blood, though one had a raised level. The limited long-term follow-up has not shown effects on growth or development.

FDA labeling says most reported cases involved no side effects in the baby, and notes reports of diarrhea, vomiting, less sleep, and agitation. If you notice any of these, call the pediatrician.

Separately, some people taking an SSRI have a harder time getting breastfeeding established, and it is not clear how much of that is the medication and how much is the condition being treated. It is a good reason to line up lactation support early rather than to assume it will not work.

If you are a man taking fluvoxamine

Fluvoxamine can cause sexual side effects. FDA labeling says animal findings suggest fertility may be affected while taking it. Human studies of a father's use were not found in the sources used for this page.

Registries

There is a national registry that follows pregnancy outcomes for people taking psychiatric medications, and you can enroll yourself rather than waiting to be asked. It is listed in the references at the bottom of this page.

When to reach out, and where

For routine questions, side effects that can wait, or how things are going, send your clinician a message through the patient portal. These are part of your ongoing care and are answered in the normal course of a few business days, so they are best for things that are not urgent.

If something feels urgent, you do not need to wait for a reply. The help options at the top of this page are the fastest way to get care: 911 or the nearest emergency department for a medical emergency or severe reaction, or 988 any time for a mental health crisis or thoughts of self-harm.

Questions to ask your clinician

• What are you hoping fluvoxamine will help with in my case?
• How and when will we know if it is working?
• Could it interact with my other medications, or with caffeine or tobacco?
• What should I do if I notice side effects?
• How long should I give it before we reassess?
• How will we handle stopping it, if and when we get there?