An SSRI antidepressant
Fluvoxamine
An SSRI antidepressant used for depression and obsessive-compulsive disorder, notable for some strong drug interactions.
What is Fluvoxamine?
Fluvoxamine is a selective serotonin reuptake inhibitor (SSRI) antidepressant used for depression and obsessive-compulsive disorder. It increases serotonin activity in the brain to help lift mood, takes a few weeks to work, and should not be stopped abruptly. It has some important drug interactions, including with theophylline, clozapine and caffeine.
Education and reference only. This is a plain-language guide to Fluvoxamine — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Fluvoxamine is one of the SSRI antidepressants, a widely used class for depression and anxiety-related conditions. In the UK it is used for depression and for obsessive-compulsive disorder (OCD). A particular feature of fluvoxamine is that it strongly inhibits certain liver enzymes, so it has more drug interactions than some other SSRIs. Like all antidepressants it takes a few weeks to work and is taken regularly rather than as needed.
How it works
Fluvoxamine increases the amount of the brain chemical serotonin available between nerve cells by blocking its reuptake. Over a few weeks this is thought to help improve mood and reduce the obsessive thoughts and compulsions of OCD. It also blocks certain liver enzymes that break down other medicines, which is why it can raise the levels of drugs such as theophylline, clozapine and caffeine.
What it treats
Conditions Fluvoxamine is used for
Practical use
How to take Fluvoxamine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it regularly each day as prescribed, with or without food.
- Taking it with food can help if it causes nausea, which is common early on.
- Keep taking it even if you feel no better at first; the benefit builds over a few weeks.
- Do not stop abruptly — coming off it is done gradually to reduce discontinuation symptoms.
- Be mindful of caffeine, as fluvoxamine can increase its effects and cause jitteriness.
- If you miss a dose, take it when you remember unless it is nearly time for the next one — do not double up.
Weighing it up
Advantages & disadvantages of Fluvoxamine
Advantages
- An effective treatment for both depression and obsessive-compulsive disorder.
- Does not cause the physical dependence seen with some other types of medicine.
- A long-established SSRI with a well-understood profile.
- Available as tablets, making it straightforward to take.
Disadvantages
- Has more drug interactions than some other SSRIs because it strongly inhibits liver enzymes.
- Nausea is common in the first week or two.
- Takes a few weeks to work, so patience is needed.
- Must not be stopped abruptly because of discontinuation symptoms.
Practical use
Good to know
It takes a few weeks before the benefit is felt, and nausea is common in the first week or two but usually settles. It must not be stopped abruptly, as this can cause discontinuation symptoms such as dizziness and flu-like feelings; coming off it is done gradually. Because it strongly affects certain liver enzymes, always tell your pharmacist or prescriber what else you take — including caffeine intake — so interactions can be checked.
Who should not take it / use with caution
- People taking MAOI antidepressants, or within a required gap after stopping one.
- Used with caution alongside medicines such as theophylline, clozapine and tizanidine because of strong interactions.
- Used with caution in epilepsy, bleeding disorders, liver problems and in people with a history of mania.
- Caution in pregnancy and breastfeeding — discussed with the prescriber.
Monitoring
- Review of mood, response and any thoughts of self-harm, particularly in the early weeks.
- A check for signs of serotonin syndrome when combined with other serotonin-raising medicines.
- Sodium levels may be checked, particularly in older people.
Side effects
- Nausea, especially in the first week or two.
- Headache, drowsiness or difficulty sleeping.
- Dry mouth, sweating and reduced appetite.
- Sexual difficulties such as reduced desire or delayed orgasm.
- Rarely, low sodium levels, an increased tendency to bleed, or serotonin syndrome (agitation, sweating, tremor and a fast heartbeat).
Key interactions
- Strongly raises levels of theophylline, clozapine, tizanidine and caffeine — these need care or avoidance.
- Must not be combined with MAOI antidepressants; a gap is needed when switching.
- Other medicines that raise serotonin increase the risk of serotonin syndrome.
- Anti-inflammatory painkillers, aspirin and anticoagulants increase the risk of bleeding.
Available as: Tablets.
Answers
Fluvoxamine: frequently asked questions
How long does fluvoxamine take to work?
It usually takes a few weeks of regular use before you notice the full benefit, so keep taking it even if you feel no change at first.
Why does it interact with so many medicines?
Fluvoxamine strongly blocks certain liver enzymes, so it can raise the levels of other medicines such as theophylline and clozapine. Always have new medicines checked.
Can I stop taking it suddenly?
No. Stopping abruptly can cause discontinuation symptoms such as dizziness and flu-like feelings. The dose is reduced gradually under medical advice.
Does fluvoxamine affect caffeine?
Yes, it can increase the effects of caffeine and make you feel jittery or restless, so it helps to be mindful of how much you drink.
Is the early nausea a problem?
Nausea is common in the first week or two and usually settles. Taking it with food can help; tell your prescriber if it does not improve.
The wider class
About SSRIs
Fluvoxamine belongs to the ssris class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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