Other names: Prozac. Several non branded versions are also available.
Fluoxetine is one of the class of SSRI (selective serotonin reuptake inhibitor) drugs. It is normally prescribed for depression. Exploratory studies have also looked at whether fluoxetine might have a role in reducing inflammation around nerves in multiple sclerosis. Although some effect was recorded, larger studies are needed to test this idea.
Fluoxetine was one of three drugs being studied by the phase II MS-SMART trial, which involved 440 people with secondary progressive MS. Results didn't find fluoxetine to be effective at protecting nerves from damage. A separate clinical trial also failed to show a neuroprotective effect of fluoxetine in people with primary or secondary progressive MS.
How fluoxetine works
Fluoxetine works by increasing the stimulation between some cells in the brain.
How fluoxetine is given
Fluoxetine is taken orally, as tablets. Dosages vary and it is normally prescribed by a GP.
Fluoxetine is a long-term treatment. Individuals should allow four to six weeks to feel the benefit of fluoxetine.
Fluoxetine remains in the body for some weeks after an individual has stopped taking the drug, therefore, individuals should not stop abruptly but taper off treatment with a doctor's advice.
Dizziness or lightheadedness particularly on getting up from a lying or sitting position, dry mouth, decreased sexual drive or ability, diarrhoea, drowsiness, headache, trouble sleeping, abnormal dreams, fast or irregular heartbeat, frequent urination, menstrual pain, tiredness or weakness, tremor, vomiting. Most of these are transitory and will go away once someone has adjusted to the medication.
Fluoxetine can interfere with sleep, so is best taken in the morning. It can upset the stomach and may be taken with or after food.
Fluoxetine should not be taken by people with reduced liver function, acute heart conditions, diabetes, history of bleeding disorders, or a history of some types of mental health problems. It should also not be taken during pregnancy or when still breastfeeding.
- Canadian Journal of Psychiatry 1992;37(2):147-148. Summary The effect of fluoxetine in depression associated with multiple sclerosis.
- Journal of Neurology Neurosurgery and Psychiatry 2008;79(9):1027-1031. Summary Effects of fluoxetine on disease activity in relapsing multiple sclerosis: a double-blind, placebo-controlled, exploratory study.
- Multiple Sclerosis Journal 2019;25(13):1728–1735. Summary Fluoxetine in progressive multiple sclerosis: The FLUOX-PMS trial