(Brand Name: Prozac, Sarafem)

The following information is a guide only and you must discuss your medication needs with a trained health professional.

Fluoxetine was discovered by Eli Lilly and Company in 1972 and entered medical use in 1986 and is available on prescription in either tablet or capsule form.

Key Facts:
  • It usually takes 4 to 6 weeks for Fluoxetine to work
  • Check with your doctor before starting to take Fluoxetine if you are trying to become pregnant, or plan to discontinue it if you’re already pregnant or you are breastfeeding
  • Take Fluoxetine once a day. You can take it with or without food
  • If you have an eye problem called glaucoma please tell your doctor because Fluoxetine can increase eye pressure
  • If you have diabetes, Fluoxetine can make it more difficult to keep your blood sugar stable. Monitor your blood sugar more often for the first few weeks of taking and consult your doctor
  • In the United States, the FDA require all antidepressants including Fluoxetine to carry a warning  that antidepressants may increase the risk of suicide in people younger than 25.

Medication Information

Skeletal formula of fluoxetine (original trade name Prozac)

Skeletal formula of fluoxetine (Prozac)

The following information is a guide only, a doctor may want to try dosages outside these recommended guides.

Form: Tablets or capsules.

When: At any time of day, although recommended you stick to the same time every day. If you have trouble sleeping, it’s best to take the medication in the morning.

Child dose: The usual dose for children is 10mg daily.

Adult dose: The usual dose for adults is 20mg daily, as a single dose,  however, it may be started at a lower dose and gradually increased to a maximum dose of 60mg a day.

Older people: Usually 20mg daily but can be increased to a maximum dose of 40mg a day.

Half-Life: Ranging from 1 to 3 days after a single dose, up to 4 to 6 days after long-term use. If you occasionally forget to take a dose, because of the long half-life don’t worry, take your next dose the next day at the usual time. Never take 2 doses at the same time to make up for a forgotten one.

Drug interactions: Don’t take St John’s wort, the herbal remedy, while you are taking Fluoxetine as this will increase your risk of side effects.

Pregnancy and Breast Feeding: It’s important for you and your baby that you stay well during your pregnancy. If you become pregnant while taking Fluoxetine speak to your doctor, it’s important not to stop taking your medicine unless your doctor tells you to.  Ask your doctor to discuss the potential benefits against potential risks of staying on medication whilst pregnant or breastfeeding so that you can make an informed choice about what is right for you and your baby. 

The NICE guidelines, published in November 2005, recommended that Fluoxetine should be used where there is significant co-morbid depression with OCD.


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