Fluoxetine belongs to a class of medications called selective serotonin reuptake inhibitors (SSRIs). It is used for the treatment of depression and helps to elevate mood. Selective serotoin reuptake inhibitors work by increasing the amount of a neurotransmitter called serotonin that is available in certain parts of the brain. Although you may start feeling better within a few weeks of treatment, the full effects of the medication may not be evident until several weeks of treatment have passed. Fluoxetine is also used to reduce or eliminate the symptoms of obsessive-compulsive disorder (OCD) as well as to treat the eating disorder, bulimia nervosa.

Your doctor may choose to use a medication for conditions other than the ones listed in these drug information articles. If you're unsure why you are taking this medication, contact your doctor.

The recommended adult dose of fluoxetine ranges from 20 mg to 60 mg taken once daily in the morning, with or without food. The maximum recommended dose of fluoxetine is 80 mg daily. Once your symptoms have been brought under control, the lowest effective dose of fluoxetine as prescribed by your doctor should be used to keep the symptoms from coming back. Your doctor may advise you to keep taking fluoxetine for several months.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is very important to take this medication exactly as prescribed by your doctor. If you forget a dose of the medication, skip the missed dose and carry on with your regular schedule. Do not double doses.

Prozac^® is available as capsules or as a liquid.

Capsules:
10 mg: Each green-and-grey capsule, printed with "Lilly 3104" and "Prozac 10 mg", contains fluoxetine 10 mg. Nonmedicinal ingredients: silicone and starch; capsule shell: benzyl alcohol, carboxymethylcellulose, edetate calcium disodium, FD&C Blue No. 1, gelatin, iron oxide black, iron oxide yellow, methylparaben, sodium, sodium lauryl sulfate, sodium propionate, and titanium dioxide.
20 mg: Each green-and-white capsule, printed with "Lilly 3105" and "Prozac 20 mg", contains fluoxetine 20 mg. Nonmedicinal ingredients: silicone and starch; capsule shell: benzyl alcohol, carboxymethylcellulose, edetate calcium disodium, FD&C Blue No. 1, gelatin, iron oxide yellow, methylparaben, sodium, sodium lauryl sulfate, sodium propionate, and titanium dioxide.

Liquid: Each 5 mL clear, colourless, syrup solution, with an odour of mint, contains fluoxetine 20 mg/5 mL. Nonmedicinal ingredients: benzoic acid, glycerin, mint flavor, purified water, and sucrose.

Fluoxetine should not be taken by anyone who:

• is allergic to fluoxetine or any of the ingredients of the medication
• has taken a medication known as a MAO inhibitor within the past 14 days

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor. Your health professional may be able to help you deal with some of the effects.

The following side effects may go away as your body becomes used to the medicine; check with your doctor if they continue or become bothersome.

More common:

• anxiety or nervousness
• decreased appetite
• diarrhea
• drowsiness
• headache
• increased sweating
• nausea
• tiredness or weakness
• trembling or shaking
• trouble sleeping

Less common or rare:

Check with your doctor as soon as possible if any of the following side effects occur:

More common:

• decreased sexual drive or ability
• inability to sit still, or restlessness
• skin rash, hives, or itching

Less common:

• chills or fever
• joint or muscle pain

Rare:

• breast enlargement or pain
• convulsions (seizures)
• fast or irregular heartbeat
• purple or red spots on skin
• symptoms of hypoglycemia (low blood sugar), including:
  • anxiety or nervousness
  • chills
  • cold sweats
  • confusion
  • cool pale skin
  • difficulty concentrating
  • drowsiness
  • excessive hunger
  • fast heartbeat
  • headache
  • shakiness or unsteady walk
  • unusual tiredness or weakness
• symptoms of hyponatremia (low blood sodium), including:
  • confusion
  • convulsions (seizures)
  • drowsiness
  • dryness of mouth
  • increased thirst
  • lack of energy
• symptoms of serotonin syndrome, including:
  • diarrhea
  • fever
  • increased sweating
  • mood or behaviour changes
  • overactive reflexes
  • racing heartbeat
  • restlessness
  • shivering or shaking
• talking, feeling, and acting with excitement and activity you cannot control
• trouble breathing
• unusual or incomplete body or facial movements
• unusual secretion of milk (females)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Allergy: Approximately 4% of people who take fluoxetine develop a rash or hives. Almost one-third of these people need to stop treatment because of the rash.

Diabetes: For people with diabetes, fluoxetine may alter blood glucose control. Low blood glucose has occurred during therapy with fluoxetine and high blood glucose has developed after treatment stops. As is true for many other types of medication when taken by people with diabetes, dosages of insulin or anti-diabetic tablets may need adjustment when therapy with fluoxetine starts or stops.

Epilepsy: Fluoxetine should be used with caution by people with epilepsy.

Occupational hazards: People taking fluoxetine are cautioned against driving a car or performing hazardous tasks until they determine that this medication does not affect them adversely.

Pregnancy: The safe use of fluoxetine during pregnancy has not been established. It should not be used by pregnant women unless the potential benefits outweigh the risks.

Breast-feeding: Fluoxetine passes into breast milk. It should not be used by nursing women unless, in the opinion of their doctor, both the medication and breast-feeding are necessary.

Children: The safety and effectiveness of this medication for children and adolescents younger than 18 years of age have not been established.

• alcohol
• buspirone
• carbamazepine
• clarithromycin
• dextromethorphan
• levodopa
• lithium
• meperidine
• MAO inhibitors
• nefazodone
• other SSRIs (e.g., paroxetine, fluvoxamine)
• sumatriptan
• St. John's wort
• tricyclic antidepressants
• tryptophan
• valproic acid
• divalproex

The following medications may be affected by fluoxetine:

• astemizole
• antipsychotics (e.g., haloperidol, risperidone, clozapine)
• benzodiazepines
• carbamazepine
• digoxin
• metoprolol
• nifedipine
• phenobarbital
• propranolol
• phenytoin
• tricyclic antidepressants (e.g., desipramine, imipramine)
• terfenadine
• verapamil
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.