Fluoxetine is used to treat depression.
It may also be used to treat anxiety disorders such as panic disorder, obsessive-compulsive disorder (OCD), bulimia nervosa (an eating disorder), and premenstrual dysphoric disorder (mood disorders before menstrual period).
Fluoxetine may also be used together with other medicines to treat other mood disorders as decided by your doctor.
Take Fluoxetine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
You may take this medicine with or without food. Try to take it at the same time each day.
Fluoxetine is available as a tablet (as conventional or dispersible form), capsule (as conventional or delayed-release form), or oral solution.
If you are taking the oral solution, use the dropper or measuring device supplied with each bottle to measure out your dose.
If you are taking the delayed-release type of capsule (usually labelled as "DR"), swallow it whole. Do not divide, chew or crush the capsule.
If you are taking the dispersible tablet, disperse it in a half glass of water then drink the solution immediately. Alternatively, you may also swallow the tablet whole with a half glass of water. Do not crush or chew the tablet.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on your condition and response to the medication.
Fluoxetine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it suddenly as it may worsen your condition.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Alert your doctor if you have the following conditions:
- uncontrolled epilepsy (fits or seizures)
- severe kidney disease
as this medicine may not be suitable for you.
Do not take Fluoxetine with medicines used to treat depression known as monoamine oxidase inhibitors (MAOIs), medicines for mood disorder, blood disorder, heart failure, and certain antibiotic. Please see the section “Can I take it with other medicines?” below for more information.
Inform your doctor if you have the following conditions:
- history of having thoughts of self-harm
- bipolar disorder (mood changes between feeling very high and very low)
- history of mania (feeling highly excited, being over-active and easily irritated or distracted)
- epilepsy (fits or seizures) or predisposing conditions to fits or seizures e.g. brain damage, alcoholism
- heart disease e.g. recent heart attack
- history of bleeding problems
- glaucoma (increased pressure in the eye)
- liver disease
- mild to moderate kidney disease
Let your doctor know if you are pregnant or breastfeeding.
Be sure to check with your doctor or pharmacist before giving this medicine to a child or the elderly. Children and elderly people may be more sensitive to the side effects.
Do not switch dosage forms and brands unless instructed by your doctor. Different preparation and brands of Fluoxetine may vary on how it works in your body.
Notify your doctor if you have recently undergone electroshock therapy (also known as electroconvulsive therapy or ECT).
If you are going to have an operation, including minor surgery and dental work, inform your doctor or dentist that you are taking this medicine.
Medicines for depression such as Fluoxetine may increase the risk of suicidal thoughts and behaviour. As depression and some psychiatric disorders are themselves associated with an increased risk of suicide, it is important for you or your family members to monitor your condition especially at the start of treatment and if your dosage is still being adjusted. If you experience new or sudden changes in mood, behaviour, thoughts or feelings or a worsening of your depression with suicidal thoughts or attempts, harm to self or harm to others, contact your doctor immediately.
A certain enzyme called CYP2D6 is involved in the breakdown of this medicine in the body. Individuals who are known as poor metabolisers of CYP2D6 may experience enhanced side effects of this medicine (e.g. heart rhythm disorder). If you know you have this gene type, inform your doctor.
Why is it important to keep my appointments with the doctor?
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly, and may also perform routine tests (e.g. liver and kidney function, blood sugar levels) while you are being treated with this medicine. Your doctor will advise you about how often you need to have these tests.
What lifestyle changes should I make to cope with depression?
Regular exercise and eating a healthy diet will help increase energy and hormones in the body such as serotonin, endorphins and other feel-good chemicals that minimise mood swings. Get enough sleep, as lack of sleep may cause irritability, moodiness, sadness, and tiredness.
Fluoxetine may cause dizziness or drowsiness, if affected, do not drive or take part in any activity in which you need to be alert.
Other side effects may include any of the following: headache, blurred vision, sore throat, dry mouth, nausea, vomiting, diarrhoea, indigestion, changes in taste, loss of appetite, weight loss, difficulty sleeping, unusual dreams, nervousness, tiredness, joint pain, frequent urination, and skin itching.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- having thoughts of self-harm
- unusual changes in mood or behaviour (being too depressed, irritable, aggressive, anxious, or having compulsive and impulsive behaviour)
- feeling confused or agitated, fever, fast heartbeat, increased sweating, muscle stiffness
- irregular heartbeat, feeling faint, chest pain
- unusual bleeding or bruising
- restlessness, unable to sit or stand still, or need to move often
- fits or seizures
- changes in sex drive
- rashes, breathlessness, swollen face, eyes, tongue or throat
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Do not take Fluoxetine if you are currently taking or have taken a medicine to treat depression known as monoamine oxidase inhibitor (MAOI) such as iproniazid, isocarboxazid, phenelzine and tranylcypromine or within 2 weeks of stopping the MAOI. Do not take MAOI within 5 weeks of stopping Fluoxetine.
Do not take thioridazine (medicine for mood disorder) within 5 weeks of stopping this medicine.
Do not take Fluoxetine if you are taking or using any of the following medicines:
- pimozide (medicine for mood disorders)
- metoprolol (medicine for heart failure)
- linezolid (antibiotic)
- injectable methylene blue (medicine for certain blood disorder)
Inform your doctor and pharmacist if you are taking any of these medicines:
- other medicines for depression e.g. imipramine, desipramine, amitriptyline
- medicines for mood disorders e.g. lithium, clozapine, haloperidol, risperidone
- medicines for epilepsy (fits or seizures) e.g. phenytoin, carbamazepine
- medicines for migraine e.g. sumatriptan, zolmitriptan
- strong painkillers e.g. fentanyl, tramadol
- medicines for pain and inflammation e.g. aspirin, ibuprofen, diclofenac
- medicines for irregular heartbeat e.g. propafenone, flecainide, encainide
- medicines for cold or allergy e.g. mequitazine, astemizole, mizolastine, cyproheptadine
- certain antibiotics e.g. erythromycin, moxifloxacin, sparfloxacin
- warfarin (blood-thinning medicine)
- tamoxifen (medicine for breast cancer)
- St. John’s wort (herbal supplement)
This list does not include all medicines that may interact with Fluoxetine.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children. Protect from light, heat and moisture.
Medicines must not be used past the expiry date.