What is fluoxetine?
Fluoxetine is an antidepressant medication used to treat depression, obsessive-compulsive disorder, and bulimia. It is an SSRI (Selective Serotonin Reuptake Inhibitor), which means that it works by increasing the amount of serotonin in the brain.
It is only available on prescription and comes in the form of tablets and capsules.
Fluoxetine is the generic name for the drug. It is also sold under the brand name Prozac, amongst others.
How long does it take for fluoxetine to start to work?
Fluoxetine usually takes 4-6 weeks to start working. If you’ve recently started taking fluoxetine and feel that it isn’t working, it’s best to keep taking it for at least six weeks to see if it starts to work. If after six weeks you’re still not feeling any better, talk to your doctor. They may suggest increasing your dose or switching to a different antidepressant.
Some people find that they feel worse in the first couple of weeks of taking fluoxetine, before starting to feel better after a few weeks. If you’ve recently started fluoxetine and feel that it’s making your symptoms worse, you can try to stick it out as this usually goes away after a few weeks.
However, if at any point you begin to experience thoughts of suicide or harming yourself, you must see a doctor immediately.
I’m experiencing side effects while taking fluoxetine. What ways can I try to help cope with them?
Some people experience side effects while taking fluoxetine. Usually, these side effects are fairly mild and common and may get better over time as your body gets used to the fluoxetine.
Here are some common side effects and ways to cope with them:
- Nausea – take fluoxetine with or after food, and avoid rich or spicy foods.
- Headaches – rest and drink plenty of water. If you feel that it would help to take a painkiller, ask a doctor or pharmacist to recommend one which can be taken alongside fluoxetine. If your headaches don’t go away after a week or they become more severe, see a doctor.
- Trouble sleeping – take fluoxetine first thing in the morning, so that this side effect has hopefully mostly worn off by the time you go to bed.
- Diarrhea – stay hydrated and drink plenty of water. It may help to take oral rehydration solutions, which you can find in pharmacies.
- Feeling tired – take fluoxetine at night, just before you go to bed
(For tips on how to cope with sexual side effects, please go to question 5. “Fluoxetineis affecting my sex life. How can I deal with sexual side effects?”)
Some side effects are serious, and you should speak to a doctor immediately if you experience any of them:
- Thoughts of suicide or self-harm
- Headache, trouble focusing, memory problems, seizures, losing your balance, or feeling weak – these may be signs of low sodium levels
- Chest pain or shortness of breath
- Severe dizziness or fainting
- Feelings of euphoria, excessive enthusiasm or excitement, or feeling restless
- Unexpected changes in your weight
- Changes in your periods such as heavy bleeding, or spotting or bleeding between periods
- Painful erections that last for more than four hours (priapism)
- Abnormal bleeding, such as bloody stool or unexplained bruises
It is also important to be aware of the signs of an allergic reaction. If you experience an allergic reaction to fluoxetine, you must see a doctor immediately.
- Signs of a serious allergic reaction include:
- Skin rash – for example itchy, red, or swollen skin
- Tightness in the chest or throat
- Trouble breathing or talking
- Swollen mouth, face, lips, tongue, or throat
What are the signs of fluoxetine overdose?
If you think you have taken too much fluoxetine, talk to your doctor immediately. Signs of fluoxetine overdose include:
- Nausea and vomiting
- Feeling shaky
- Feeling sleepy
- High fever
- Fast heart rate
- Trouble breathing
- Stiff muscles
- Constant, uncontrollable muscle spasms
💡 Don’t forget to take fluoxetine, use the MyTherapy app to track your treatment and set alerts.
Fluoxetine is affecting my sex life. How can I cope with sexual side effects?
Fluoxetine, like several other antidepressants, can cause sexual side effects. A common side effect is decreased sex drive, and sometimes difficulty achieving orgasm. Men may also experience erectile dysfunction and find it difficult to develop or maintain an erection.
There are a few things you can try to help cope with sexual side effects.
You can wait and see if these side effects go away on their own – antidepressant side effects often appear when you first start taking a new medication or a higher dose and usually go away after a few weeks.
You may also try taking fluoxetine after the usual time that you have sex, particularly if you are experiencing lowered libido after taking fluoxetine. The concentration of fluoxetine is usually at its highest in your body soon after you take it, so this method may help you avoid the sexual side effects caused by fluoxetine.
If this doesn’t help, talk to your doctor. They may suggest reducing your dose, which can sometimes help to lower side effects. Talk to your doctor if you would like to try this – never change your dose of medication without speaking to a doctor first.
Alternatively, your doctor may suggest switching to a different antidepressant or adding another medication, for example, to help with erectile dysfunction in men.
Are there any long term side effects of taking fluoxetine?
Aside from the previously mentioned side effects, fluoxetine is generally considered safe to take for a long time. A possible link between SSRIs and an increased risk of type 2 diabetes and an adverse effect on glucose metabolism has been explored, but there is a lack of substantial evidence regarding the possible connection. If you have concerns about your risk of developing type 2 diabetes or glycemic control, these should be discussed with your doctor.
When is the best time of day to take fluoxetine?
You can take fluoxetine at any time of the day, but you must take it at the same time every day.
If you are experiencing side effects on fluoxetine, it may help to take it at a particular time of day to try to avoid the worst of the side effects. For example, if fluoxetine gives you trouble sleeping, it may help to take fluoxetine first thing in the morning so that it’s hopefully worn off a bit by the time you go to bed.
On the other hand, if fluoxetine makes you sleepy or gives you other unpleasant side effects, try taking it just before bedtime so that you’re asleep when the concentration of the medication is at its highest in your body.
I’d like to stop taking fluoxetine. How can I safely wean myself off fluoxetine? Will I experience withdrawal?
If you’d like to come off fluoxetine, it’s very important that you talk to your doctor first. Never stop taking medication without first discussing it with your doctor. Your doctor will help you to safely wean yourself off fluoxetine by gradually reducing your dose of fluoxetine over time, to slowly taper off the medication.
Don’t stop taking medication abruptly, as this can cause withdrawal symptoms such as dizziness, nausea, trouble sleeping, headaches, shaking, feeling anxious, and numbness or tingling in your hands and feet.
💡 Healthcare doesn’t have to be a solo effort. Take advantage of the MyTherapy App’s team features and include caretakers, doctors, and family in your treatment.
Will fluoxetine affect my birth control?
No. Fluoxetine does not affect any type of birth control, including contraceptive pills and the morning after pill. Talk to your doctor or pharmacist if you have concerns about fluoxetine interacting with your contraception or any other medications you are taking.
Can I take fluoxetine while pregnant?
This is something that you must discuss with your doctor. Always tell your doctor if you are taking medications and become pregnant.
Generally, it’s advisable to avoid taking fluoxetine during pregnancy unless it’s really necessary, as it has been linked to a very small increased risk of problems for the baby. However, it is also important to remain well during pregnancy, and this may mean that it’s necessary for you to continue taking fluoxetine.
Talk to your doctor if you are taking fluoxetine and are planning to become pregnant or have become pregnant. They will help you weigh up the benefits of fluoxetine to your health, against the possible risks to you and your baby. If necessary, they will help you to safely wean yourself off fluoxetine by gradually reducing your dose over a period of time. Don’t stop taking your medication abruptly without talking to a doctor first.
Can I take fluoxetine while breastfeeding?
This is something that you must discuss with your doctor. Fluoxetine is generally thought to be relatively safe to take while breastfeeding if your baby is healthy. It is known to pass into the breast milk in small amounts and may lead to side effects in a very small number of babies.
However, it is important to stay well for yourself and your baby. Talk to your doctor and they will help you weigh up the relative risks and benefits to yourself and your baby, and so that you can decide whether it’s best to stay on fluoxetine or come off it.
If you do decide to stay on fluoxetine, talk to your doctor immediately if you notice that your baby isn’t feeding as well as usual or seems unusually sleepy.
Can I drive while on fluoxetine?
Some people find that fluoxetine affects their concentration, so if you’ve recently started taking fluoxetine, it’s best to avoid driving for a few days until you’ve seen how fluoxetine makes you feel.
Can I have coffee or other caffeinated drinks while on fluoxetine?
It’s generally safe to have coffee and caffeinated drinks while on fluoxetine. However, you should avoid drinking a lot of coffee or other caffeinated drinks such as cola and energy drinks, because it may increase the risk of getting a rare but dangerous condition called serotonin syndrome. Symptoms of serotonin syndrome include fever, agitation, confusion, trembling, sweating, diarrhea, fast heartbeat, hallucinations, seizures, or blurred vision. If you experience any of these symptoms, you must see a doctor immediately.
Can I drink alcohol while on fluoxetine?
Generally, it is safe to have alcohol while taking fluoxetine, but it may make you feel more sleepy than usual. If you’ve recently started taking fluoxetine, it’s a good idea to avoid alcohol until you’ve seen how fluoxetine makes you feel.
Can I take recreational drugs such as marijuana, MDMA, LSD or cocaine while on fluoxetine?
It’s best not to take recreational drugs while on fluoxetine, as it hasn’t been properly tested with recreational drugs, so it’s not really known how they may react with each other or whether it’s safe to take them together.
Marijuana (cannabis) may make you feel more drowsy when taken together with fluoxetine, particularly if you’ve recently started taking fluoxetine. It may also cause a fast heartbeat.
Methadone may also make you feel more drowsy when taken together with fluoxetine. Fluoxetine can cause an unintended increase in the level of methadone in your body.
It is particularly dangerous to take cocaine, MDMA (ecstasy) or amphetamines while on fluoxetine, because they may cause a rare but dangerous condition called serotonin syndrome. Signs of serotonin syndrome include fever, agitation, confusion, trembling, sweating, diarrhea, fast heartbeat, hallucinations, seizures, or blurred vision. If you experience these symptoms, you must see a doctor immediately. It is important to tell them everything you have taken so that they can treat you correctly.
If you think you may take recreational drugs while on fluoxetine, talk to your doctor for advice on how to do this as safely as possible.
Can I take painkillers such as ibuprofen, naproxen, paracetamol, or aspirin while on fluoxetine?
If you need to take a painkiller while on fluoxetine, ask a doctor or pharmacist to recommend one which is safe for you to take.
It’s generally safe to take paracetamol with fluoxetine. However, you should avoid taking aspirin or NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen or naproxen, unless your doctor has advised you to take it alongside your fluoxetine. This is because they can cause an increased risk of bleeding when taken together with fluoxetine.
It is fine to take aspirin or an NSAID with fluoxetine if your doctor has prescribed this combination of medications and has agreed that the benefits to your health outweigh the risks of taking these medications together.
💡 Getting the most out of your fluoxetine treatment means understanding your own health. The MyTherapy app helps you to track, visualize, and organize health data such as your mood in a way that works for you.
Can I take Adderall together with fluoxetine?
Don’t take fluoxetine together with Adderall without speaking to your doctor first. This is because fluoxetine can increase the effects of amphetamine, causing side effects such as feeling jittery, nervousness, anxiety, restlessness, and racing thoughts. There may also be an increased risk of getting a rare but serious condition called serotonin syndrome. Symptoms of serotonin syndrome include fever, agitation, confusion, trembling, sweating, diarrhea, fast heartbeat, hallucinations, seizures, or blurred vision. If you experience these symptoms, you must see a doctor immediately.
Can I take Benadryl together with fluoxetine?
Don’t take Benadryl together with fluoxetine without first checking with a doctor or pharmacist. This is because Benadryl contains the active ingredient diphenhydramine, which when taken together with fluoxetine may lead to increased side effects such as dizziness, drowsiness, confusion, and difficulty concentrating.
Talk to a doctor or pharmacist if you would like further advice on sleep aids or allergy medication which can be taken together with fluoxetine.
Can I take Nyquil together with fluoxetine?
No, you should not take Nyquil while on fluoxetine. This is because most types of Nyquil contain the active ingredient dextromethorphan (amongst others), which should not be taken together with fluoxetine as fluoxetine can cause an unintended increase in the level of dextromethorphan in your body, increasing the effects of dextromethorphan. This can lead to symptoms such as trouble breathing, dizziness, feeling sleepy, anxiety, restlessness, confusion, or diarrhea. If you experience these symptoms, you must see a doctor.
Talk to a doctor or pharmacist for advice on what types of sleep aids or cold and flu medication can be safely taken together with fluoxetine.
💡 Treatment with fluoxetine can be complex and patient feedback can help doctor’s make the best decisions for patients. Using the MyTherapy app is a great way to keep track of and export relevant information to healthcare providers.
Can I take Ambien together with fluoxetine?
Don’t take Ambien while on fluoxetine without speaking to a doctor or pharmacist first. This is because Ambien contains the active ingredient zolpidem, which when taken together with fluoxetine may lead to increased side effects such as dizziness, drowsiness, confusion, and difficulty concentrating. Some people may also experience impaired thinking or have trouble with motor coordination.
Talk to a doctor or pharmacist if you would like further advice on sleep aids which can be taken together with fluoxetine.
The content on this page is provided for informational purposes only. If you have any questions or concerns about your treatment, you should talk to your doctor, pharmacist, or healthcare professional. This is particularly important if you are taking multiple medications or have any existing medical conditions.