Fluoxetine oral capsule interactions: Alcohol, medications, and other factors

Fluoxetine interactions with other medications

Before you start treatment with fluoxetine, tell your doctor and pharmacist about any prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether fluoxetine interacts with supplements, herbs, or vitamins, see the “Fluoxetine and other interactions” section.)

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Here’s a table of drugs that can interact with fluoxetine. Keep in mind that this table doesn’t include all drugs that may interact with fluoxetine. Some of these interactions are described in detail in “Drug interactions in depth.”

* Note: Taking these drugs with fluoxetine is contraindicated. For more information, see the “When to avoid fluoxetine” section.

When to avoid fluoxetine

In some cases, factors or conditions could prevent your doctor from prescribing fluoxetine due to the risk of harm. These are known as contraindications. Fluoxetine contraindications include:

Taking an MAOI

Doctors typically will not prescribe fluoxetine in combination with an MAOI (a type of antidepressant).

This is because taking fluoxetine with an MAOI can increase your risk of serotonin syndrome. With this syndrome, your body has a high level of a chemical called serotonin. This can cause symptoms such as blood pressure changes, excessive sweating, and diarrhea, nausea, or vomiting. Serotonin syndrome can be life threatening for some people.

Below are a few examples of MAOIs that can interact with fluoxetine:

• methylene blue (Provayblue)
• linezolid (Zyvox)
• phenelzine (Nardil)
• selegiline (Emsam)
• isocarboxazid (Marplan)

Before you start treatment with fluoxetine, it’s important to tell your doctor if you take an MAOI. They’ll likely have you stop taking the MAOI and wait at least 2 weeks before starting treatment with fluoxetine. Likewise, after you stop taking fluoxetine, your doctor will typically have you wait at least 5 weeks before starting treatment with an MAOI.

Taking the medications pimozide or thioridazine

Doctors typically will not prescribe fluoxetine if you’re taking thioridazine or pimozide. Thioridazine, pimozide, and fluoxetine can all cause long QT syndrome as a side effect when taken on their own. Long QT syndrome is a heart condition that affects your heart’s electrical system. It can be life threatening for some people. Taking these medications together further increases this risk, and the benefits typically do not outweigh the risks.

Due to this risk, your doctor can recommend a different treatment than thioridazine or pimozide that’s safer to take with fluoxetine. Or they can recommend a different treatment than fluoxetine.

Fluoxetine interaction with alcohol

The drugmaker of fluoxetine recommends avoiding alcohol consumption while taking the medication. Both fluoxetine and alcohol can impair thinking, judgment, and motor skills when taken on their own. Combining the two raises your risk of experiencing these side effects and how severe they can become.

If you have concerns about avoiding alcohol while you’re taking fluoxetine, talk with your doctor before starting treatment.

Drug interactions in depth

Here’s a closer look at certain drug interactions of fluoxetine.

NSAIDs

Fluoxetine may interact with NSAIDs, which are used to reduce mild to moderate short-term pain and inflammation.

Interaction result: Taking fluoxetine and an NSAID together can increase the risk of bleeding as a side effect of fluoxetine and NSAIDs.

Interaction explained: When taken on their own, both fluoxetine and NSAIDs increase the risk of bleeding. This risk further increases if these medications are taken together.

Examples of NSAIDs: Here are some NSAIDs that may interact with fluoxetine:

• aspirin
• ibuprofen
• naproxen (Naprosyn)
• diclofenac (Cataflam, others)
• indomethacin (Indocin)

Steps you or your doctor may take: If your doctor or pharmacist agrees, it may be safe to take an NSAID short-term while taking fluoxetine. This may depend on other risk factors, such as other medical conditions you may have or medications you may take.

If your doctor prescribes an NSAID for long-term treatment and you’re also taking fluoxetine, talk with them about ways to monitor yourself for bleeding. Some bleeding, such as internal bleeding, may not cause obvious symptoms. Your doctor can advise you on ways to monitor this side effect.

Certain antipsychotic medications

Fluoxetine can interact with certain antipsychotic medications. Antipsychotics are prescribed to treat certain mental health conditions such as schizophrenia.

Interaction result: Taking fluoxetine and certain antipsychotic medications together can increase the risk of long QT syndrome as a side effect of fluoxetine and certain antipsychotics.

Interaction explained: Both fluoxetine and certain antipsychotic medications can cause long QT syndrome as a side effect when taken on their own. If these medications are taken together, the risk of this side effect is further increased. The risk of severe symptoms of this side effect, such as cardiac arrest and seizures, also increases.

Examples of antipsychotic drugs: Here are some antipsychotic medications that may interact with fluoxetine:

• thioridazine
• pimozide
• ziprasidone (Geodon)
• iloperidone (Fanapt)

Steps you or your doctor may take: Certain antipsychotics have a higher risk of causing long QT syndrome, and doctors typically will not prescribe them together with fluoxetine. For example, thioridazine and pimozide generally should not be taken together with fluoxetine. For more information, see the “When to avoid fluoxetine” section.

If you need to take an antipsychotic medication with fluoxetine, your doctor can help suggest one with a lower risk of causing long QT syndrome. For example, fluoxetine and the antipsychotic medication olanzapine are available together in one pill called Symbyax. Although olanzapine can cause long QT syndrome, the risk may be lower compared to some other antipsychotics.

SNRIs

Fluoxetine can interact with SNRIs. Like fluoxetine, SNRIs are antidepressants prescribed for depression, anxiety disorders, and other conditions.

Interaction result: Taking fluoxetine and an SNRI together can increase the risk of serotonin syndrome as a side effect of fluoxetine and SNRIs.

Interaction explained: Both fluoxetine and SNRIs work by affecting serotonin levels in your system. But if they’re taken together, they can lead to serotonin syndrome (a condition characterized by excessive serotonin in your system). In rare instances, serotonin syndrome can be life threatening.

Examples of SNRI drugs: Here are some SNRIs that may interact with fluoxetine:

• duloxetine (Cymbalta)
• levomilnacipran (Fetzima)
• venlafaxine (Effexor XR)
• milnacipran (Savella)
• desvenlafaxine (Pristiq)

Steps you or your doctor may take: Doctors typically will not prescribe fluoxetine and an SNRI together. These medications work in similar ways. And combining them typically does not work better for treating depression or other mental health conditions compared to taking fluoxetine or an SNRI on their own.

Fluoxetine and other interactions

Fluoxetine may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with fluoxetine.

Fluoxetine interactions with supplements

Before you start treatment with fluoxetine, tell your doctor and pharmacist about any supplements, herbs, and vitamins you take. By sharing this information with them, you may help prevent possible interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Fluoxetine interactions with herbs

Doctors will typically recommend you avoid taking St. John’s wort with fluoxetine. St. John’s wort is an herbal supplement that may be used to treat depression and other conditions. Taking fluoxetine and St. John’s wort together raises your risk of serotonin syndrome as a side effect.

Fluoxetine also interacts with the herbal supplement valerian root, which may be used to aid sleep. Taking fluoxetine and valerian root can raise your risk of central nervous system (CNS) depression as a side effect. The combination also increases the risk of having severe symptoms of CNS depression.

Talk with your doctor to learn more about the possible risks if these herbal supplements are taken together with fluoxetine.

Fluoxetine interactions with vitamins

There are no specific reports of vitamins interacting with fluoxetine. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with fluoxetine.

Fluoxetine interactions with food

There were no reports of food interactions with fluoxetine. If you’d like to learn more about eating certain foods during treatment with fluoxetine, talk with your doctor.

Fluoxetine interactions with vaccines

There aren’t any known interactions between fluoxetine and vaccines. Talk with your doctor or pharmacist to see whether you’re due for any vaccines.

Fluoxetine interactions with lab tests

Fluoxetine isn’t known to interact with any lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor.

FLUOXETINE INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have been specifically reported to interact with fluoxetine. Taking fluoxetine can increase the risk of side effects of cannabis, including CNS depression. This occurs because fluoxetine can weaken your body’s ability to break down cannabis. When this happens, the level of cannabis in your system increases, which raises your risk of side effects.

Before you start treatment with fluoxetine, tell your doctor and pharmacist if you use cannabis. By sharing this information with them, you may help prevent possible interactions.

Note: Cannabis is illegal at a federal level but is legal in many U.S. states to varying degrees.

Fluoxetine and health-related interactions

Certain medical conditions and other factors may increase the risk of interactions with fluoxetine. Before you take this drug, be sure to talk with your doctor about your health history. Fluoxetine may not be the right treatment option if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with fluoxetine include:

• Bleeding problem: Fluoxetine increases your risk of bleeding. If you have a bleeding condition such as hemophilia, you may have an increased risk of bleeding if you take fluoxetine. Your doctor can help determine if fluoxetine treatment is safe for you.
• Liver problem: Your liver plays a key role in getting rid of fluoxetine after you take a dose. If you have a liver condition such as cirrhosis, the amount of fluoxetine in your system may build up. This can increase your risk of side effects of fluoxetine. If you have a liver condition, your doctor can help determine if it’s safe for you to take fluoxetine. They may prescribe you a lower fluoxetine dose.
• Long QT syndrome: Treatment with fluoxetine can cause long QT syndrome. If you already have long QT syndrome, taking fluoxetine may worsen your condition. Talk with your doctor to learn more about whether it’s safe for you to take fluoxetine.
• Low blood sodium level: Fluoxetine can cause low blood sodium level as a side effect. If you already have this condition, it may be worsened if you take fluoxetine. If your doctor prescribes fluoxetine to you, they may closely monitor your blood sodium level throughout treatment.
• Seizures: Seizures have rarely been reported as a side effect of fluoxetine. If you already experience seizures due to epilepsy or another condition, they may worsen or happen more often if you take fluoxetine. Your doctor can determine whether fluoxetine is safe for you to take.
• Allergic reaction: If you’ve had an allergic reaction to fluoxetine or any of its ingredients, your doctor will likely not prescribe fluoxetine. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.
• Breastfeeding: Fluoxetine passes into breast milk and may cause side effects in a child who is breastfed. These side effects can include irritability and poor feeding. If you’re breastfeeding or planning to, talk with your doctor before taking fluoxetine. They can discuss treatment options and ways to feed a child who is breastfed.
• Pregnancy: There are risks to taking fluoxetine while pregnant, but there are also risks caused by stopping an antidepressant, such as fluoxetine, during pregnancy. If you’re pregnant or planning to become pregnant, tell your doctor before starting fluoxetine. They can advise the right treatment plan for you.
• Risk of suicidal thoughts and behaviors: Fluoxetine has a boxed warning about the risk of suicidal thoughts and behaviors. This is a serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous. For details, see the boxed warning at the top of this article.

Preventing interactions

You can take certain steps to help prevent interactions with fluoxetine. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

• Let them know if you drink alcohol or use cannabis.
• Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
• Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the fluoxetine label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions.

If fluoxetine doesn’t come with paperwork, you can ask your pharmacist to print a copy. If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with fluoxetine by taking it exactly as your doctor prescribes.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.