Prozac interactions: Alcohol, medications, and other factors

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

Taking pimozide

Before starting Prozac treatment, tell your doctor if you take pimozide. The drug is an antipsychotic used to treat Tourette syndrome.

Taking Prozac in combination with pimozide may increase your risk of serious side effects from either drug.* Specifically, you may have an increased risk of heart problems, including irregular heart rhythm.

Due to this risk, doctors typically will not prescribe Prozac with pimozide. If you take pimozide, talk with your doctor before taking Prozac. They can recommend a different treatment option for your condition.

* For details about the side effects of Prozac, see this article.

Taking thioridazine

Before starting Prozac treatment, tell your doctor if you take thioridazine. This is an antipsychotic drug used to treat schizophrenia.

Taking Prozac with thioridazine may increase your risk of heart problems from either drug.* This includes heart conditions such as irregular heart rhythm.

Due to this risk, doctors typically will not prescribe Prozac in combination with thioridazine. If you take thioridazine, your doctor can recommend a treatment other than Prozac.

* For details about the side effects of Prozac, see this article.

Taking a monoamine oxidase inhibitor

Before starting Prozac treatment, tell your doctor if you take an antidepressant called a monoamine oxidase inhibitor (MAOI).

Taking Prozac with an MAOI may increase your risk of serotonin syndrome as a side effect of either drug.* This syndrome is caused by a high level of the chemical serotonin in the body. Serotonin syndrome can cause symptoms such as diarrhea, vomiting, excessive sweating, and blood pressure changes. This syndrome can be life threatening in extreme cases.

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

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

Due to this risk, doctors typically will not prescribe Prozac with an MAOI. If you take an MAOI, your doctor may have you stop taking it and wait at least 2 weeks to start Prozac.

If your doctor switches you from Prozac to an MAOI, they’ll typically have you wait at least 5 weeks before starting treatment with an MAOI.

* For details about the side effects of Prozac, see this article.

Note: Before you start treatment with Prozac, it’s important to tell your doctor if these contraindications apply to you. They can determine whether to prescribe Prozac.

There’s no known interaction between Prozac and alcohol.

However, the manufacturer of Prozac recommends that you avoid drinking alcohol while taking this drug. This is because alcohol can worsen certain side effects of Prozac. Examples include dizziness and sleepiness. For information about the side effects of Prozac, refer to this article.

If you drink alcohol and have questions about drinking it while taking Prozac, talk with your doctor or pharmacist.

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

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 Prozac. Keep in mind that this table doesn’t include all drugs that may interact with Prozac. Some of these interactions are described in detail just below in “Drug interactions in depth.”

* For details about this interaction, see the “When to avoid Prozac” section above.
† For details about the side effects of Prozac, see this article.

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

Tricyclic antidepressants

Tricyclic antidepressants (TCAs) are used to treat depression and certain other mental health conditions.

Interaction result. Taking Prozac with TCAs can increase the risk of side effects from either drug. For details about the side effects of Prozac, see this article.

Interaction explained. Prozac is a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI). It works by affecting the level of a chemical called serotonin in the body. TCAs also affect the level of this chemical.

A very high level of serotonin in the body could lead to serotonin syndrome, which can be life threatening in extreme cases. Serotonin syndrome can cause symptoms such as diarrhea, vomiting, excessive sweating, and blood pressure changes. Taking Prozac with TCAs could further increase your risk of serotonin syndrome.

In addition, Prozac and TCAs may cause a type of irregular heart rhythm called long QT syndrome. This condition may not cause symptoms but can be measured using an EKG. Taking these medications together could increase the risk of this side effect.

Examples of TCA drugs. Here are some TCAs that may interact with Prozac:

• amitriptyline
• clomipramine (Anafranil)
• imipramine (Tofranil)
• nortriptyline (Pamelor)
• trimipramine

Steps you or your doctor may take. Before starting Prozac treatment, tell your doctor if you take a TCA. They can also help identify whether any of your medications are TCAs. Your doctor can advise you on whether it’s safe for you to take these medications together.

If your doctor does prescribe Prozac with a TCA, watch for symptoms of serotonin syndrome. They may also occasionally check your heart rhythm with an EKG. Your doctor will instruct you on managing any side effects if they happen.

Lithium

Lithobid (lithium) is a mood stabilizer used to treat bipolar disorder.

Interaction result. Taking Prozac with lithium can increase the risk of side effects from either drug. (For details about the side effects of Prozac, see this article.) Taking these medications together could also make lithium less effective.

Interaction explained. Prozac and lithium work by affecting the level of a chemical called serotonin in the body.

Having a very high level of serotonin in the body could lead to serotonin syndrome. Symptoms of this syndrome may include diarrhea, vomiting, excessive sweating, and blood pressure changes. In extreme cases, serotonin syndrome can be life threatening.

Prozac and lithium may also cause an irregular heart rhythm called long QT syndrome, which can be measured using an EKG.

As a result, taking Prozac with lithium can increase your risk of serotonin syndrome and long QT syndrome as side effects.

In addition, the effect of Prozac on lithium blood levels can vary from person to person. For example, Prozac may raise or lower the level of lithium in your body. A higher level of lithium could increase your risk of side effects from the drug. On the other hand, a decreased level of lithium could cause the drug to be less effective.

Steps you or your doctor may take. Before starting Prozac treatment, tell your doctor if you take lithium. They can advise you on whether it’s safe for you to take these medications together.

If your doctor does prescribe Prozac with lithium, watch for symptoms of serotonin syndrome. They may also periodically check your heart rhythm with an EKG and check your lithium blood levels more often than usual. Your doctor will instruct you on how to manage side effects of Prozac and lithium if they happen.

Dextromethorphan

Delsym (dextromethorphan) is a cough suppressant.

Interaction result. Taking Prozac with Delsym can increase the risk of side effects from either drug. (For details about the side effects of Prozac, see this article.)

Interaction explained. Prozac slows down the activity of an enzyme called cytochrome P450 2D6 (CYP2D6). An enzyme is a type of protein.

CYP2D6 helps break down Delsym in the body. As a result, taking Prozac with Delsym can raise the level of Delsym in your body. This may increase your risk of side effects from Delsym, including serotonin syndrome.

With serotonin syndrome, you have a high level of the chemical serotonin in the body. This syndrome can cause symptoms such as diarrhea, vomiting, excessive sweating, and blood pressure changes. Serotonin syndrome can be life threatening in extreme cases.

Prozac may also cause serotonin syndrome as a side effect. As a result, your risk of serotonin syndrome is even higher if Prozac and Delsym are taken together.

Steps you or your doctor may take. Delsym is available over the counter (OTC), meaning you don’t need a prescription from a doctor to buy it. The drug is available alone and in combination with other drugs in many OTC cold medications.

If you need a cough suppressant while taking Prozac, talk with your doctor or pharmacist. They can advise you on which medications are safe to take with Prozac.

Prozac 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 Prozac.

Prozac interactions with supplements

Before you start treatment with Prozac, tell your doctor and pharmacist which 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.

Prozac interactions with herbs

Prozac may interact with the supplements St. John’s wort and tryptophan.

Taking either supplement during Prozac treatment may increase your risk of serotonin syndrome as a side effect of Prozac.*

Having a high level of a chemical called serotonin in your body can lead to serotonin syndrome. This condition can cause serious and possibly life threatening side effects for some people.

Before taking any herbal products with Prozac, talk with your doctor or pharmacist.

* For information about the side effects of Prozac, see this article.

Prozac and vitamins

There are no specific reports of vitamins interacting with Prozac. 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 Prozac.

Prozac and food

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

Prozac and vaccines

There are no specific reports of vaccines interacting with Prozac. To learn more about getting certain vaccines during Prozac treatment, talk with your doctor.

Prozac and lab tests

There are no specific reports of lab tests interacting with Prozac. To learn more about getting specific lab tests during Prozac treatment, talk with your doctor.

PROZAC INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have been specifically reported to interact with Prozac. Taking Prozac with cannabis or cannabis products may increase the risk of side effects with cannabis.

Before you start treatment with Prozac, 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.

Certain medical conditions and other factors may increase the risk of interactions with Prozac. Before you take this drug, be sure to talk with your doctor about your health history. Prozac 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 Prozac include:

• Being younger than age 25 years. Prozac may increase the risk of suicidal thoughts and behaviors. This risk is highest in adults younger than age 25 years and children. In fact, the drug has a boxed warning about this risk. This is a serious warning from the Food and Drug Administration (FDA). For more information, see “Boxed warning: Risk of suicidal thoughts and behaviors” at the top of this article.
• Mania or bipolar disorder. If you have mania or bipolar disorder, taking Prozac may increase your risk of a manic or mixed episode. Before starting Prozac treatment, tell your doctor about any mental health conditions you have. They can recommend whether Prozac is a safe treatment option.
• Liver problems. If you have a liver problem, such as cirrhosis, tell your doctor before starting Prozac treatment. People with liver problems may have a higher risk of side effects from the drug. For this reason, your doctor may prescribe a lower dosage of Prozac than usual.
• Heart problems. Prozac may cause long QT syndrome. Your risk for this side effect may be higher if you have certain heart problems. Examples include heart failure, a recent heart attack, or an irregular heart rhythm. Before taking Prozac, tell your doctor about any heart problems you have. They can recommend whether it’s safe for you to take Prozac.
• Seizures. Prozac may cause seizures as a side effect. Your risk for this side effect may be higher if you have a seizure disorder, such as epilepsy. Before taking Prozac, tell your doctor if you have a seizure disorder. They can recommend whether Prozac is safe to take.
• Diabetes. If you have diabetes, be sure to tell your doctor before starting Prozac treatment. The drug can make it hard to manage your blood sugar level. If you take Prozac, your doctor may have you check your blood sugar level more often than usual.
• Bleeding problems. Before starting Prozac treatment, tell your doctor if you have a bleeding problem such as hemophilia. Prozac may increase your risk of bleeding. And this risk may be even greater in people with bleeding problems. Your doctor can advise whether Prozac is the right treatment option for your condition.
• Low sodium, magnesium, or potassium levels in the blood. Before taking Prozac, your doctor may check the levels of electrolytes in your blood. If you have a low sodium, magnesium, or potassium level, your doctor may give you treatments to increase them before starting Prozac treatment. This is because Prozac may cause low sodium as a side effect, which could make your sodium level even lower. And having low magnesium or potassium levels could increase your risk of long QT syndrome as a side effect of Prozac.
• Pregnancy. Selective serotonin reuptake inhibitors (SSRIs), including Prozac, may not be safe to take during the last 3 months of pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before starting Prozac treatment. For details about Prozac’s use during pregnancy, see this article.
• Breastfeeding. Prozac can pass into breast milk, which may lead to side effects in a child who is breastfed. If you’re breastfeeding or considering it, talk with your doctor before taking Prozac. To learn more about Prozac’s use while breastfeeding, see this article.
• Allergic reaction. If you’ve had an allergic reaction to Prozac or any of its ingredients, your doctor will likely not prescribe Prozac. Taking the drug may cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

You can take certain steps to help prevent interactions with Prozac. 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 take 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 Prozac 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 Prozac 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 Prozac by taking it exactly as your doctor prescribes.

Besides learning about interactions, you may want to find out more about Prozac. These resources might help:

• Overview of Prozac. For a general overview of Prozac, you can see this article.
• Side effects. If you’re interested in the side effects of Prozac, see this article. Another option is to refer to the Prozac prescribing information.
• Drug comparison. For information about how Prozac compares with Zoloft, read this article.
• Facts about bipolar disorder and depression. To learn more about bipolar disorder and depression, see our bipolar disorder hub and depression hub.

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.