Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 6/22/2022
If you’ve been diagnosed with major depressive disorder (MDD), obsessive-compulsive disorder (OCD), panic disorder (PD) or an eating disorder such as bulimia, your healthcare provider may prescribe the antidepressant Prozac®.
Prozac, which contains the active ingredient fluoxetine, is generally safe and effective when used as prescribed. However, it is possible to overdose on Prozac. Although rare, an overdose of Prozac may even be deadly.
We’ve also shared the symptoms you could experience if you take too much Prozac, as well as what you can do to seek help and keep yourself safe.
Prozac is an antidepressant that belongs to a class of drugs called selective serotonin reuptake inhibitors, or SSRIs. It works by increasing the amount of serotonin — a type of natural chemical called a neurotransmitter — that’s active in your brain and body.
Serotonin is one of several neurotransmitters that’s involved in regulating the way you think, feel and behave. It’s involved in managing your moods, happiness and feelings of anxiety, as well as certain aspects of your sleep cycle and physical health.
Normal levels of serotonin are associated with emotional stability and mental focus. People with low levels of serotonin may be more likely to develop certain mental health conditions, including depression, anxiety and obsessive-compulsive disorder.
By increasing serotonin levels, Prozac and similar medications can help to lower the severity of depression and anxiety symptoms, improving your mood and quality of life.
Prozac is available as a capsule, a tablet and as a liquid solution. It’s also available in capsule form as an extended-release medication. Like other antidepressants, Prozac is available as a brand-name drug and in generic form as fluoxetine.
The normal dosage for Prozac ranges from 10mg per day to 80mg per day. Prozac and generic fluoxetine should not be used at a dosage exceeding 80mg per day.
Your healthcare provider will determine the optimal dosage of Prozac for you based on a range of factors, including your age, body weight, overall health, symptoms and whether or not you’re currently using any other medications.
It’s important not to adjust your dosage of Prozac or stop taking your medication without talking to your healthcare provider.
Prozac was approved by the FDA in 1987 as one of the first SSRIs to come onto the market as a treatment for depression. Today, SSRIs such as Prozac are thought of as first-line treatments for depression due to their efficacy and improved safety over older antidepressants.
Although Prozac has fewer safety issues than older antidepressants and is less likely to cause interactions, it’s still possible to overdose on Prozac.
You may be at risk of overdosing on Prozac if you:
Deliberately take more than your prescribed dose of Prozac
Accidentally take Prozac more than once, or at an overly high dosage
Combine Prozac with certain medications or dietary supplements
Taking an overly large dose of Prozac could increase your risk of experiencing side effects from this medication. Common side effects of Prozac include:
Feelings of anxiety
Loss of appetite
Prozac can also cause sexual side effects, including a low sex drive and anorgasmia (difficulty reaching orgasm). In men, Prozac may cause sexual issues such as difficulty ejaculating and erectile dysfunction.
In addition to increasing your risk of developing side effects from Prozac, overdosing may lead to the development of a serious drug reaction called serotonin syndrome.
Serotonin syndrome is a potentially life-threatening condition that can develop when your levels of serotonin become excessively high. It can cause a variety of symptoms and range in severity from mild to extremely serious.
When mild, serotonin syndrome may involve elevated blood pressure, tachycardia (a heart rate of 100 beats per minute or faster), shivering, tremor, dilated pupils, excessive sweating, muscle jerking and overly responsive reflexes.
More severe serotonin syndrome may involve hyperthermia, agitation, irregular eye movements, hypervigilance, pressured speech and hyperactive bowel sounds.
Severe serotonin syndrome can involve a significantly elevated temperature of 106°F or higher, as well as dramatic changes in blood pressure, heart rate, muscle rigidity and mental state. In very severe cases, serotonin syndrome can potentially cause seizures, coma and death.
Your risk of serotonin syndrome is higher if you combine Prozac with other drugs and/or dietary supplements that can increase serotonin levels.
These include other antidepressants, such as other SSRIs, tricyclic antidepressants (TCAs) or monoamine oxidase inhibitors (MAOIs).
Other SSRIs include:
Common monoamine oxidase inhibitor medications include:
Some MAOIs may stay in your body for approximately two weeks after your last dose. Make sure to tell your healthcare provider if you currently use or have recently used any monoamine oxidase inhibitors to treat depression or related conditions.
Common tricyclic antidepressants include:
Other medications that increase can serotonin levels and contribute to a higher risk of overdose symptoms include:
Mood stabilizers, such as lithium
Opioid painkillers, such as tramadol and fentanyl
Medications for migraines and headaches, such as triptans
Some dietary supplements, such as St. John’s wort, can increase serotonin levels and cause an elevated risk of serotonin syndrome. Make sure to let your healthcare provider know about any supplements you currently use or have recently used before taking Prozac.
If you’ve taken more Prozac than prescribed, it’s important to seek medical help as soon as you can. It’s especially important to seek emergency medical help if you’re starting to develop one or several symptoms of serotonin syndrome.
You can get urgent assistance by calling your local emergency services at 911, or by contacting Poison Control at 1-800-222-1222. Poison Control also has an online contact form that you can use to seek help from your computer or mobile device.
Try to have the following information on hand when you call for help:
Your age (or the person’s age, if you’re calling for someone else)
Your sex, body weight and prescribed dosage of Prozac
The amount of Prozac or generic fluoxetine you consumed
Any other medications or other substances you’ve recently used
How long ago you took the Prozac or generic fluoxetine
If you have any medical conditions or health needs
Prozac is a common antidepressant that’s used to treat major depressive disorder, panic attacks and even eating disorders such as bulimia nervosa.
Can you overdose on Prozac? While it’s not common, it is possible to overdose on Prozac if you take an excessive amount of Prozac, or combine Prozac with other medications or supplements that increase your serotonin levels.
To keep yourself safe while using Prozac, let your healthcare provider know about any drugs or supplements you currently use or have recently used before starting treatment. If you have any adverse effects while using Prozac, make sure to inform them as soon as possible.
Finally, make sure to seek medical attention as soon as possible if you develop any symptoms of serotonin syndrome.
Interested in treating depression? We offer a complete range of mental health services online, including the ability to connect with a licensed psychiatry provider and access medications for depression and anxiety.
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