Can You Overdose on Antidepressants?

Is It Possible to Overdose on Antidepressants?

An antidepressant overdose happens when a larger-than-normal dose of an antidepressant is ingested. It can also happen from taking large doses of more than one antidepressant at the same time. There is not one set dose that defines an overdose. The dose that causes an overdose differs from person to person. It is based on a person’s bodily characteristics, the current dose and time on an antidepressant, and the antidepressant medication itself.

Overdoses are also based on a person’s medical history and pre-existing health conditions. An overdose can occur intentionally by a person deliberately taking many pills at one time. An overdose can occur unintentionally by taking more than one antidepressant at a time, changing doses too quickly, or inadvertently doubling up on doses. It is important to keep medication in a safe place and always follow prescription directions to reduce the risks of overdose.

What To Do if You Suspect an Antidepressant Overdose

If you suspect you or someone you know is experiencing an antidepressant overdose, you should get help right away. Call 911 immediately and stay with the person experiencing the overdose. If you are experiencing an overdose, have someone call on your behalf and stay with you until help arrives.

In addition, poison control may be good to call at 800-222-1222. If you are unsure of an overdose, still call 911 immediately as symptoms can drastically change for the worse in a short amount of time.

Signs & Symptoms of Antidepressant Overdose

Antidepressant overdose can look different from person to person and based on the severity of the overdose. Symptoms range from sweating and dizziness to cardiac irregularities, seizures, and coma.

A large factor is the type of medication that causes the overdose. Reviewing the specific signs of an overdose of your specific medication with your doctor or pharmacist is very important. This can help you recognize symptoms of an overdose and get help quickly.¹

Mild symptoms of an antidepressant overdose may include:

• Rapid or irregular heart rate
• Nausea
• Lethargy
• Diarrhea
• Confusion
• Dizziness
• Fever or chills
• Headache
• Slurred speech
• Blurred vision

Severe symptoms of antidepressant overdose may include:

• Seizures
• Cardiac arrest
• Coma
• Respiratory depression or arrest
• Fainting
• Renal failure
• Acidosis

Prescribed & Lethal Doses of Antidepressants

Typically prescribed doses of antidepressants vary among drugs and drug classes. There are chemical factors and bodily factors that determine appropriate doses for each medication. These doses have been studied at length and are understood to be generally safe for treatment. While some people may take higher than normal doses the majority of people will take the medication with doses in the typical dose range.

The dangerous dose of antidepressants can be slightly higher or much higher than typical doses. This also depends on the medication and each person’s specific health history and body characteristics. A lethal dose (LD50) is generally accepted to be the dose at which half of the exposed population dies from the dose.

The lethal dosage amount of an antidepressant depends on many factors, including:

• The type of antidepressant
• Your age
• Length of time you have been taking the antidepressant
• Other medications you currently take
• Body weight and body makeup

Below are the typically prescribed dosages for each class of antidepressants:

Selective Serotonin Reuptake Inhibitors (SSRIs)

SSRIs are one of the newer medications used to treat depression and anxiety. They are very common as they are the first-line treatment for both conditions. They work to increase the amount of active serotonin working in the body. Of the medications used as antidepressants, they are safer and have fewer fatal outcomes after an overdose.¹

Here is dosage information on commonly prescribed SSRIs:²

Generic name	Brand name Typical dosage range
Citalopram	Celexa* 10mg - 40mg
Sertraline	Zoloft* 25mg - 100mg
Escitalopram	Lexapro* 5mg - 20mg
Fluoxetine	Prozac* 10mg - 40mg
Paroxetine	Paxil* 20mg - 50mg

*Medications within the SSRI drug class have a black box warning. These are the most serious type of warnings from the Food and Drug Administration (FDA). SSRIs can increase the risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Regardless of age, you should talk with your doctor about severe risks with SSRIs before starting treatment.  

Most SSRIs are well tolerated and have relatively lower risks of overdose than other antidepressants mentioned in this article. The most common side effects experienced in SSRI overdoses are relatively benign gastrointestinal and neurological side effects.¹ Citalopram is by far the most relatively toxic of the SSRIs and is more likely to cause cardiac-related side effects and seizures.

The risk of fatal overdose from SSRIs increases if a person is also taking medications that also increase serotonin in the body. Examples of these medications include other antidepressants and opiates.^{3, 4}

Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)

SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors) are also one of the newer medications used to treat depression and anxiety. They are less commonly prescribed than SSRIs but more commonly prescribed than most TCAs and MAOIs. They work to increase the amount of active serotonin and norepinephrine working in the body. Of the medications used as antidepressants, they are safer and have fewer fatal outcomes after an overdose. ¹

Here is dosage information on commonly prescribed SNRIs:

Generic name	Brand name Typical dosage range
Desvenlafaxine	Pristiq* 25mg - 100mg
Duloxetine	Cymbalta* 20mg - 60mg
Levomilnacipran	Fetzima* 40mg - 120mg
Venlafaxine	Effexor XR* 37.5mg - 150mg

*Medications within the SNRI drug class have a black box warning. These are the most serious type of warnings from the Food and Drug Administration (FDA). SNRIs can increase the risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Regardless of age, you should talk with your doctor about severe risks with SNRIs before starting treatment. 

SNRIs have less risk for fatal overdoses than most other antidepressants but have more risk than most SSRI medications.³ The most common overdose symptoms are limited to nausea, vomiting, and drowsiness.¹ The risk for potentially fatal overdoses increases greatly when taken with other medications, especially MAOIs, opiates, and lithium.⁴

Tricyclic & Tetracyclic Antidepressants (TCAs)

Tricyclic and tetracyclic antidepressants, or TCAs, are one of the older antidepressant medication classes and are less commonly prescribed than other medications. TCAs work in the central nervous system to inhibit presynaptic reuptake of norepinephrine and serotonin.

TCAs are used to treat depression but they aren’t first-line treatments, and other conditions like migraines, OCD, and certain pain disorders. ⁵ TCA medications have a higher risk of fatal overdose than other antidepressants.⁶

Here is dosage information on commonly prescribed TCAs:

Generic name	Brand name Typical dosage range
Amitriptyline	Elaval* 10mg - 100mg
Amoxapine	Asendin* 150mg - 300mg
Desipramine	Norpramin* 50mg - 200mg
Doxepin	Silenor* 3mg - 6mg
Imipramine	Tofranil* 50mg - 150mg
Nortriptyline	Pamelor* 25mg - 100mg
Protriptyline	Vivactil* 5mg - 10mg
Trimipramine	Surmontil* 25mg - 50mg

*Medications within the TCA drug class have a black box warning. These are the most serious type of warnings from the Food and Drug Administration (FDA). TCAs can increase the risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Regardless of age, you should talk with your doctor about severe risks with TCAs before starting treatment.  

Overdoses from TCAs carry a significant risk for serious antidepressant side effects. They are much more likely than other antidepressants to cause dangerous side effects like seizures, coma, cardiovascular effects, and renal toxicity.¹ The risk of fatal overdose varies from person to person based on body makeup and metabolism.⁵ Other medications like opiates and other antidepressants can increase the risk of fatal overdose.⁴

Monoamine Oxidase Inhibitors (MAOIs)

MAOIs have also declined in use with the development of other, safer, options. They work in the nervous system to inhibit the activity of monoamine oxidase, which metabolizes serotonin. They are usually used to treat depression that is atypical or difficult to treat, as well as panic disorder and social anxiety.⁷

Here is dosage information on commonly prescribed MAOIs:

Generic name	Brand name Typical dosage range
Isocarboxazid	Marplan* 10mg - 40mg
Phenelzine	Nardil* 15mg - 30mg
Selegiline	Emsam* 5mg - 10mg
Tranylcypromine	Parnate* 15mg - 30mg

*Medications within the MAOI drug class have a black box warning. These are the most serious type of warnings from the Food and Drug Administration (FDA). MAOIs can increase the risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Regardless of age, you should talk with your doctor about severe risks with MAOIs before starting treatment.  

MAOIs cause serious symptoms and complications in an overdose. The risk is high as the dose needed to cause an overdose is relatively low. Symptoms include cardiac effects, hypertension, hypotension, and hyperthermia.¹ MAOIs also pose a greater risk for overdose because there are many common foods and medications that interact with them. Common foods include beer, cheese, wine, and sauerkraut. Common medications include SSRIs, SNRIs, and pain medications like tramadol.⁷

Health Impacts of Antidepressant Overdose

Antidepressant overdoses pose serious health risks both in the short and long term. Immediate risks of overdose include serious side effects like seizure and changes in heart function that can lead to death if untreated. There is also a serious risk of developing a life-threatening condition called serotonin syndrome. This occurs when the body is overloaded with serotonin from multiple medications or very high doses in a short amount of time. This condition can cause extreme fever, increased heart rate and blood pressure, and coma.⁴

Treatment for an Antidepressant Overdose

Recognizing and treating an antidepressant overdose immediately is key to reducing harmful effects and preventing death. Calling 911 is the first step to ensure prompt care. Treatment of an antidepressant overdose will vary depending on each person, the type of antidepressant, and the overdose symptoms. It is important to gather and share as much information as possible to aid in effective overdose treatment.

When seeking treatment for an antidepressant overdose, be sure to share your:

• Current signs and symptoms
• Regular dosage amount
• Estimated amount of medication ingested
• Other medications taken within the past 24 hours
• Alcohol or recreational drugs taken recently
• Significant health history (seizures or heart problems)

Emergency Antidepressant Overdose Treatment

Treatment for antidepressant overdoses will vary from person to person. Generally, the objective is to remove or neutralize the antidepressant, stabilize the patient, and monitor for new symptoms that may occur. The most severe and life-threatening side effects present within 24 hours and therefore prompt treatment is crucial. Calling 911 will help determine the severity of the overdose. When in doubt seek immediate treatment at the emergency room.

Most treatments for an overdose last a few days to ensure the patient is stable and the antidepressant causing the overdose is eliminated from the body. However, if the overdose was intentional, further care will be recommended to safely restart an antidepressant. If the overdose causes serious health impacts, a long treatment may be required to treat secondary conditions.^{5, 7}

Emergency treatment for an overdose on antidepressants may include:

• Treating cardiac conditions and acidosis with IV sodium bicarbonate
• Managing fever with medication or ice baths in severe overdoses
• Treatment of seizures with benzodiazepines
• Watching vital signs closely and treating any dangerous changes that occur
• Activated charcoal may be used if ingestion of the medication was very recent
• Treatment with IV intralipids
• Treatment with oral cyproheptadine

Next Steps After an Antidepressant Overdose

In the time after an overdose, it is crucial to take steps to prevent further overdoses and continue proper treatment. It is important to follow up based on whether the overdose was intentional or not. If the overdose was intentional, additional mental health treatment will be recommended. If the overdose was accidental, evaluation of the current medication dosage and directions is expected. Either way, communication with your healthcare team is most important. Specific steps should be taken and additional support should be provided to prevent the risk of future overdose.

If the Overdose on Antidepressants was Unintentional

If the overdose was unintentional you and your prescriber should work together to review in detail your medication. Your specific dose may need to be altered or increased at a slower rate. Additionally, you should review how you take the medication and what happens if you miss a dose. Finally, you should review all of your current medications to determine if an interaction is putting you at higher risk of future overdose.

Next steps to consider after an unintentional antidepressant overdose include:

• Take your medication exactly as prescribed. Do not double up on missed doses or change the time you take your medication.
• Consult your psychiatrist regarding your dosage and medication interactions to prevent accidental overdose again.
• Discuss switching to a safer antidepressant. Different antidepressants have higher or lower risks of overdose.
• Avoid other substances that may increase risk of overdose. Depending on the antidepressant you take, foods and medications can increase risk of overdose.

H3: If the Overdose on Antidepressants was Intentional

If the overdose was intentional, the steps to prevent future overdoses look slightly different. It is important to utilize the help of a proper support system. This can include additional recovery therapy, storing your medication with someone you trust, and more frequent check-ins with your therapist. Reducing access to methods of self-harm is one step. Additionally, the increased risk of self-harm in young people taking antidepressants is important to address.

Next steps to consider after an intentional antidepressant overdose include:

• Store your medication in a safe place or with someone you trust, so you only have access to the proper dose each time.
• Seek out and regularly attend psychotherapy. This is an important step in handling symptoms that may trigger harmful thoughts and self-harm behaviors.
• Work with your prescriber to ensure your antidepressant is the right fit for you. Potentially a change in medication can reduce the risk of overdose in the future.
• Avoid other substances that alter your mental status or make the risk of overdose higher.

In My Experience

Antidepressant overdose is a serious risk that comes with taking antidepressant medication. Understanding how it can happen, what increases your risk, and what to do if it occurs are all important parts of treatment with antidepressants. If you or someone you know may be experiencing an antidepressant overdose, immediate treatment is the most important

step to reducing harm. Always ask your healthcare provider any questions you may have about your medication and communicate uncertainties to reduce the risk of antidepressant overdose.