What Is A Lethal Dose Of Seroquel?

Medically Reviewed by Johnelle Smith, M.D. on August 1, 2023

Seroquel is an atypical antipsychotic medication that can be lethal in very high doses, or when mixed with other drugs. Adverse side effects of Seroquel toxicity include kidney failure, hyperglycemia, diabetic coma, and death.

What Is The Lethal Dose Of Seroquel?

Seroquel, the brand name for quetiapine, is an atypical antipsychotic drug that can have toxic effects if taken in very high doses alone or in combination with other drugs.

The standard dosage of Seroquel is 400 mg to 800 mg a day. Taking a higher amount of Seroquel may risk adverse side effects, including hyperglycemia, kidney damage, and death.

Learn more about the lethal dose of commonly abused drugs.

Understanding The Lethal Dose Of Seroquel

Research on the safety of Seroquel shows that the lowest reported dose associated with fatality occurred after a person took 6,000 milligrams—or 7.5 times the maximum recommended dose.

However, additional case reports have shown patient survival after the ingestion of up to 30,000 milligrams. In a clinical trial, one death was reported after a person took 13,600 mg.

Cause Of Seroquel Overdose

Seroquel overdose can be caused by taking an excessive amount of Seroquel alone, or in combination with other drugs.

One case series studying overdose incidents over five years identified the ingestion of high doses of Seroquel with opiates, amphetamines, benzodiazepines, cannabis, and barbiturates.

Factors That Can Affect The Lethal Dose

Certain factors may affect the risk of fatal overdose after taking a very high dose of Seroquel.

Risk factors for serious Seroquel overdose include:

  • older age
  • cardiovascular disease
  • impaired kidney or liver function
  • slow drug metabolism
  • low body weight
  • use of multiple drugs

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How Common Is Seroquel Overdose?

According to the Centers for Disease Control and Prevention (CDC), Seroquel is one of the most common drugs associated with suicide by drug overdose, along with prescription opioids and Xanax.

In 2016, Seroquel was involved in nearly 300 suicides by drug overdose. Seroquel overdose may be more common in people who have untreated or undertreated mental health disorders.

What Are The Signs Of Seroquel Overdose?

Severe cases of Seroquel overdose can be deadly. With prompt medical treatment, recovering from a Seroquel overdose is possible.

Signs and symptoms of Seroquel overdose include:

  • drowsiness
  • dizziness
  • rapid heartbeat
  • fainting
  • low blood pressure
  • coma

In rare cases, overdose may also lead to respiratory depression (slow or stopped breathing) and seizures. If someone is unresponsive or has collapsed after taking Seroquel, call 911 right away.

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Medically Reviewed by
Johnelle Smith, M.D. on August 1, 2023


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