Can you overdose on antipsychotics?

Is it possible to overdose on antipsychotics?

It is possible to overdose on antipsychotics and is a matter of vital importance. Antipsychotic medications, like many other types of medications, have a therapeutic range in which they are effective and safe. Taking an excessive dose of antipsychotics can lead to serious health risks and complications.

Patients can develop cardiotoxicity, seizures, or coma, requiring an admission to an intensive care unit. ^[1] These outcomes are associated with severe overdoses, with many antipsychotic overdoses resulting in mild sedation and patients being discharged six hours after the initial poisoning. ^[1] Nonetheless, people have died due to overdosing on atypical antipsychotics. ^[2]

Atypical antipsychotics, such as clozapine, risperidone, olanzapine, quetiapine, and ziprasidone, were made available for use in the late 1980s. ^[2] Deaths resulting from atypical antipsychotic overdose are often related to cardiovascular complications, but can also be the result of gastrointestinal, neurological, or endocrine issues. ^[2]

Since the late 1980s, morbidity and mortality from antipsychotic overdose has increased, with a 2016 Australian study showing that these increases occurred despite overall drug overdoses falling. ^[3] Olanzapine and quetiapine accounted for 78% of these overdoses, whist atypical antipsychotics generally made up most overdoses. ^[4]

How do antipsychotics cause toxicity?

Antipsychotics cause toxicity in multiple ways including obstructing potassium and sodium channels in the body, via alpha-1 adrenergic blockade and through anticholinergic effects. ^[4] Various organs are impacted but the cardiovascular and central nervous system are affected worse than any others. ^[4]

What factors contribute to antipsychotic overdose?

Understanding the factors that contribute to antipsychotic overdose is crucial for preventing overdose and promoting safe medication use. Here are some key contributors to antipsychotic overdose:

• Dose and Medication Strength: Taking a higher dose of antipsychotic medication than prescribed significantly increases the risk of overdose. ^[2] Additionally, some formulations of antipsychotics may have higher concentrations, making them more potent.
• Accidental Ingestion: Accidental ingestion can occur when someone, especially children, mistakenly ingests antipsychotic medication that was not stored securely or was mistaken for another medication.
• Combining with Other Substances: Self-poisoning by mixing antipsychotic medications with alcohol, antidepressants, opioids, and other illicit drugs can potentiate the effects and increase the risk of overdose. ^[5]

Symptoms of antipsychotic overdose

Antipsychotic overdose can lead to a wide range of symptoms including: ^[6]

• Extreme sedation
• Agitation
• Delirium
• Hallucinations
• Coma
• Tachycardia
• Mydriasis
• Flushed Skin
• Decreased production of sweat
• Decreasedproduction of saliva
• Urinary retention
• Mild hypotension
• Nausea
• Vomiting
• Dystonia (involuntary muscle movements)

It's important to note that the symptoms of antipsychotic overdose can vary widely, and not everyone will experience the same set of symptoms. A person may suffer cardiovascular, neurological, pulmonary, endocrine, dermatologic, or metabolic symptoms relating to overdose. ^[6] Additionally, other factors such as the presence of other substances in the body can complicate the clinical presentation.

Treatment for antipsychotic overdose

The treatment for antipsychotic overdose involves swift medical intervention to stabilize the individual and address the effects of the overdose. It typically includes:

1. Assessment and Monitoring: Healthcare professionals assess the individual's vital signs, conduct a physical examination, and gather information about the overdose circumstances.
2. Supportive Care: Measures are taken to stabilize the person's condition, including providing oxygen, maintaining hydration, and managing blood pressure and heart rate. ^[1]
3. Activated Charcoal or Gastric Lavage: If the overdose occurred recently, activated charcoal might be administered to absorb the excess medication. ^[1] Gastric lavage (stomach pumping) could also be considered to remove the medication.
4. Medication Reversal: In some cases, antidotes or medications may be used to counteract the effects of the overdose, if available and appropriate.
5. Symptom Management: Healthcare professionals address specific symptoms such as sedation, abnormal heart rhythm, and respiratory insufficiency.  Patients may require intubation, hyperventilation,or plasma alkalinization. ^[1]
6. Monitoring: The individual's vital signs, mental status, and other parameters are continuously monitored to detect any changes and ensure stabilization.
7. Psychological Support: Individuals who have overdosed might require psychological support, from a counsellor or therapist, to manage any emotional distress or confusion.

The treatment approach depends on factors such as the type and amount of medication ingested, individual health status, and presence of other substances. Many antipsychotic overdoses will result in mild sedation, with patients allowed to leave hospital six hours after the initial poisoning. ^[1]

However, in serious cases, symptoms need to be managed effectively as quickly as possible. Seeking immediate medical attention is crucial in cases of antipsychotic overdose to prevent serious complications and ensure the person's well-being.