Atypical Antipsychotics
Atypical antipsychotics can be lifesaving for people who have schizophrenia, bipolar disorder or severe depression. But patients should think twice... before using these drugs to deal with... unhappiness, anxiety and insomnia - Richard A Friedman MD
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The rise and fall of the atypical antipsychotics
In creating successive new classes of antipsychotics over the years, the industry has helped develop a broader range of different drugs with different side-effect profiles and potencies, and possibly an increased chance of finding a drug to suit each of our patients. 4 But the price of doing this has been considerable – in 2003 the cost of antipsychotics in the USA equalled the cost of paying all their psychiatrists. The story of the atypicals and the SGAs is not the story of clinical discovery and progress; it is the story of fabricated classes, money and marketing
Resources
Are atypical antipsychotics advantageous? - the case for
Atypical antipsychotics are a diverse group of drugs. Their widespread use has significantly improved the treatment of schizophrenia. Most patients no longer experience extrapyramidal adverse effects from drugs, including the often irreversible tardive dyskinesia. However, serious adverse reactions can occur with atypical antipsychotics. While atypical antipsychotics have modest efficacy advantages over typical antipsychotics, the efficacy varies between drugs and from patient to patient.
Atypical Antipsychotic Medication Re-initiation in the Emergency Department
While the atypical antipsychotics have generally been considered safer than the first generation agents due to the decreased risk of extrapyramidal side effects at therapeutic doses, this class is not without adverse effects.
Atypical Antipsychotic Overdose: It's All About the Receptors
All the atypical antipsychotics block various neurotransmitter receptors. Understanding the nature of these receptors and the pharmacologic profile of commonly prescribed agents makes it possible to predict the manifestations one would expect to see in overdose. Antipsychotics bind to and block several receptors to a degree that varies from agent to agent.
Atypical antipsychotics: are they truly safer than typical antipsychotics?
The atypical (2nd generation) antipsychotics are considered to possess less toxicologic manifestation compared to the typical (1st generation) antipsychotics - lower K channel blockade and minimum Na channel blockade properties. However, select atypical antipsychotics overdose can results in significant morbidity in addition to sedation.
First versus second generation
Moderate to high quality evidence suggests a small effect of improved overall symptoms with second-generation antipsychotics, particularly olanzapine, amilsulpride, and risperidone, compared to first-generation antipsychotics, particularly high-dose haloperidol (>12mg/day), which is not as effective as lower doses.
How Do Atypical Antipsychotics Work for Depression?
In spite of the significant advances in medical treatment for depression, there are still many patients who fail to respond positively to the typical course of treatment. When clinicians are faced with a patient with depression who is resistant to other forms of treatment, they may recommend atypical antipsychotics.
Quetiapine toxicity
If you need to remember one number then >3 grams there is increasing risk of CNS depression, coma and hypotension. It is in fact like with all overdoses, a continuum and also depends on the patient’s tolerance.
Quetiapine versus other atypical antipsychotics for schizophrenia
Available evidence from trials suggests that most people who start quetiapine stop taking it within a few weeks (around 60%).
TIPS for Managing the Acutely Agitated Patient
The more recently developed second-generation (“atypical”) antipsychotics have more varied mechanisms of action. Of the SGA, olanzapine (Zyprexa), risperidone (Risperdal), and ziprasidone (Geodon) are the most frequently used in the management of acute agitation. Olanzapine can be given IM or PO. Off-label, it has been used via IV route, but carries an increased risk of respiratory depression. But even IM olanzapine should not be used in combination with a benzodiazepine due to increased risk of respiratory depression, excessive sedation, and hypoxia. Although used less frequently, risperidone and ziprasidone can also be given PO or IM.
Use of Atypical Antipsychotic Drugs in Patients with Dementia
Current guidelines recommend using risperidone and olanzapine to treat psychosis in patients with Alzheimer's dementia. Quetiapine and clozapine are recommended for treatment of psychosis in patients with Parkinson's disease. Additional research is needed for a recently approved agent, ziprasidone.
The rise and fall of the atypical antipsychotics
The antipsychotics brought hope and optimism to people with schizophrenia and to those who care for them. There have been successive classes of antipsychotics used by the pharmaceutical industry to persuade doctors and patients that ‘new’ is better. Evidence is growing that the primary purpose of these fabricated classes is for marketing. It is time we stopped using these expensive labels – they are all just antipsychotics.
Overdose
Treatment of atypical antipsychotic overdose is mainly supportive. Activated charcoal may be considered if administered within an hour of ingestion, as long as no contraindications exist, such as the presence of sedation or vomiting. Treatment of antimuscarinic effects is generally symptomatic. The most life-threatening issue with this toxicity is often the agitated behavior of the patient. Although these individuals are not usually violent as are those exhibiting sympathomimetic toxicity, they can hallucinate and may need physical or chemical restraint. Physostigmine, a carbamate-type cholinesterase inhibitor can also be used in the management of antimuscarinic delirium. Small doses of 1–2 mg administered intravenously can usually reverse the delirium, and patients often will not be as agitated after the pharmacologic effects of physostigmine wear off in 30–60 min. If NMS is suspected, the most important aspect of treatment is withdrawal of the offending agent and particular attention to fluid and electrolyte balance.
StatPearls
In recent years, atypical antipsychotics or second-generation antipsychotics have become the drugs of choice for acute psychoses. They are “atypical” as they are differentiated from “conventional” or first-generation antipsychotics based on their clinical profile.
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