Antipsychotics Mnemonics (Memorable Psychopharmacology Lecture 4)

Summary

This script delves into antipsychotic medications, crucial for treating schizophrenia and other psychotic disorders. It distinguishes between first-generation 'typical' and second-generation 'atypical' antipsychotics, highlighting the former's higher risk of motor side effects due to dopamine receptor blockage, and the latter's metabolic issues like obesity and diabetes. The summary also touches on the importance of dopamine receptor subtype D2 in their mechanism, the wide range of side effects, and the significance of patient compliance in treatment efficacy.

Takeaways

• 💊 Antipsychotics are medications primarily used for treating schizophrenia and other psychotic disorders, divided into first-generation (typical) and second-generation (atypical) categories.
• 🧠 First-generation antipsychotics block dopamine receptors more aggressively, leading to motor and neurologic side effects, while atypicals have less affinity for the dopamine receptor but can cause metabolic issues like obesity and diabetes.
• 📉 Antipsychotics' efficacy and side effects are largely due to their modulation of dopamine, highlighting the neurotransmitter's role in various cognitive and motor functions.
• 🔑 A high-yield tip for remembering antipsychotics' mechanism is that they work on the dopamine receptor subtype D2, with 'D2R' sounding like 'dour', relating to taking a 'dour' from reality.
• 🚫 Despite their effectiveness, antipsychotics come with a wide array of side effects, emphasizing the importance of considering the third rule of neurotransmission: with great power comes great responsibility.
• 🚶‍♂️ Antipsychotics can induce Parkinson's disease-like symptoms, as they effectively create a form of medically induced Parkinson's with motor and cognitive effects.
• 🤐 Extrapyramidal side effects (EPS) are motor effects outside the medullary pyramids and include acute dystonia, akathisia, and akinesia, which can be remembered as 'muscle rustle and hustle'.
• 👄 Tardive dyskinesia is a serious, potentially irreversible side effect of long-term use of first-generation antipsychotics, characterized by involuntary rhythmic movements of the perioral muscles.
• 🌡 Neuroleptic malignant syndrome (NMS) is a life-threatening outcome of antipsychotic use, presenting with symptoms like severe confusion, agitation, and high fever, with a significant mortality rate.
• 🍼 Hyperprolactinemia is another side effect of antipsychotics, particularly risperidone, causing hormonal imbalances like breast enlargement in males due to dopamine's role in inhibiting prolactin.
• 📦 Antipsychotics are available in various dosage forms, including oral, dissolvable, intravenous, and intramuscular, with depot forms providing long-term control but requiring caution due to their irreversible nature once administered.

Q & A

What are the two main categories of antipsychotic medications?

The two main categories of antipsychotic medications are first-generation or typical antipsychotics and second-generation or atypical antipsychotics.

What is the primary difference between typical and atypical antipsychotics?

Typical antipsychotics work primarily by blocking dopamine receptors, which can lead to more motor and neurologic side effects, while atypical antipsychotics have less affinity for the dopamine receptor and can cause serious metabolic issues such as obesity, diabetes, and hyperlipidemia.

Why are antipsychotics sometimes referred to as 'medically induced Parkinson's disease'?

Antipsychotics can induce features of Parkinson's disease because they block dopamine, leading to motor and cognitive effects similar to those seen in Parkinson's, such as the 'Thorazine shuffle'.

What is the significance of the dopamine receptor subtype D2 in the context of antipsychotics?

The D2 receptor is significant because antipsychotics work on this receptor subtype. However, it's controversial as second-generation antipsychotics have relatively little activity at the D2 receptor.

What are the three main types of extrapyramidal side effects associated with antipsychotic medications?

The three main types of extrapyramidal side effects are acute dystonia, akathisia, and akinesia.

What is tardive dyskinesia and why is it a concern with long-term antipsychotic use?

Tardive dyskinesia is a condition characterized by involuntary, repetitive movements, often involving the face and tongue. It is a concern because it can be irreversible and affect a patient's quality of life negatively.

What is neuroleptic malignant syndrome and why is it considered serious?

Neuroleptic malignant syndrome is a life-threatening condition associated with antipsychotic use, characterized by fever, muscle rigidity, altered mental status, and autonomic dysfunction. It has a high mortality rate and requires immediate treatment.

Why is clozapine considered the most effective antipsychotic but not a first-line treatment?

Clozapine is considered the most effective antipsychotic due to its high efficacy rate, but it is not a first-line treatment because of the risk of agranulocytosis, a potentially deadly side effect where white blood cells are depleted.

How do atypical antipsychotics differ from typical antipsychotics in terms of side effects?

Atypical antipsychotics have fewer neurologic side effects like extrapyramidal symptoms (EPS) compared to typical antipsychotics but have a higher risk of metabolic and endocrine side effects, such as weight gain, diabetes, and hyperlipidemia.

What is the unique mechanism of action of aripiprazole (Abilify) and how does it differ from other antipsychotics?

Aripiprazole is unique because it acts as a partial agonist for both dopamine and serotonin receptors, rather than completely blocking them. This dual mechanism can be helpful for maintenance therapy and is sometimes used to augment antidepressant treatment.

Why is patient compliance important when considering the dosage forms of antipsychotics?

Patient compliance is crucial because without it, the effectiveness of antipsychotic treatment is greatly reduced. Different dosage forms, such as dissolvable, intravenous, or depot injections, can help ensure medication adherence, especially for patients who may not take medications regularly.