Schizophrenia Pharmacology Review

A set of vocabulary-style flashcards covering the pharmacological classifications, receptor affinities, and mechanisms of action for antipsychotic medications used in treating schizophrenia.

Chlorpromazine (Largactyl)

The first antipsychotic drug, developed during the search for new antihistaminic drugs based on the hypothesis that histamine release causes shock.

First Generation Antipsychotics (FGA)

A class of medications (including Haloperidol and Fluphenazine) with very high affinity for $D_2/D_3$ receptors and lower affinity for $D_1$ receptors.

Clozapine

A Second Generation Antipsychotic that is highly efficient but carries a risk of agranulocytosis and requires monitoring for Benign Ethnic Neutropenia (BEN) in patients of African origin.

Agranulocytosis

A condition characterized by dangerously low levels of white blood cells (WBC), which is a potential side effect of Clozapine requiring regular monitoring.

Second Generation Antipsychotics (SGA)

Medications with moderate affinity for $D_2/D_3$ receptors and very high affinity for serotonin $5\text{-HT}_{2A}$, known for cause fewer motor side effects but more significant metabolic effects.

Amisulpride

A drug that behaves as an SGA with very high affinity for $D_2/D_3$ receptors and potential moderate beneficial effects on negative symptoms.

Affinity

The concentration of a drug that is necessary to occupy half of all the present receptors.

$$pKi$$

The inverse $\text{log}_{10}$ of the concentration of the drug necessary to displace half of a selective ligand; a higher value indicates higher affinity (e.g., $9-12$ is high affinity).

Third Generation Antipsychotics (TGA)

Antipsychotics similar to SGA that act as partial agonists at $D_2/D_3$ receptors and may boost dopamine in the frontal areas through $5\text{-HT}_{1A}$ agonism.

Partial Agonist Action (Mesolimbic)

In a hyper-dopaminergic state, these compete with dopamine to attenuate neurotransmission, which helps treat positive symptoms.

Partial Agonist Action (Mesocortical)

In a hypo-dopaminergic state, these bind to unoccupied receptors to generate an intracellular signal and boost dopamine neurotransmission, improving cognitive and negative symptoms.

TGA Medications

A group of drugs including Aripiprazole, Bifeprunox, Brexpiprazole, and Cariprazine that show efficiency for positive symptoms with low motor and metabolic effects.