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Newer antipsychotic mechanisms matter because not every second-generation antipsychotic works the same way, some steady dopamine signalling rather than blocking it outright, and knowing which is which predicts side effects better than just knowing the drug is 'atypical'. Cariprazine and brexpiprazole are D2/D3 receptor (two dopamine receptor subtypes) partial agonistsA drug that activates a receptor but produces a smaller effect than a full agonist, even at a high dose.Read more →, sometimes called dopamine stabilisers because they dampen dopamine activity where it is too high and support it where it is too low. Lurasidone instead works as a D2 and 5-HT2AA serotonin receptor subtype that many antipsychotic drugs block, thought to help their antidepressant and antipsychotic effect.Read more → (a serotonin receptor subtype) antagonistA drug that blocks a receptor, stopping it from being activated.Read more →, with additional 5-HT7 antagonism. For example, imagine two patients started on cariprazine and lurasidone respectively: the cariprazine patient is less likely to develop raised prolactinA hormone, raised by some antipsychotic drugs, linked to milk production and periods stopping.Read more → (the milk-producing hormone) than a patient on a pure D2 antagonist, because partial agonism spares the pituitary gland's prolactin control.

Cariprazine and brexpiprazole partially activate D2 and D3 receptors rather than fully blocking them, which is why they are called dopamine stabilisers and why they spare prolactinA hormone, raised by some antipsychotic drugs, linked to milk production and periods stopping.Read more → compared with full D2 antagonistsA drug that blocks a receptor, stopping it from being activated.Read more →. Cariprazine has particularly high affinityHow strongly a drug binds to its receptor.Read more → for D3 receptors, a feature linked to potential benefit for negative symptoms (reduced motivation and social withdrawal) in schizophreniaA long-term mental illness involving episodes of psychosis such as hallucinations and delusions.Read more →, a psychotic illness with delusionsA fixed false belief, held with total conviction, that is not shared by the person's culture and is not changed by evidence against it.Read more → and with hallucinationsSeeing, hearing, or otherwise sensing things that are not really there.Read more → (false perceptions without a real stimulus). Lurasidone combines D2 and 5-HT2AA serotonin receptor subtype that many antipsychotic drugs block, thought to help their antidepressant and antipsychotic effect.Read more → antagonism with 5-HT7 antagonism, and has a comparatively favourable metabolic profile, less weight gain and fewer lipid changes than some other second-generation antipsychotics. For example, imagine a patient prescribed lurasidone who is told to take it with a substantial meal of at least 350 kilocalories: skipping this halves the amount absorbed. In practice, this means checking a patient's mealtime routine is as important as checking the dose when prescribing lurasidone.

• A woman with bipolar affective disorder is in a depressive episode. Which of the newer antipsychotics holds a specific licence for bipolar depression?
• A man stops cariprazine abruptly, and his clinician warns that drug effects will persist for some weeks. Which pharmacokinetic property explains this prolonged persistence?
• A young man with schizophreniaA long-term mental illness involving episodes of psychosis such as hallucinations and delusions.Read more → has gained substantial weight on olanzapine and needs a switch. Which newer agent is most often chosen for its favourable metabolic profile?
• A man with schizophreniaA long-term mental illness involving episodes of psychosis such as hallucinations and delusions.Read more → has prominent apathy, poverty of speech and social withdrawal rather than positive symptoms. Which newer agent has the strongest evidence for this symptom domain?

• Cariprazine/brexpiprazole, D2/D3 partial agonistsA drug that activates a receptor but produces a smaller effect than a full agonist, even at a high dose.Read more → (dopamine stabilisers) sparing prolactinA hormone, raised by some antipsychotic drugs, linked to milk production and periods stopping.Read more →, unlike full D2 antagonistsA drug that blocks a receptor, stopping it from being activated.Read more → such as risperidone which reliably raise prolactin.
• Lurasidone, D2/5-HT2AA serotonin receptor subtype that many antipsychotic drugs block, thought to help their antidepressant and antipsychotic effect.Read more → antagonistA drug that blocks a receptor, stopping it from being activated.Read more → with added 5-HT7 antagonism, rather than the partial-agonistA drug or chemical that activates a receptor to produce an effect.Read more → mechanism of cariprazine and brexpiprazole.
• Lurasidone food requirement, needs at least 350 kilocalories with the dose for full absorption, unlike most other oral antipsychotics which are food-independent.
• Aripiprazole, an older D2/D3 partial agonistA drug that activates a receptor but produces a smaller effect than a full agonist, even at a high dose.Read more → and the prototype dopamine stabiliser, whereas cariprazine has notably higher D3 affinityHow strongly a drug binds to its receptor.Read more →.

• That agent is not licensed for this indication here.
• That older agent is not licensed for bipolar depression.
• That agent's licensed indications differ in the United Kingdom.
• Skin excretion is not a meaningful elimination route here.
• An inactive stored compound would not prolong drug effect.

• Identify the drug, receptor, enzyme or pharmacokinetic change named in the stem.
• Translate it into the immediate mechanism before looking at the options.
• Use timing and the adverse-effect pattern to separate the nearest alternatives.
• Check whether the question asks for mechanism, clinical consequence, monitoring or management.