Serotonin Syndrome vs NMS & Antidepressant Actions

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Questions and Answers

What is the recommended treatment for serotonin syndrome?

Benztropine

Cyproheptadine (correct)

Sertraline

Fluoxetine

Which agent should be used cautiously in patients concerned about weight gain?

Mirtazapine (correct)

Fluoxetine

Sertraline

Vilazodone

Which symptom is primarily associated with akathisia?

Involuntary muscle movements

Sustained muscle contraction

Tremors and rigidity

Restlessness and inability to sit still (correct)

What is the effect of SSRIs on brain-derived neurotrophic factor (BDNF) levels?

SSRIs increase BDNF levels Signup and view all the answers

In what circumstance is sertraline recommended?

In cases of depression during pregnancy Signup and view all the answers

Which of the following is a common side effect of antipsychotics due to D2 blockade in the nigrostriatal pathway?

Acute dystonia Signup and view all the answers

Which of the following conditions is particularly linked to the long-term use of first-generation antipsychotics (FGAs)?

Tardive dyskinesia Signup and view all the answers

What is the mechanism of action of vilazodone?

It behaves as a partial agonist at the 5-HT1A receptors Signup and view all the answers

What is one potential method to manage hyperprolactinemia caused by antipsychotics?

Add aripiprazole to the treatment plan. Signup and view all the answers

Which medication combination is stated to enhance efficacy in treating depression?

Mirtazepine + SNRI Signup and view all the answers

Which medication requires an oral trial before administration of its long-acting injectable form?

Invega Trinza Signup and view all the answers

Which SSRI is associated with a higher incidence of sexual side effects?

Paroxetine Signup and view all the answers

What is the recommended waiting period before switching from an MAOI to an SSRI?

2 weeks Signup and view all the answers

What is a common consequence of blocking M1 muscarinic receptors?

Blurred vision Signup and view all the answers

Which antipsychotic is associated with the highest risk of extrapyramidal symptoms (EPS)?

Fluphenazine Signup and view all the answers

Which of the following is NOT true about scoring in the AIMS examination?

Activated movements should be scored lower than other movements. Signup and view all the answers

What is the primary action of VMAT2 inhibitors like Valbenazine?

Decrease dopamine levels Signup and view all the answers

Which antidepressant combination mimics the effects of vilazodone?

Lexapro + Buspar Signup and view all the answers

What is the principal cause of orthostatic hypotension in patients taking iloperidone?

Blockade of alpha 1 adrenergic receptors Signup and view all the answers

Which receptor blockade is responsible for sedation and weight gain in antipsychotic medication?

H1-histaminic receptors Signup and view all the answers

When transitioning from an SSRI to an MAOI, what is the minimum waiting period recommended?

1 week Signup and view all the answers

Which antipsychotic medication is known for its sedative effects and higher anticholinergic side effects?

Chlorpromazine Signup and view all the answers

Which two antipsychotics are known to cause the most weight gain and metabolic dysfunction?

Clozapine and Olanzapine Signup and view all the answers

What cognitive impairments are commonly seen in schizophrenia due to acetylcholine downregulation?

Difficulties with executive functioning, attention, and memory Signup and view all the answers

Which dopamine pathway is primarily involved in regulating movement?

Nigrostriatal pathway Signup and view all the answers

What is the primary effect of too much dopamine in the mesolimbic pathway?

Positive symptoms of psychosis Signup and view all the answers

What condition is indicated by increased levels of prolactin due to insufficient dopamine?

Hyperprolactinemia Signup and view all the answers

Which symptom is NOT associated with neuroleptic malignant syndrome?

Mydriasis Signup and view all the answers

What is the first step in treating neuroleptic malignant syndrome?

Discontinuing the causative medication Signup and view all the answers

Which of the following abnormalities is commonly observed in patients suffering from neuroleptic malignant syndrome?

Elevated creatine kinase Signup and view all the answers

What is a key difference between neuroleptic malignant syndrome and serotonin syndrome?

Severity of hyperthermia Signup and view all the answers

What is the term used to describe the rigidity of muscles observed in neuroleptic malignant syndrome?

Lead-pipe rigidity Signup and view all the answers

Which antipsychotic is known for causing agranulocytosis and requires monitoring via the REMS registry?

Clozapine Signup and view all the answers

What class of medication does Aripiprazole belong to?

D2 partial agonist Signup and view all the answers

Which of the following antipsychotics is most likely to cause hyperprolactinemia?

Risperidone Signup and view all the answers

Which medication is considered the least sedating among the listed antipsychotics?

Ziprasidone Signup and view all the answers

What is a notable side effect of Olanzapine?

Sedation and weight gain Signup and view all the answers

Which antipsychotic is noted for being approved for agitation in Alzheimer's patients?

Brexpiprazole Signup and view all the answers

What differentiates 1st generation antipsychotics (FGAs) from 2nd generation antipsychotics (SGAs) in terms of receptor blocking?

SGAs also block 5HT2A receptors Signup and view all the answers

Which antipsychotic should be administered sublingually and is effective for patients who may chew their medication?

Asenapine Signup and view all the answers

Study Notes

Serotonin Syndrome and NMS Differentiation

To differentiate between serotonin syndrome and neuroleptic malignant syndrome (NMS), assess patient's current medications.
If the patient is taking medications that increase serotonin levels, consider serotonin syndrome.
Treat serotonin syndrome with cyproheptadine.
If the patient is taking antipsychotics, consider NMS.

Vilazodone Mechanism of Action

Vilazodone is a partial agonist at the 5-HT1A receptor.
Absorption and bioavailability are reduced by half if taken on an empty stomach.
Take vilazodone with food.
Vilazodone may enhance serotonergic activity and contribute to antidepressant actions.

Treatment Considerations for Depression

SSRIs, SNRIs, and atypical antidepressants are reasonable first-line treatments for depression.
MAOIs and TCAs should generally be used after other options have been exhausted due to their higher side effect burden and lethality risk in overdose.
Avoid mirtazapine if weight gain is a concern.
Avoid SSRIs if sexual side effects are a concern.
Consider fluoxetine for patients who often forget to take medications.
Use sertraline during pregnancy.

Brain-Derived Neurotrophic Factor (BDNF) and Depression

Decreased BDNF levels are associated with increased depressive symptoms.
SSRIs increase BDNF levels.

Extrapyramidal Symptoms (EPS)

EPS are caused by D2 blockade in the nigrostriatal pathway.
Acute Dystonia: Sustained muscle contraction, laryngospasm, oculogyric crisis. May be mistaken for agitation.
Akathisia: Restlessness, inability to sit still. May be mistaken for anxiety.
Parkinsonism: Tremors, rigidity, mask-like expression, shuffling gait. May be confused with emotional blunting. Treat with benztropine, diphenhydramine, or amantadine.
Tardive Dyskinesia: Involuntary abnormal muscle movements of the face, mouth, trunk, and extremities. Caused by chronic D2 blockade. Treat with VMAT2 inhibitors (e.g., valbenazine, deutetrabenazine).

Clozapine-Specific Side Effects

Clozapine can cause agranulocytosis, a serious blood disorder with low neutrophils.
Monitor complete blood counts weekly for six months and biweekly thereafter.
Discontinue clozapine and administer filgrastim (colony stimulating factors) if agranulocytosis develops.

Risperidone-Specific Side Effects

Risperidone can cause hyperprolactinemia (increased prolactin) due to D2 blockade in the tuberoinfundibular pathway.
Obtain prolactin levels at baseline and at three months.
Consider reducing the dose or adding aripiprazole to manage hyperprolactinemia if necessary.

Iloperidone-Specific Side Effect

Iloperidone can cause orthostatic hypotension due to α1-adrenergic receptor blockade.

Antidepressants

Mirtazapine + SNRI = increased efficacy for depression
Fluoxetine + olanzapine= treatment for bipolar depression
Lexapro + buspar= similar effects to vilazodone due to 5-HT1A partial agonism
Vortioxetine + bupropion= decrease vortioxetine dose by half due to bupropion increasing vortioxetine serum levels

SSRI Sexual Side Effects

Citalopram and vortioxetine have fewer sexual side effects compared to other SSRIs.
Paroxetine has higher sexual side effects.

Switching Between MAOIs and SSRIs

There is an increased risk of serotonin syndrome if initiating an SSRI too quickly after discontinuing an MAOI.
Wait two weeks after discontinuing an MAOI to initiate an SSRI.
Wash out the SSRI before starting an MAOI, although the washout period is shorter compared to MAOI washout.
If switching from an MAOI to an SSRI, wait two weeks for the enzyme to regenerate.
If switching from an SSRI to an MAOI, wait one to five weeks for the SSRI to clear from the system.

AIMS Examination

Purpose: Used to assess for tardive dyskinesia.
Scoring: Score the highest amplitude or frequency of a movement, not the average.
Interpretation: A score of 2 or greater in two or more areas suggests probable tardive dyskinesia. A score of 3 or greater in one area suggests tardive dyskinesia.

Dopamine Pathways

Nigrostriatal pathway: Involved in movement. Decreased dopamine in this pathway leads to EPS (acute blockade) and TD (chronic blockade).
Mesolimbic pathway: Involved in emotions and positive symptoms of psychosis. Increased dopamine in this pathway can contribute to psychotic symptoms.
Mesocortical pathway: Involved in negative symptoms of psychosis (e.g., emotional blunting, cognitive problems). Decreased dopamine in this pathway can contribute to these symptoms.
Tuberoinfundibular pathway: Involved in prolactin regulation. Decreased dopamine in this pathway can lead to hyperprolactinemia.

Neuroleptic Malignant Syndrome (NMS)

Signs and symptoms: Fever, encephalopathy, unstable vital signs (tachycardia, labile BP, diaphoresis), elevated creatine kinase, muscle rigidity.
Treatment: Discontinue the causative medication, administer muscle relaxants (e.g., dantrolene) and dopamine agonists (e.g., bromocriptine).

Long-Acting Injectable (LAI) Antipsychotics

LAI Use: Recommended for patients with difficulty adhering to oral medications.
LAI Types: Invega Trinza (longest-acting), Invega Sustenna.
Starting LAIs: An oral trial of the medication is required first to ensure tolerability.

First-Generation (Typical) Antipsychotics

Low Potency: chlorpromazine
High Potency: Fluphenazine, Haloperidol, Loxapine, Perphenazine, Pimozide.
Side Effects: Chlorpromazine is associated with more sedation and anticholinergic effects. Fluphenazine, Haloperidol, and Pimozide have high risk of EPS. All FGAs can cause TD.

Acetylcholine and Schizophrenia

Cognitive impairments (e.g., executive functioning, attention, memory) in schizophrenia are linked to acetylcholine downregulation and cholinergic receptor disruptions.

VMAT2 Inhibitors

VMAT2 inhibitors bind to dopamine in the presynaptic neuron, decreasing postsynaptic dopamine levels.
Examples: Valbenazine, deutetrabenazine.
Used to treat tardive dyskinesia.

Muscarinic Receptors

Blockade of H1-histaminic receptors (antihistaminic): Sedation and weight gain.
Blockade of M1-muscarinic cholinergic receptors (anticholinergic): Dry mouth, blurred vision, urinary retention, constipation, drowsiness.
Blockade of α-1 adrenergic receptors: Dizziness, orthostatic hypotension, drowsiness.
Blockade of receptors other than dopamine or serotonin contributes to side effects of antipsychotics, such as sedation, weight gain (histamine), and hypotension (alpha).

Antipsychotic Side Effects

Weight gain and metabolic dysfunction: Olanzapine, clozapine.
EPS: First-generation antipsychotics, risperidone, paliperidone.
Receptors and pathways: Histamine H1 (weight gain, sedation), alpha 1 adrenergic (hypotension), M1 muscarinic (anticholinergic).

Second-Generation (Atypical) Antipsychotics

Clozapine: Treatment-resistant cases. Positive and negative symptoms. High risk of agranulocytosis. Monitor with REMS registry.
Aripiprazole: D2 partial agonist. Risk of akathisia. Less weight gain and sedation. Available in LAI. Long half-life.
Brexpiprazole: D2 partial agonist. Risk of akathisia. Less weight gain and sedation. Good for depression. May improve cognition. Approved for agitation in Alzheimer's.
Risperidone: Potent D2 blocker (EPS). Hyperprolactinemia. Available in LAI.
Paliperidone: Potent D2 blocker (EPS). Hyperprolactinemia. Available in LAI. Approved for schizoaffective disorder.
Ziprasidone: QT prolongation risk. Less sedation, less weight gain. Obtain ECG before starting.
Olanzapine: Weight gain, sedation. Risk of DRESS syndrome. Approved for bipolar depression.
Quetiapine: Sedation, weight gain, metabolic dysfunction. Dose at night. Approved for bipolar depression, depression, mania, psychosis. Different doses have different effects.
Iloperidone: Can cause hypotension. Start low and titrate slowly. Minimal EPS or metabolic side effects.
Asenapine: Sublingual. Good for patients who are cheeking medication. PRN option. Can be used for non-compliant patients before starting LAI.
Lurasidone: Approved for bipolar depression, not mania. Only atypical without QT prolongation risk. Must be taken with food.
Cariprazine: D2 and D3 partial agonist. Long half-life. Approved for bipolar depression. Good for patients with negative symptoms.
Lumateperone: Approved for bipolar depression. Pro-social effects. Minimal weight gain, metabolic dysfunction, EPS.

First-Generation (Typical) vs Second-Generation (Atypical) Antipsychotics

Both FGA and SGA block D2. The key difference is that SGA also block 5-HT2A.
Both FGAs and SGAs manage positive symptoms of psychosis.

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Description

This quiz focuses on differentiating between serotonin syndrome and neuroleptic malignant syndrome (NMS), highlighting the importance of medication assessment. It also explores the mechanism of action of vilazodone and treatment considerations for depression. Test your understanding of these critical psychiatric concepts.