Antipsychotics

Question 1

What are antipsychotic drugs?

Answer 1

antipsychotics, also known as neuroleptics, are drugs used primarily to treat psychotic states such as schizophrenia, delusional disorder, and other hallucinatory states

Question 2

What is MOA of antipsychotics?

Answer 2

Antipsychotics block various receptors including cholinergic, adrenergic, serotoninergic, muscarinic, and histamine receptors.
However, their antipsychotic actions are primarily thought to be due to blocking of DOPAMINE RECEPTORS in the CNS, particularly the D2 receptors in the mesocortical & mesolimbal systems of the brain.

Question 3

Do antipsychotic agents differ in potency?

Answer 3

Yes - a drug’s parallels its affinity for D2 receptors.

Question 4

Which antipsychotic drugs are high potency drugs because they have high affinity for D2 receptors

Answer 4

Haloperidol (Haldol)

Thiothixene (Mellaril)

Question 5

Which antipsychotic agents are low-potency drugs because they have low affinity for D2 receptors?

Answer 5

Chlorpromazine (Thorazine)

Thioridazine (Mellaril)

Question 6

Do antipsychotics diifer in efficacy?

Answer 6

NO. the traditional antipsychtoics are all considered to be equivalent in efficacy.

Question 7

What is the onset of action of antipsychotic drugs?

Answer 7

Antipsychtotics may not become effective for several weeks to months. However, sedation and other side effects can occur rapidly

Question 8

Can antipsychotic drugs cure illnesses such as schizophrenia?

Answer 8

NO! antipsychotics only reduce symptoms of illness; they cannot cure

Question 9

How are antipsychotics classified?

Answer 9

Classification is based on structural differences. The major classes include phenothiazines:

1. butyrophenones
2. dibenzoxazepines
3. thioxanthines
4. benzisoxazoles

Question 10

What are some examples of phenothiazines?

Answer 10

1. Chloropromazine (Thorazine) - prototype
2. Fluphenazine (Prolixin)
3. Trifluoperazine (stelline)
4. Thioridazine (Mellaril)
5. Perphenazine (Trilafon)

Question 11

What distinctive side effects does thioridazine (Mellaril) cause?

Answer 11

Pigmentary retinopathy

retinitis pigmentosa

Question 12

Name two drugs int he class Butyrophenones

Answer 12

1. Haloperidol (Haldol)

2. Droperidol (Inapsine)

Question 13

Other psychotic states, for what can Haloperidol be used?

Answer 13

Tourette’s syndrome
Huntingtons Disease
Phencyclindine overdose - DRUG OF CHOICE

Question 14

What type of side effects is especially pronounced with Haloperidol?

Answer 14

Extrapyramidal side effects!
–> Acute dystonia, Akathisia, parkisonism, tardive dyskinesia
COMMON BOARD QUESTION!

Question 15

Name a drug that belongs to the Dibenzoxazepines

Answer 15

Loxapine (Loxitane)

Question 16

Name a drug that belongs to the Thioxanthenes?

Answer 16

Thiothixene (Navane)

Question 17

What are the clinical applications of traditional antipsychotic agents?

Answer 17

traditional neuroleptics have several therapeutic uses, but the most important to remember are:

• Treatment of any agitated or psychotic state
  1. Bipolar disease
  2. Schizophrenia - effective for + symptoms such as delusions, thought disorders, and hallucinations
• Antiemetic therapy - phenothiazines with the exception of thioidazine
• Treatment of Tourette’s syndrome
• Treatment of intractable hiccups
• Antipruritic therapy

Question 18

Treatment of Tourettes syndrome

Answer 18

Haloperidol

Question 19

Treatment of intractable hiccups

Answer 19

Chlorpromazine

Question 20

Treatment - Antipruritic therapy for antipsychotics

Answer 20

Promethazine (bc of histamine blockage)

Question 21

What is an easy way to remember the side effects of the traditional antipsychotics?

Answer 21

With a few exceptions, all of the traditional antipsychotics have similar toxicities - namely , sedation, extrapyramidal effects, anticholinergic effects, and alpha-adrenergic effects (hypotension).

Question 22

Which antipsychotics produce the greatest extrapyramidal effects

Answer 22

Haloperidol and Fluphenazine (Prolixin)

Question 23

Which antipsychotic drugs produce the greatest anticholinergic effects?

Answer 23

Thioridazine & Chlorpromazine

Question 24

Describe the toxicities of traditional antipsychotic agents

Answer 24

1. CNS sedation (Markedly seen with phenothiazines)
2. Endocrine alteration (galactorrhea, amenorrhea, and infertility, likely due to blockade of dopamine release from the pituitary)
3. Antiadrenergic effects - (watch for light headedness and orthostatic hypotension secondary to alpha-adrenergic blockade. Phenothiazines can cause sexual dysfunction *FAILURE TO EJACULATE!!
4. Extrapyramidal side effects - akathisia (most or restlessness); parkinsonian syndrome (bradykinic rigidity, tremor); acute dystonic reactions, neuroleptic malignant syndrome, and tar dive dyskinesia
   * **COMMON BOARD QUESTION

Question 25

What is tar dive dyskinesia

Answer 25

symptom that may occur after prolonged therapy with neuroletpics (4 months to 1 year). It is characterized by rhythmic involuntary movements of the tongue, lips, or jaw. Patients may also demonstrate puckering of the mouth or even chewing movements.

Question 26

Is tardive dyskinesia reversible?

Answer 26

There is no known treatment for established cases of tar dive dyskinesia. They symptom may remit partially or completely if neuroleptic treatment is withdrawn, although in many cases it is irreversible. Anticholinergic agents actually increase the severity of tardive dyskinesia.

Question 27

What is an acute dystonic reaction?

Answer 27

prolonged muscle spasms of tongue, neck, or face

Question 28

What are acute dystonic reactions treated?

Answer 28

Patients are given Diphenhydramine (Benadryl) or an injection of Benztropine.

Question 29

What is neuroleptic malignant syndrome?

Answer 29

Patients who receive neuroleptics for long-term treatment may experience rigidity, altered mental status, cardiac arrhythmias, hypertension, and life-threatening hyperpyrexia.

Question 30

What is the therapy for neuroleptic malignant syndrome?

Answer 30

This disorder is treated with Dantrolene , a skeletal muscle relaxant! **COMMON BOARD QUESTION!

Question 31

Name 6 examples of atypical antipsychotic drugs

Answer 31

1. Clozapine (clozaril) 2. Risperidone (Risperdal) 3. Olanzapine (Zyprexa) 4. Aripiprazole (Abilify) 5. Quetiapine (Seroquel) 6. Ziprasidone (Geodon)

Question 32

Why are these drugs considered "atypical"?

Answer 32

They are newer and in addition to blocking dopamine receptors, atypical antipsychotics also produce significant therapeutic effects through the blockade of serotonin (5-HT2) receptors. They are also rarely associated with extrapyramidal side affects.

Question 33

Are they more effective than traditional antipsychotics?

Answer 33

Most physicians consider them a better choice for therapy because of their decreased side effects

Question 34

Describe the actions of clozapine

Answer 34

this agent is a dibenzodiazepine derivative. It differs from traditional antipsychotics in its potent blockade of serotonin (5-HT2) receptors, along with the usual dopamine blockade.

Question 35

What is clonazapine used for?

Answer 35

schizophrenia that are refractory to other neuroleptic drugs. It is especially effective in treating NEGATIVE SYMPTOMS of schizophrenia - blunted emotion, withdrawal, reduced ability to form relationships

Question 36

side effects of clozapine

Answer 36

fewer extrapyrimidal side effects than traditional neuroleptics. * DOES CAUSE SEIZURES & DANGEROUS AGRANULOCYTOSIS * **common board question - - weekly blood tests are required for patients receiving clozapine therapy. - although WEIGHT GAIN can occur with extended treatment of most antipsychotics, it is ESPEICLALY PROMINENT WITH CLOZAPINE. (this can lead to hypertension)

Question 37

Describe the actions of Risperidone (Risperdal).

Answer 37

benzisoxazole drug that, like clozapine, has a very high affinity for 5-HT2 receptors. It also has antidopaminergic D2 activity.

Question 38

What is the first line agent for the treatment of schizophrenia, since it is effective for both the positive and negative symptoms of the disease?

Answer 38

Risperidone (Risperdal) The drug is also known to prolong QT intervals and therefore should be used with caution in patients who have abnormal QT intervals.

Question 39

Side effects of Risperidone (Risperdal)?

Answer 39

However, risperidone exhibits no anticholinergic effects and diminished extrapyramidal effects. The drug is also known to prolong QT intervals and therefore should be used with caution in patients who have abnormal QT intervals.

Question 40

MOA of Olanzapine (Zyprexa)

Answer 40

blocks both dopamine and serotonin receptors

Question 41

Clinical use of Olanzapine (Zyprexa)

Answer 41

effective in the treatment of both positive and negative symptoms of schizophrenia, depression, or Obsessive-compulsion disorder (OCD)

Question 42

Side effects of Olanzapine (Zyprexa)

Answer 42

anticholinergic effects and othrostatic hypertension | HIGH RISK OF WEIGHT GAIN & METABOLIC SYNDROME!!!

Question 43

only antipsychotic drug used that is a partial agonist at D2 receptors

Answer 43

Aripiprazole (Abilify)