Pharmacology for Technicians PTCB Test Prep

PTCB Guide to Antipsychotic Drugs.

May 25th, 2024
ptcb guide to antipsychotic drugs

Introduction to Antipsychotic Drugs.

Antipsychotic drugs are routinely tested on the PTCB exam. There are many different families and examples of antipsychotic drug, but you aren’t expected to know them all.

However, there are fifteen antipsychotic drugs that routinely get tested, all of which we cover over the course of this revision guide. Again, it’s about knowing the core details – you aren’t expected to cover each drug in granular detail.

As always, focus on:

  • Key indications
  • Mechanism of action
  • Major side effects
  • Major food-drug or drug-drug interactions

Mechanism of action will be a little different with antipsychotic drugs for two reasons:

  • The mechanism of action of many antipsychotic drugs is not yet completely understood.
  • Some mechanisms which are known as require an in-depth understanding of pharmacology – a level too detailed to be tested on the pharmacy technician exam.

In our review of antipsychotic drugs, we will only reference a drug’s mechanism of action if it’s worth knowing. Where mechanisms are not provided, you can assume not to be expected to know those mechanisms. Toward the end of this PTCB guide to antipsychotic drugs, we have put together some sample questions that test your understanding of what you have learned here.

Indications are broadly similar, in that all antipsychotic drugs are used to treat either or both:

  • Schizophrenia
  • Bipolar disorder

But what are the differences between schizophrenia and bipolar disorder?

Differences between Schizophrenia and Bipolar Disorder.

Both schizophrenia and bipolar disorder are prevalent in the United States.

Bipolar disorder is more common than schizophrenia, affecting approximately 2.8% of the population. In contrast, schizophrenia affects approximately 1% of the population.

Whilst there are some similarities between the two, there are notable differences:

  • In bipolar disorder, patients experience rapid shifts in their mood state – shifting from elated, highly energetic, and irritable to extreme bouts of sadness, depression, and hopelessness. This shift between the two is what characterizes bipolar disorder – the name itself, “bipolar”, referring to opposite poles of a mood spectrum.
  • What characterizes schizophrenia is the presence of delusions and hallucinations. Other symptoms of schizophrenia include social withdrawal, aggression, and loss of interest day to day. Affected patients may also do or say strange or inappropriate things.

Though there are notable differences between schizophrenia and bipolar disorder, many antipsychotic drugs are used to treat both conditions. Some antipsychotic drugs are only used to treat one of these conditions, though.

Antipsychotic Drug Review.

Here, we separated the fifteen must-know antipsychotic drugs according to their wider drug class.

These drug classes include:

  • Butyrophenones
  • Phenothiazines
  • Benzamides
  • Benzisoxazoles / benzisothiazoles
  • Tricyclics

Whilst most of these drug class terms are unlikely to be tested on the PTCB exam, it is worth remembering the following three: butyrophenones, phenothiazines, and tricyclics.

In the table below, note the common suffix of each class to assist your identification of the drug. For instance, you may be asked to identify an antipsychotic drug from a list of four drugs. Knowing these suffixes can help you select the correct answer.

Drug ClassExampleCommon Brand

Mechanism of Action.

A common mechanism of action among many antipsychotic drugs is targeting the dopamine, D2 receptor.

Antipsychotic drugs tend to block this receptor, lessening the amount of dopamine released. This includes drugs such as haloperidol and chlorpromazine, but the mechanism is not limited to these drugs.

Excess dopamine release has been linked to psychotic experiences. Blocking this receptor helps to modulate the amount of dopamine in the brain, reducing the prevalence of psychotic effects.

Of course, blocking dopamine is only one part of the total mechanism of how antipsychotic drugs work. These drugs have complex effects in the brain that affect other neurotransmitters, too – notably serotonin receptors. However, for the PTCB exam you will not be tested on these additional mechanisms.

Side Effects.

Antipsychotic drugs have many shared side effects. These include:

  • Sedation
  • Weight gain – highest risk with clozapine and olanzapine
  • Hyperprolactinemia – high risk with risperidone
  • Headache
  • Dizziness
  • Anxiety
  • Anticholinergic side effects – high risk with olanzapine

Extrapyramidal side effects are common with first-generation antipsychotics (haloperidol, chlorpromazine). Characteristics of extrapyramidal side effects include:

  • Akathisia – restlessness
  • Dystonia – abnormal muscle contractions
  • Parkinson-like effects – rigidity, tremors

Of all antipsychotic drugs, it’s worth considering the adverse effects of clozapine, as it is well-known for having many serious adverse effects. That is why clozapine comes with its own REMS (Risk Evaluation and Mitigation Strategy) due to the risk of severe neutropenia.

Other adverse effects of clozapine include:

  • Agranulocytosis – dangerously low white blood cell count.
  • Myocarditis – inflammation of the heart.
  • Hyperglycemia – high blood sugar levels.
  • Orthostatic hypotension – low blood pressure when standing up.
  • Seizures – clozapine lowers the seizure threshold.

For the PTCB exam, you should know about the clozapine REMS, as well as the additional risks this medicine has for patients when compared to other antipsychotic drugs.

PTCB Sample Questions.

You can find the answers to these PTCB questions in the conclusion below.

Q1. What is the active ingredient of the medicine, Seroquel?

a. Amisulpride

b. Aripiprazole

c. Quetiapine

d. Haloperidol

Q2. Blockade of which dopamine receptor is most responsible for antipsychotic effects?

a. D1 receptor

b. D2 receptor

c. D3 receptor

d. D4 receptor

Q3. Which antipsychotic drug carries the highest risk of weight gain?

a. Aripiprazole

b. Lurasidone

c. Amisulpride

d. Olanzapine

Q4. Due to its adverse effects, which antipsychotic drug has a REMS program?

a. Prochlorperazine

b. Droperidol

c. Clozapine

d. Risperidone

Q5. Extrapyramidal side effects are most likely with which of the following?

a. First-generation antipsychotics

b. Second-generation antipsychotics

c. Both first and second-generation antipsychotics

d. Extrapyramidal side effects do not occur with antipsychotics


Answers to the PTCB sample questions:

A1. Quetiapine is the active ingredient of the medicine, Seroquel.

A2. The dopamine D2 receptor is blocked to produce most antipsychotic effects.

A3. Among antipsychotic drugs, olanzapine carries the highest risk of weight gain.

A4. Clozapine has a REMS program (Risk Evaluation and Mitigation Strategy).

A5. Extrapyramidal side effects are more common with first-generation antipsychotic drugs – such as haloperidol and chlorpromazine.

This PTCB guide to antipsychotic drugs gives you the detail you need to know for the PTCB exam. We covered all necessary knowledge domains – from indications to mechanism of action to side effects – that you need to know. You aren’t expected to know all drug interactions as there are too many.

That said, note that alcohol will always worsen CNS-related side effects of these drugs (such as sedation and anxiety) and for that reason should not be taken with these medicines. Alcohol can also worsen the hypotensive effects of some of these drugs – most notably clozapine.

We hope you found this PTCB guide to antipsychotic drugs helpful. Check back to our PTCB blog soon for more exclusive content to help you study and pass the pharmacy technician exam.

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PTCB Test Prep Author


Elaine Walker

Elaine joined PTCB Test Prep in 2017, currently serving as the lead product development manager overseeing both course development and quality improvement. Mrs. Walker is a graduate of California State University and has worked as a pharmacy technician for over twenty years – with particular interests in pediatric pharmacy, extemporaneous compounding, and hospital pharmacy. Over the past 8-years, she has helped prepare thousands of students for the PTCB examination.