8.9 Antipsychotics

Antipsychotic drugs are used to treat drug-induced psychosis, schizophrenia, extreme mania, depression that is resistant to other therapy, and other CNS conditions. Antipsychotics are sometimes referred to as tranquilizers because they produce a state of tranquility. First-generation antipsychotics, also called conventional antipsychotics, have similar mechanisms of action. An example of a conventional antipsychotic is haloperidol. Conventional antipsychotics have several potential adverse effects, and the selection of a medication is based on the client’s ability to tolerate the adverse effects. Second-generation antipsychotics also referred to as atypical antipsychotics, have fewer adverse effects. An example of an atypical antipsychotic is risperidone.^[1] Both conventional and atypical antipsychotics have a Black Box Warning indicating that elderly clients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death.

1st and 2nd Generation Antipsychotics

Mechanism of Action

All antipsychotics block dopamine receptors in the brain. However, the precise mechanism of action has not been clearly established. Conventional antipsychotics, such as haloperidol, block dopamine receptors in certain areas of the CNS, such as the limbic system and the basal ganglia. These areas are associated with emotions, cognitive function, and motor function, and blockage thus produces a tranquilizing effect in psychotic clients. However, several adverse effects are also caused by this dopamine blockade.

Second-generation, or atypical, antipsychotics block specific dopamine 2 receptors and specific serotonin 2 receptors, thus causing fewer adverse effects.

Indications for Use

Haloperidol is primarily indicated for schizophrenia and Tourette’s disorder. Risperidone is primarily indicated for schizophrenia but is also used for acute manic episodes and for irritability caused by autism. Some atypical antipsychotics are also used as an adjunct therapy for depression or nausea.

Nursing Considerations Across the Lifespan

Elderly clients with dementia-related psychosis treated with antipsychotic drugs should be closely monitored for signs and symptoms of cardiovascular events or infections such as pneumonia.

Haloperidol is contraindicated in clients with Parkinson’s disease or dementia with lewy bodies.

Clients who are concurrently taking lithium and antipsychotics should be monitored closely for neurotoxicity (weakness, lethargy, fever, tremulousness, confusion, and extrapyramidal symptoms) and symptoms should be immediately reported.

Adverse/Side Effects

Elderly clients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death due to cardiovascular or infection-related causes.

Conventional antipsychotic medications have several potential serious adverse effects such as tardive dyskinesia, neuroleptic malignant syndrome (NMS), and extrapyramidal symptoms. These adverse effects are due to the blockage of alpha-adrenergic, dopamine, endocrine, histamine, and muscarinic receptors. For additional details about these types of receptors, see the Autonomic Nervous System chapter. Figure 8.8 describes adverse effects associated with conventional antipsychotics. Clients should be warned to not consume alcohol and that their ability to operate machinery or drive a vehicle may be impaired.

Figure 8.8 Potential Adverse Effects of Antipsychotic Medication^[2]

Second-generation, or atypical, antipsychotics are less likely to cause adverse effects but have the potential to do so. Atypical antipsychotics may also cause metabolic changes such as hyperglycemia, hyperlipidemia, and weight gain.

Client Teaching & Education

Advise client to take medication as directed.  Medication doses should be evenly spaced throughout the day.  This drug may take several weeks to manifest desired effects. Clients should be advised regarding the possibility of extrapyramidal symptoms and that abrupt withdrawal may cause dizziness, nausea and vomiting, or uncontrolled movements of mouth, tongue, or jaw.  Additionally, the client should be careful to avoid alcohol or other CNS depressants while using the medication.

Now let’s take a closer look at the medication grid for haloperidol and risperidone in Table 8.9.^[3],[4]

Medication cards like this are intended to assist students to learn key points about each medication. Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication. Basic information related to each class of medication is outlined below.  Prototype or generic medication examples are also hyperlinked to a free resource at Daily Med. On the home page, enter the drug name in the search bar to read more about the medication.

Table 8.9 Medication Card Comparing Antipsychotics.^[5][6][7][8] Haloperidol, Risperidone