RN, BSN
First-generation antipsychotics, also known as typical antipsychotics, were developed in the 1950s. The mechanism of action is blocking the neuroreceptor dopamine, which is believed to be elevated in disorders including schizophrenia.
Second-generation antipsychotics, also known as atypical antipsychotics, were developed in the 1950s. The mechanism of action is blocking both neuroreceptors dopamine and serotonin.
Both classes most commonly treat schizophrenia, acute mania, and bipolar disorder. It can also be used as adjuvant therapy for major depressive disorder. Understanding the differences between typical vs atypical antipsychotics can prepare nurses to better monitor a patient’s treatment and give them the resources to help assuage the patient’s concerns.
First-generation antipsychotics include medications like Thorazine, Haldol, Navane, and Loxitane. These medications are used to treat disorders including schizophrenia, acute mania, and bipolar disorder.
However, these medications may have off-label uses so when a patient is on one of these medications it is important to investigate the reasoning. For example, Thorazine can be given for nausea and vomiting in pregnancy, as well as migraines. Haldol can also be used for aggression, as well as chemotherapy-induced nausea and vomiting.
Second-generation antipsychotics include Abilify, Clonzapine, Zyprexa, and Seroquel. These medications, like first generations, also treat schizophrenia, bipolar disorder, and acute mania – but can also have off-label uses.
For example, all these medications can also be used to treat aggression, and Zyprexa specifically can also be used for chemotherapy-induced nausea and vomiting.
Even though these classes of medications seem to be very similar, the biggest difference between them is their side effects. This stems from their mechanism of action, and how it affects our bodies.
First-generation (typical) antipsychotics cause a large blockade of the neuroreceptor dopamine. Dopamine levels are thought to be elevated in schizophrenia and bipolar disorder, so by blocking dopamine receptors, the levels decrease. First-generation antipsychotics work very effectively for the positive symptoms of schizophrenia, including hallucinations and delusions.
However, this can cause movement disorders including tardive dyskinesia, pseudoparkinsonism, and extrapyramidal symptoms. Movement disorders are common with first-generation antipsychotics because dopamine helps muscles communicate and move smoothly, so when dopamine is lost movement becomes jerky and uncontrolled.
In Parkinson’s, there is a decrease in the level of dopamine. Therefore, this results in the jerky stiff movements that are exhibited in people with this disorder. Pseudoparkinsonism is categorized by movements a patient displays that mimics that of Parkinson’s, including tremors, slow gait, and loss of balance.
Tardive dyskinesia is the uncontrolled, stiff, jerky movements of the face and body. This can exhibit in a lot of ways. Most commonly, it can cause lip smacking, sticking out the tongue, chewing, and quick blinking of the eyes. This is all done involuntarily. However, tardive dyskinesia can also present as wiggling the fingers, waving the arms, and repeated tapping of the feet.
Extrapyramidal symptoms (EPS) include akathisia, acute dystonia, and neuroleptic malignant syndrome. Akathisia is categorized by restlessness and the need for constant movement. Acute dystonia includes involuntary contracting of the muscles, most commonly in the head and neck.
This includes protruding tongue, twisting the head, and extending the neck. Acute dystonia can cause choking or trouble breathing if the muscles in the neck are affected.
Lastly, neuroleptic malignant syndrome, the rarest symptom, is the most serious. This is categorized by rapid onset of fever, confusion, lethargy, and can progress to seizures or coma.
Second-generation antipsychotics cause a blockade of both the dopamine and serotonin neuroreceptors. Unlike first-generation antipsychotics that block mostly the dopamine receptor, second-generation antipsychotics block mostly serotonin neuroreceptors, and that is why the side effects of these drugs differ so much.
Instead of movement disorders with first-generation antipsychotics which are caused by the blockade of dopamine, second-generation antipsychotics cause metabolic side effects such as weight gain or hyperglycemia.
Exactly why second-generation antipsychotics cause weight gain is not yet understood; however, it is believed that it has to do with the blockade of serotonin. Medications that block serotonin have been linked to increased food intake.
This means that medications like clozapine and olanzapine which have the strongest blockade on serotonin also affect weight the most. Weight gain will most commonly occur in the first few weeks of starting the medication, however it can go on for the full duration of taking the medication.
As nurses, it is crucial to be aware of this because patients may abruptly stop their medication due to this, or the weight gain can cause more of a strain on a patient’s mental health.
As the most trusted profession, nurses play a huge role in keeping patients safe who are taking these medications. This includes assessing the patient for side effects, assessing the efficacy of the medication, and ensuring medication coherency.
Nurses also play an important role in building a trusting relationship between the patient and medical professionals. It takes extreme vulnerability for a patient to speak up about their mental health, so it is important nurses are respectful, empathetic, and patient when speaking with patients. Once a relationship is built, patients will feel more comfortable discussing side effects and how they feel the medication is working.
Another huge aspect is education. Nurses must educate the patient on how to take the medication, side effects, what to do when side effects occur, and most importantly – not abruptly stopping the medication. Nurses also need to educate and motivate their patients not to give up.
Trying to find the right medication for a patient comes in trial and error. Every medication’s efficacy as well as its side effects presents differently in each patient, so it is important to emphasize that it may take time to find the right out for the patient. It is crucial as nurses to support patients, as this process makes many feel like they are incurable.
One of the most important things to remember while working as a nurse is understanding every unit deals with mental health – not just psychiatric units. Nurses need to consider the toll it takes on a patient’s mental health while they are in the hospital and be a source of support and hope for their patients.
Mental health diagnoses are steadily increasing and as nurses, we have the power to de-stigmatize and start the conversation with our patients about medications to help their mental health.
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