Antipsychotics are among the most important classes of psychiatric medications, primarily used in the management of psychotic disorders such as schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis. These drugs work by altering neurotransmitter activity in the brain—especially dopamine and serotonin—thereby controlling symptoms like hallucinations, delusions, thought disorganization, and agitation.
Over the years, antipsychotic medications have evolved into two main categories: First-Generation Antipsychotics (FGAs) and Second-Generation Antipsychotics (SGAs). Understanding the differences between these two types is essential for safe and effective patient care.
Classification of Antipsychotics
First-Generation Antipsychotics (FGAs)
Also called typical or conventional antipsychotics, these were the first drugs developed to treat psychosis.
Examples:
- Chlorpromazine
- Haloperidol (Haldol)
- Loxapine (Adasuve)
Mechanism of Action:
- Blocks/inhibits dopamine (D2) receptors in the brain.
- Reduces positive symptoms of schizophrenia (hallucinations, delusions, disorganized thoughts).
Limitation:
- Less effective against negative symptoms (apathy, flat affect, withdrawal).
- Higher risk of movement disorders such as tardive dyskinesia (TD) and extrapyramidal syndrome (EPS).
Second-Generation Antipsychotics (SGAs)
Also known as atypical antipsychotics, these newer medications provide broader symptom control and fewer motor side effects.
Examples:
- Risperidone (Risperdal)
- Clozapine (Clozaril)
- Quetiapine (Seroquel)
- Ziprasidone (Geodon)
- Aripiprazole (Abilify)
Mechanism of Action:
- Act on both dopamine (D2) and serotonin (5-HT2A) receptors.
- Reduce both positive and negative symptoms of schizophrenia.
- Lower risk of movement disorders compared to FGAs.
Side Effects of Antipsychotics
Side Effects of FGAs:
- Higher risk of Tardive Dyskinesia (TD), Extrapyramidal Symptoms (EPS), and Neuroleptic Malignant Syndrome (NMS)
- Orthostatic hypotension (sudden drop in BP when standing)
Side Effects of SGAs:
- Lower risk of TD, EPS, and NMS compared to FGAs
- Weight gain
- Increased cholesterol and triglycerides
- Elevated blood sugar (risk of diabetes)
Side Effects Common to Both FGAs and SGAs:
- Anticholinergic effects (dry mouth, blurred vision, constipation, urinary retention)
- Photophobia (sensitivity to light)
- Photosensitivity (skin sensitivity to sunlight)
- Sedation, lethargy, drowsiness
Serious Complications
1. Tardive Dyskinesia (TD)
- Involuntary, repetitive movements of the face, tongue, or limbs
- May be irreversible with prolonged drug use
2. Extrapyramidal Syndrome (EPS)
- Parkinson-like symptoms (tremors, rigidity, bradykinesia)
- Akathisia (restlessness, inability to sit still)
- Dystonia (muscle spasms, abnormal postures)
- Rare but life-threatening
- Symptoms: high fever, autonomic disturbance, muscle rigidity, altered mental status
- Can recover 7–10 days after discontinuation, but fatal if untreated
Contraindications of Antipsychotics
Antipsychotics should be used cautiously or avoided in patients with:
- Hypersensitivity to the drug
- Comatose state
- Severe depression
- Bone marrow suppression or blood dyscrasias
- Parkinson’s disease
- Liver disease
- Coronary artery disease
- Severe hypo/hypertension
Nursing Considerations
Nurses play a critical role in ensuring safe and effective use of antipsychotics.
General Nursing Guidelines:
- Educate patients that full effects may take 6–10 weeks.
- Stress the importance of adherence, even when symptoms improve.
- Teach clients about possible side effects and when to report them.
Specific Nursing Interventions:
For FGAs:
- Monitor for signs of TD, EPS, and NMS.
- Advise clients to rise slowly to prevent orthostatic hypotension.
For SGAs:
- Regularly check labs (blood sugar, lipids).
- Monitor weight gain.
- Educate about diet and exercise to reduce metabolic risks.
Comparison Table: FGAs vs SGAs
| Feature | FGAs (Typical) | SGAs (Atypical) |
|---|---|---|
| Mechanism | Block dopamine receptors | Block dopamine & serotonin receptors |
| Symptom control | Positive symptoms only | Both positive & negative symptoms |
| Side effects | High risk of EPS, TD, NMS | Lower risk of EPS, but risk of weight gain, diabetes, lipid abnormalities |
| Examples | Haloperidol, Chlorpromazine | Risperidone, Clozapine, Quetiapine |
| Best use | Acute psychosis, agitation | Long-term schizophrenia, bipolar disorder |
Frequently Asked Questions (FAQ)
Q1. Why are SGAs considered better than FGAs?
SGAs control both positive and negative symptoms of schizophrenia and carry a lower risk of movement-related side effects.
Q2. How long do antipsychotics take to work?
It may take 6–10 weeks for full therapeutic effect, although some symptom relief may occur earlier.
Q3. Can antipsychotics cure schizophrenia?
No. Antipsychotics control symptoms but do not cure the underlying condition. Lifelong treatment may be necessary.
Q4. Which antipsychotic is most effective for treatment-resistant schizophrenia?
Clozapine is the drug of choice for treatment-resistant schizophrenia, though it requires monitoring for agranulocytosis.
Q5. What should patients avoid while on antipsychotics?
Alcohol, sedatives, and excessive sun exposure (due to photosensitivity). Patients should also avoid abrupt discontinuation.
