The major difference between typical and atypical antipsychotics is that
**Core Concept**
Typical and atypical antipsychotics are two categories of medications used to treat schizophrenia and other psychoses. The primary distinction between these two groups lies in their side effect profiles, particularly their propensity to cause extrapyramidal symptoms (EPS).
**Why the Correct Answer is Right**
Typical antipsychotics, such as haloperidol, block dopamine D2 receptors in the striatum, leading to an imbalance between dopamine and acetylcholine. This results in the development of extrapyramidal symptoms, including tremors, rigidity, and most notably, tardive dyskinesia. Tardive dyskinesia is a type of movement disorder characterized by involuntary, repetitive movements of the face, tongue, and limbs. Atypical antipsychotics, such as olanzapine and quetiapine, have a more balanced effect on dopamine and serotonin receptors, reducing the risk of EPS and tardive dyskinesia.
**Why Each Wrong Option is Incorrect**
**Option A:** Atypical antipsychotics can still cause some increase in prolactin levels, although typically less than typical antipsychotics.
**Option C:** Both typical and atypical antipsychotics are available as parenteral preparations, making this statement incorrect.
**Option D:** Atypical antipsychotics can cause sedation, but it is not a defining characteristic that differentiates them from typical antipsychotics.
**Clinical Pearl / High-Yield Fact**
To remember the difference between typical and atypical antipsychotics, use the mnemonic "BLOCKS": "B" for blocking dopamine receptors (typical), "L" for low risk of EPS (atypical), "O" for older medications (typical), "C" for causing EPS (typical), "K" for keeping patients awake (atypical), "S" for sedation (atypical).
**✓ Correct Answer: B. The former cause tardive dyskinesia**