What are extrapyramidal symptoms (EPS) and which drug class often causes them?

• A. Movement disorders (acute dystonia, akathisia, parkinsonism, tardive dyskinesia) commonly caused by typical antipsychotics.
• B. Digestive issues commonly caused by antidepressants.
• C. Seizures caused by mood stabilizers.
• D. Allergic reactions caused by antipsychotics.

Answer: (A)

Extrapyramidal symptoms are drug-induced movement disorders caused by strong blockade of dopamine D2 receptors in the nigrostriatal pathway. They present as a range of motor effects: acute dystonia (sustained muscle contractions), akathisia (inner restlessness), parkinsonism (tremor, rigidity, slowed movements), and tardive dyskinesia (involuntary movements, often after long-term use). The drugs most likely to cause these are typical (first-generation) antipsychotics, which strongly block D2 receptors and thus disrupt dopaminergic signaling in motor circuits. Atypical antipsychotics have a lower but still possible risk, especially at higher doses. The other options don’t fit EPS because digestive issues, seizures, and allergic reactions involve different biological mechanisms and do not reflect the characteristic motor syndromes produced by nigrostriatal dopamine blockade.