A 41-year-old man has been treated with haloperidol for his schizophrenia for the past 15 year. He begins to notice subtle involuntary movements of this hands, feet, lips, and tongue. Because he had been stable for over 1 year his physician decided to decrease the dose. What would the physician tell the patient about the movement disorder?
**Core Concept**
Haloperidol is a typical antipsychotic medication that blocks dopamine D2 receptors in the brain, which is effective in treating schizophrenia. However, long-term use of haloperidol can lead to a side effect known as tardive dyskinesia (TD), characterized by involuntary, repetitive movements of the face, lips, tongue, and extremities.
**Why the Correct Answer is Right**
The development of tardive dyskinesia is thought to be related to the blockade of dopamine D2 receptors in the nigrostriatal pathway, which is involved in motor control. The prolonged use of haloperidol leads to a supersensitivity of dopamine receptors in the brain, resulting in the abnormal movement patterns seen in TD. The decrease in haloperidol dose is a common strategy to manage this side effect, as it may help alleviate the symptoms of TD.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because haloperidol is not known to cause Parkinson's disease, which is a neurodegenerative disorder characterized by tremors, rigidity, and bradykinesia. While haloperidol can cause extrapyramidal side effects (EPS), such as dystonia and akathisia, these are different from the characteristic symptoms of Parkinson's disease.
* **Option B:** This option is incorrect because the use of haloperidol does not typically lead to the development of essential tremor, which is a benign movement disorder characterized by a tremor that occurs at rest and is often exacerbated by voluntary action.
* **Option C:** This option is incorrect because the symptoms of tardive dyskinesia are typically irreversible, even after discontinuation of the offending medication. However, reducing the dose of haloperidol may help alleviate symptoms and prevent further worsening of the condition.
**Clinical Pearl / High-Yield Fact**
Tardive dyskinesia is a common side effect of long-term use of typical antipsychotic medications, and its risk increases with age and duration of treatment. It is essential for clinicians to monitor patients for signs of TD, particularly those with a history of prolonged antipsychotic use, and to adjust treatment plans accordingly to minimize the risk of this debilitating side effect.
**Correct Answer: D.** The physician would tell the patient that the movement disorder is called tardive dyskinesia, a potential side effect of long-term haloperidol use.