Question
In managing a 70-year-old patient with a history of schizophrenia who is currently being treated for drug-induced Parkinson’s disease, which medication could likely be responsible for side effects such as constipation, blurred vision, and dry mouth?
| A. |
Lithium
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| B. |
Pramipexole
|
| C. |
Benzhexol
|
| D. |
Selegiline
|
Show Answer
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Correct Answer � C
Explanation
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The drug that may be responsible for the above symptoms is Benzhexol.
Benzhexol, also known as trihexyphenidyl, is an anticholinergic medication commonly used to treat the extrapyramidal symptoms (EPS) associated with the use of antipsychotic drugs such as drug-induced Parkinson’s disease.
EPS includes symptoms such as tremors, rigidity, and bradykinesia. Benzhexol works by blocking the action of acetylcholine, a neurotransmitter in the brain that is involved in motor control.
However, because benzhexol blocks acetylcholine, it can also cause a number of anticholinergic side effects, such as constipation, blurred vision, and dry mouth, which are consistent with the symptoms described in the scenario.
Reasons to rule out other options:
Option A. Lithium is a mood stabilizer that is commonly used to treat bipolar disorder. While it can cause a number of side effects, including tremors and polyuria, the symptoms described in the scenario are not typically associated with lithium use.
Option B. Pramipexole is a dopamine agonist that is commonly used to treat Parkinson’s disease. While it can cause a number of side effects, including constipation, the other symptoms described in the scenario are not typically associated with pramipexole use.
Option D. Selegiline is a selective monoamine oxidase B (MAO-B) inhibitor that is commonly used to treat Parkinson’s disease. While it can cause a number of side effects, including dry mouth, the other symptoms described in the scenario are not typically associated with selegiline use.
