Levodopa can cause-
**Core Concept**
Levodopa is a precursor to dopamine, used in the treatment of Parkinson's disease. It works by crossing the blood-brain barrier and being converted to dopamine in the brain, where it can help alleviate motor symptoms. However, its use is associated with several side effects due to its metabolism and interactions with other neurotransmitters.
**Why the Correct Answer is Right**
The correct answer is related to levodopa's metabolism and its interaction with catechol-O-methyltransferase (COMT), an enzyme that breaks down levodopa and dopamine. Levodopa can cause **neurotransmitter imbalance**, particularly an increase in dopamine levels, but also an increase in other catecholamines like norepinephrine and epinephrine. This can lead to symptoms like orthostatic hypotension, tachycardia, and hypertension.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not a known side effect of levodopa.
* **Option B:** Although levodopa can cause nausea and vomiting, this is not the most specific or correct answer choice.
* **Option C:** This option is not directly related to levodopa's mechanism of action or common side effects.
**Clinical Pearl / High-Yield Fact**
It's essential to note that levodopa's efficacy can be increased by administering a peripheral decarboxylase inhibitor, such as carbidopa, which prevents levodopa's conversion to dopamine outside the brain, thereby reducing systemic side effects.
**Correct Answer:** B. Nausea and vomiting