What action do sympathomimetic drugs have in the body?

A) Beta 1-receptors:
Beta 1-receptors are primarily found in the heart, and their stimulation leads to increased heart rate and contractility. These receptors are not typically involved in vasoconstriction, pupil dilation, or piloerection.

B) Beta 2-receptors:
Beta 2-receptors are primarily located in smooth muscles such as the bronchi and blood vessels. Their stimulation causes smooth muscle relaxation, leading to bronchodilation and vasodilation. Beta 2-receptors are not responsible for the effects of vasoconstriction, piloerection, or pupil dilation described in the question, making this option incorrect.

C) Alpha 2-receptors:
Alpha 2-receptors are involved in the inhibition of norepinephrine release and play a role in regulating sympathetic tone. They are not primarily responsible for vasoconstriction or the other physiological responses listed in the question. Alpha 2-stimulation typically results in decreased sympathetic activity, not the effects described here.

D) Alpha 1-receptors:
Alpha 1-receptors are located on smooth muscle, including the blood vessels, and their stimulation results in vasoconstriction. They are also involved in other actions such as piloerection (hair standing on end), pupil dilation (mydriasis), and closure of the salivary sphincter. Additionally, they play a role in male sexual emission (ejaculation). The physiological responses described in the question—vasoconstriction, piloerection, pupil dilation, and male sexual emission—are all consistent with alpha 1-receptor stimulation.

A) Tacrine (Cognex): Tacrine is an acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease to improve cognitive function. It is not typically used for Parkinson's disease, which is characterized by motor symptoms such as tremors, shuffling gait, and rigidity.

B) Rivastigmine (Exelon): Rivastigmine is another acetylcholinesterase inhibitor, similar to Tacrine, primarily used to treat Alzheimer's disease or dementia-related symptoms. While it helps with cognitive symptoms, it is not effective in treating the motor symptoms of Parkinson's disease.

C) Carbidopa-levodopa (Sinemet): This is the correct answer. Carbidopa-levodopa (Sinemet) is the gold standard treatment for Parkinson's disease. Levodopa is a precursor to dopamine, which helps address the dopamine deficiency in the brain that causes symptoms like tremors, shuffling gait, and lack of facial expression (masked facies). Carbidopa is added to prevent levodopa from being broken down before it reaches the brain, enhancing its effectiveness.

D) Donepezil (Aricept): Donepezil is also an acetylcholinesterase inhibitor used primarily in Alzheimer's disease. Like Tacrine and Rivastigmine, it works to improve cognitive function but does not treat the motor symptoms seen in Parkinson's disease. It would not be appropriate for managing the patient's Parkinsonian symptoms.