Which of the following catecholamines may have a vasodilator effect on renal blood vessels and be prescribed for a client in shock who are experiencing renal insufficiency manifestations?

A) Parkinson disease is characterized by an imbalance of dopamine and acetylcholine:
The decrease in dopamine results in an imbalance between dopamine and acetylcholine. Normally, dopamine and acetylcholine work in a balanced manner to regulate motor control. As dopamine levels decrease in Parkinson's disease, acetylcholine's effects become more prominent, leading to motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement).

B) Parkinson disease involves increased dopamine production and decreased acetylcholine:
This statement is incorrect. In Parkinson's disease, there is actually a decrease in dopamine production, not an increase. The disease is characterized by the degeneration of dopamine-producing neurons, leading to the motor symptoms typical of Parkinsonism. The imbalance in Parkinson's disease is primarily one of decreased dopamine and relatively increased acetylcholine activity.

C) Alzheimer disease is caused by decreased amounts of dopamine and degeneration of cholinergic neurons:
While Alzheimer's disease does involve a degeneration of cholinergic neurons (specifically those that release acetylcholine), the primary pathology is related to the accumulation of amyloid plaques and tau tangles, not primarily a decrease in dopamine. Alzheimer's disease is primarily associated with a deficiency in acetylcholine, not dopamine, leading to cognitive impairments, rather than motor deficits.

D) Alzheimer disease involves a possible excess of acetylcholine and neuritic plaques:
This statement is incorrect. Alzheimer's disease is characterized by a deficiency of acetylcholine, which plays a crucial role in memory and cognitive function. The hallmark pathologic features of Alzheimer's disease include the presence of neuritic plaques (formed from amyloid beta) and neurofibrillary tangles (composed of tau protein), not an excess of acetylcholine.

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.