After norepinephrine is released, it binds to receptors on the target organs. Then, it must be removed from the synaptic space. Which of the following mechanisms describes correct removal of norepinephrine from the synaptic space?

Correct Answer: D

Rationale: The correct answer is D) Metabolism to O-methylated derivatives in the synaptic space. Norepinephrine is removed from the synaptic space through the process of metabolism to O-methylated derivatives by the enzyme catechol-O-methyltransferase (COMT). This process helps in the breakdown of norepinephrine, preventing its prolonged action on the target organs. Option A) ATPase pump is stimulated by cocaine is incorrect because cocaine inhibits the reuptake of norepinephrine rather than stimulating the ATPase pump. Option B) ATPase pump is stimulated by imipramine is incorrect because imipramine is a tricyclic antidepressant that inhibits the reuptake of norepinephrine rather than stimulating the ATPase pump. Option C) Diffusion from the general circulation back into the synaptic space is incorrect because norepinephrine is primarily metabolized in the synaptic space rather than diffusing back from the general circulation. Understanding the mechanisms of norepinephrine removal from the synaptic space is crucial in pharmacology, especially when studying drugs that affect its metabolism and reuptake. This knowledge is essential for healthcare professionals to understand the actions and effects of drugs targeting the central nervous system and related neurotransmitters.

Correct Answer: A

Rationale: The correct answer is A) Benztropine. Benztropine is an anticholinergic medication commonly used to treat the symptoms of Parkinson's disease, such as tremors and rigidity, by blocking the action of acetylcholine in the central nervous system. Acetylcholine is involved in the regulation of muscle movement, and blocking its effects can help alleviate the motor symptoms of Parkinson's disease. Option B) Bromocriptine is a dopamine agonist used in the management of Parkinson's disease, but it primarily works by stimulating dopamine receptors rather than blocking acetylcholine, making it less effective for treating tremors and rigidity. Option C) Ipratropium is a bronchodilator used to treat respiratory conditions such as COPD and asthma by dilating the airways. It is not indicated for the treatment of Parkinson's disease symptoms. Option D) Scopolamine is an anticholinergic medication used primarily for motion sickness and nausea, not for the management of Parkinson's disease symptoms. In an educational context, understanding the mechanisms of action of different medications is crucial for making appropriate treatment decisions. Knowing the specific indications and contraindications of drugs helps healthcare professionals provide optimal care for patients with various conditions like Parkinson's disease. It is essential for nursing students and healthcare providers to be able to differentiate between medications with similar indications to ensure safe and effective patient care.

Correct Answer: D

Rationale: The correct answer is D) Risperidone. Risperidone has the highest affinity for \(D_2\) receptors among the options provided. Antipsychotic medications exert their therapeutic effects by blocking dopamine receptors, particularly the \(D_2\) receptors. Risperidone's strong affinity for these receptors makes it a potent antipsychotic agent. The other options, A) Clozapine, B) Olanzapine, and C) Quetiapine, are atypical antipsychotic agents that have varying receptor affinities and pharmacological profiles. While these medications also block dopamine receptors, their affinity for the \(D_2\) receptors is lower compared to risperidone. Clozapine, for example, has a higher affinity for other receptors like muscarinic and histamine receptors, contributing to its unique side effect profile. In an educational context, understanding the pharmacological properties of antipsychotic medications is crucial for healthcare professionals managing patients with schizophrenia. Knowing the receptor affinities of different antipsychotics helps tailor treatment based on individual patient characteristics and provides insight into potential side effects and efficacy. This knowledge enhances clinical decision-making and promotes safe and effective medication management in psychiatric practice.

Correct Answer: A

Rationale: NSAIDs, such as ibuprofen, aspirin, and naproxen, share a side effect profile linked to their inhibition of COX enzymes, which reduces protective prostaglandins. Gastrointestinal ulceration occurs due to decreased mucus production in the stomach, increasing risks of bleeding or ulcers, a well-known issue with chronic use. Nephropathy results from reduced renal prostaglandin synthesis, impairing kidney perfusion and potentially leading to acute or chronic renal damage. Hepatotoxicity, though less frequent, can arise from metabolic overload in the liver with prolonged high doses. Addiction, however, is not associated with NSAIDs. It's a characteristic of opioids, which stimulate the brain's reward pathways via mu receptors, fostering dependence. NSAIDs lack psychoactive properties and don't induce euphoria or craving, making Addiction the exception. This question tests the ability to differentiate NSAID toxicities from those of other drug classes, vital for safe prescribing and patient counseling on risks.

Correct Answer: C

Rationale: Nalbuphine (choice C), a mixed agonist-antagonist (kappa agonist, mu antagonist), can precipitate withdrawal in morphine addicts by antagonizing mu receptors, displacing morphine and reversing its effects, causing symptoms like anxiety and sweating. Meperidine (choice A), Methadone (choice B), and Fentanyl (choice D), all full mu agonists, maintain opioid effects, not inducing withdrawal unless stopped abruptly. Nalbuphine's antagonistic action at mu receptors in dependent patients makes it the correct choice. This highlights the importance of receptor pharmacology in managing opioid-dependent patients, avoiding unintended withdrawal.