Which of the following statements regarding drugs of abuse is true?

Correct Answer: B

Rationale: The correct answer is B) LSD acts on various 5-HT receptors to produce its effects. This statement is true because LSD, or lysergic acid diethylamide, is a hallucinogenic drug that primarily exerts its effects by interacting with serotonin (5-HT) receptors in the brain. This interaction leads to alterations in perception, mood, and cognition. Option A is incorrect because ketamine is actually a dissociative anesthetic that is structurally related to PCP (phencyclidine), not psilocybin which is a hallucinogenic compound found in certain mushrooms. Option C is incorrect because marijuana, or cannabis, typically causes miosis (pupillary constriction) rather than mydriasis (pupillary dilation) and conjunctival injection (red eyes) due to its effects on the endocannabinoid system. Option D is incorrect because cocaine is a short-acting stimulant drug with a relatively short plasma half-life, typically around 1 hour. Its rapid metabolism and elimination contribute to its short duration of action. Educationally, understanding the pharmacological actions of drugs of abuse is crucial for healthcare professionals to recognize their effects, potential interactions, and implications for patient care. By knowing how these substances work, nurses can better assess, educate, and support individuals struggling with substance abuse disorders.

Correct Answer: A

Rationale: The correct answer is A) Receptor blockers have anticonvulsant activity. This statement is false because GABA receptor blockers actually decrease the inhibitory effects of GABA, leading to increased neuronal excitability. Anticonvulsant activity is typically associated with drugs that enhance GABAergic transmission, not block it. Option B) Is found in high concentrations in the basal ganglia is true. GABA is indeed found in high concentrations in the basal ganglia, where it plays a crucial role in motor control and movement regulation. Option C) Concentrations in the basal ganglia are abnormally low in Huntington's chorea is also true. In Huntington's chorea, there is a decrease in GABA levels in the basal ganglia, contributing to the motor symptoms seen in this condition. Option D) Metabolism is inhibited by sodium valproate is true. Sodium valproate is known to inhibit the metabolism of GABA, leading to increased levels of this neurotransmitter in the brain. Educationally, understanding the role of GABA in the central nervous system is crucial for healthcare professionals, especially when managing conditions like epilepsy, movement disorders, and mood disorders. Knowing how drugs affect GABAergic transmission can help in selecting appropriate treatment options and understanding the underlying mechanisms of various neurological conditions.

Correct Answer: A

Rationale: The correct answer is A) Atropine. Pilocarpine is a parasympathomimetic drug that causes miosis (pupillary constriction) by stimulating the cholinergic receptors in the eye. In this scenario, the patient has received an overdose of pilocarpine, leading to excessive miosis, which can result in symptoms like blurred vision, headache, and brow ache. Atropine, an anticholinergic medication, is the antidote for pilocarpine overdose. It works by blocking the effects of excessive acetylcholine, thereby reversing the miosis and alleviating the symptoms. Option B) Carbachol is another cholinergic agonist, so administering it would exacerbate the effects of pilocarpine overdose. Options C) Donepezil and D) Galantamine are both acetylcholinesterase inhibitors used in Alzheimer's disease to increase acetylcholine levels in the brain. However, they do not reverse the effects of excessive cholinergic stimulation in the eye caused by pilocarpine overdose. In an educational context, understanding the pharmacological properties of drugs is crucial for healthcare professionals to provide safe and effective patient care. Knowing the antidotes for drug overdoses and adverse effects is essential in emergency situations to prevent further harm to the patient. This scenario highlights the importance of medication administration accuracy and the need for quick intervention when errors occur.

Correct Answer: D

Rationale: In this scenario, the correct answer is D) Tamsulosin. Tamsulosin is a selective alpha-1 blocker that specifically targets the alpha-1 receptors in the prostate, leading to relaxation of smooth muscle in the bladder neck and prostate, which helps improve urinary flow and reduce symptoms of benign prostatic hyperplasia (BPH) like a weak stream and nocturia. A) Alfuzosin, B) Doxazosin, and C) Prazosin are also alpha-1 blockers used in BPH treatment, but they are less selective for the alpha-1 receptors in the prostate compared to Tamsulosin. This reduced selectivity can lead to more side effects like dizziness, low blood pressure, and fatigue, which the patient in this case wants to avoid due to sensitivity to medication side effects. Educationally, this question assesses the candidate's understanding of the pharmacological treatment of BPH and the importance of selecting medications with specific receptor selectivity to minimize side effects, especially in elderly patients who may be more prone to adverse reactions. Understanding the rationale behind choosing Tamsulosin over other alpha-1 blockers reinforces the importance of individualizing treatment based on a patient's specific needs and characteristics.

Correct Answer: C

Rationale: The correct answer is C) Retroperitoneal fibrosis. In this scenario, the patient's bilateral hydronephrosis and elevated serum creatinine are most likely due to retroperitoneal fibrosis caused by the bromocriptine. Retroperitoneal fibrosis is a known adverse effect of bromocriptine, a central nervous system stimulant used in Parkinson's disease. This condition results from the development of fibrous tissue in the retroperitoneal space, leading to compression of nearby structures, including the ureters, causing hydronephrosis and renal impairment. Option A) Drug toxicity is not the best choice because it does not specifically address the mechanism of action leading to the renal findings in this case. Renal artery stenosis (Option B) and renal vein thrombosis (Option D) are less likely as they typically present with different clinical features and are not commonly associated with bromocriptine use in Parkinson's disease. Educationally, understanding the potential side effects and adverse reactions of medications used in neurological conditions like Parkinson's disease is crucial for healthcare professionals. This case highlights the importance of monitoring patients for rare but serious complications associated with central nervous system stimulants, ensuring early detection and management to prevent significant harm.