A gardener needs a decongestant because of seasonal allergy problems and asks the nurse whether he should take an oral form or a nasal spray. The nurse’s answer considers that one benefit of orally administered decongestants is

Correct Answer: C

Rationale: The correct answer is C: lack of rebound congestion. Orally administered decongestants are less likely to cause rebound congestion compared to nasal sprays. This is because oral decongestants work systemically, targeting the whole body, whereas nasal sprays work locally, leading to potential rebound congestion when discontinued. Immediate onset (A) and potent effect (B) are not specific benefits of oral decongestants. Shorter duration (D) is also not a distinctive benefit of oral decongestants.

Correct Answer: B

Rationale: The correct definition of a toxic dose is B: The amount of substance to produce effects hazardous for an organism. This is because a toxic dose refers to the quantity of a substance that can cause harm or adverse effects to an organism. It is important to differentiate between toxic doses and other types of doses, such as therapeutic doses (choice C) which produce the desired effect without causing harm. Choices A and D are incorrect as they do not accurately describe a toxic dose and are not related to the harmful effects of a substance on an organism.

Correct Answer: C

Rationale: Step-by-step rationale: 1. The anesthetic effect of short and intermediate duration agents is primarily influenced by their metabolism and distribution in the body. 2. Dopamine is not commonly used to prolong anesthesia as it primarily acts as a neurotransmitter and vasopressor. 3. Epinephrine, norepinephrine, and phenylephrine are commonly used to prolong anesthesia due to their vasoconstrictive properties. 4. Therefore, the correct answer is C (Dopamine) as it does not have the same vasoconstrictive effects as the other choices.

Correct Answer: C

Rationale: Correct Answer: C (Pralidoxime) Rationale: 1. Pralidoxime reactivates inhibited cholinesterase enzymes. 2. This helps counteract the toxic effects of organophosphate cholinesterase inhibitors. 3. Atropine is used to treat the symptoms but does not directly counteract the toxic effects. 4. Pilocarpine and edrophonium are not used for acute toxic effects of organophosphate poisoning.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Succinylcholine causes transient muscle fasciculations due to its depolarizing mechanism of action. 2. It binds to nicotinic acetylcholine receptors, causing initial muscle twitching. 3. This fasciculation phase is a distinct feature of succinylcholine. 4. Mivacurium, Pancuronium, and Tubocurarine are non-depolarizing blockers, so they do not cause initial muscle fasciculations. Summary: A, B, and D are incorrect because they are non-depolarizing blockers and do not induce muscle fasciculations like succinylcholine.