Which of the following inhaled anesthetics has rapid onset and recovery?

Correct Answer: D

Rationale: The correct answer is D: All of the above. Nitrous oxide, Desflurane, and Sevoflurane are all inhaled anesthetics known for their rapid onset and recovery. Nitrous oxide is rapid due to its low blood-gas solubility, while Desflurane and Sevoflurane are quick-acting because of their low solubility and fast elimination from the body. Therefore, all three options meet the criteria of having rapid onset and recovery. The other choices are incorrect because they do not fully encompass all the anesthetics that exhibit these characteristics.

Correct Answer: B

Rationale: Step 1: Heparin is a medication with poor oral bioavailability, meaning it is not effectively absorbed when taken orally. Step 2: For heparin to be effective, it needs to be administered via injection or infusion to reach therapeutic levels. Step 3: Therefore, the statement that heparin is effective when administered orally is false. Summary: Choice B is correct because heparin's efficacy is not achieved through oral administration. Choices A, C, and D are incorrect because they do not acknowledge the pharmacokinetics of heparin.

Correct Answer: C

Rationale: Rationale: Lidocaine is the drug of choice for acute treatment of ventricular tachycardias due to its fast onset of action and minimal negative inotropic effects. It works by stabilizing cell membranes and reducing automaticity in the ventricular tissue. Flecainide (A) and Sotalol (B) are contraindicated in ventricular tachycardias due to their potential to worsen arrhythmias. Verapamil (D) is a calcium channel blocker and is not effective for treating ventricular tachycardias.

Correct Answer: A

Rationale: The correct answer is A: Propranolol. Propranolol is a beta-blocker that inhibits renin synthesis by blocking beta-1 adrenergic receptors in the juxtaglomerular cells of the kidney. This leads to decreased renin release and ultimately reduces the production of angiotensin II. Enalapril (B) is an ACE inhibitor that acts downstream by inhibiting the conversion of angiotensin I to angiotensin II. Diazoxide (C) is a potassium channel activator and Losartan (D) is an angiotensin II receptor blocker, both of which do not directly inhibit renin synthesis.

Correct Answer: D

Rationale: The correct answer is D because hormone analogues are synthetic compounds that mimic the structure and function of naturally occurring hormones. This is important for therapeutic purposes as they can be used to replace or mimic the actions of hormones in the body. A is incorrect because hormone analogues are not naturally occurring substances but rather synthetic compounds. B is incorrect as hormone analogues can be equally or even more efficacious than naturally occurring hormones. C is incorrect because although hormone analogues may have similar structures to hormones, they do not necessarily have the same pharmacological properties.