Ketamine is a general anaesthetic that can be administered by

Correct Answer: C

Rationale: The correct answer is C because ketamine can be administered via both intravenous and intramuscular routes. Intravenous administration allows for rapid onset of action, making it ideal for induction of anesthesia. Intramuscular administration provides an alternative option for administration when intravenous access is not available. Options A and B are incorrect because ketamine can be administered via both routes. Option D is incorrect as ketamine can be administered through one or both of the mentioned routes.

Correct Answer: C

Rationale: An inverse agonist is a compound that binds to the same receptor as an agonist but induces the opposite effect by decreasing the basal activity of the receptor. Beta-Carboline is the correct answer as it acts as an inverse agonist at GABA-A receptors, reducing the inhibitory effect of GABA. A: Buspirone is a partial agonist at serotonin receptors, not an inverse agonist. B: Flumazenil is a benzodiazepine receptor antagonist, not an inverse agonist. D: Zolpidem is a positive allosteric modulator of GABA-A receptors, not an inverse agonist. Summary: Beta-Carboline is the only choice that fits the definition of an inverse agonist by reducing receptor activity, making it the correct answer.

Correct Answer: A

Rationale: Carbamazepine is related to tricyclic antidepressants due to its chemical structure containing a tricyclic ring system. This similarity allows carbamazepine to exhibit similar pharmacological effects and mechanisms of action as tricyclic antidepressants. On the other hand, barbiturates, benzodiazepines, and MAOIs have different chemical structures and mechanisms of action compared to carbamazepine, making them incorrect choices.

Correct Answer: D

Rationale: The correct answer is D because the volume of distribution (Vd) is a pharmacokinetic parameter that relates the amount of a drug in the body to the concentration of the drug in plasma. It is a theoretical volume that indicates how extensively a drug distributes into body tissues in relation to its plasma concentration. Vd is a crucial parameter in determining the loading dose of a drug and its distribution characteristics. Explanation for why the other choices are incorrect: A: An administered dose to body weight is related to dosing calculations but not specifically to Vd. B: Single to daily dose of an administered drug is related to dosing frequency, not Vd. C: An uncharged drug reaching the systemic circulation does not directly relate to Vd, which pertains to the drug's distribution in the body.

Correct Answer: B

Rationale: First-order kinetics means the rate of drug elimination is proportional to its concentration. Clearance value (correct answer B) remains constant because it represents the volume of blood from which the drug is completely removed per unit time. Choice A is incorrect because the amount eliminated per unit time decreases as the drug concentration decreases. Choice C is incorrect as elimination half-life remains constant regardless of the dose. Choice D is incorrect because it takes approximately 4-5 half-lives for a drug to be considered completely eliminated, not just 2.