**Question:** Figure B shows the following medication concentrations over time.

A. 500 mg oral prednisolone
B. 25 mg oral prednisolone
C. 100 mg oral methylprednisolone
D. 5 mg intravenous methylprednisolone

**Correct Answer:** D. 5 mg intravenous methylprednisolone

**Core Concept:** Prednisolone and methylprednisolone are corticosteroids, a class of medications used for their anti-inflammatory, immunosuppressive, and anti-allergic effects. They are used to treat various conditions like asthma, autoimmune disorders, and transplant rejection. Both prednisolone and methylprednisolone are glucocorticoids, which interact with glucocorticoid receptors and inhibit phospholipase A2, thus suppressing arachidonic acid cascade and reducing inflammation.

**Why the Correct Answer is Right:** Methylprednisolone is a more potent corticosteroid than prednisolone, meaning it has a higher affinity for glucocorticoid receptors and a stronger anti-inflammatory effect. This is due to its longer half-life, allowing for fewer administrations and potentially reducing the risk of side effects associated with frequent administration of prednisolone. In this MCQ, option D represents a 5 mg dose of intravenous methylprednisolone, which is a higher dose compared to options A, B, and C.

**Why Each Wrong Option is Incorrect:**

A. 500 mg oral prednisolone: Prednisolone is less potent than methylprednisolone, resulting in higher doses being required for therapeutic effect. Option A represents an oral dose of prednisolone, which is less potent and may require multiple daily administrations.

B. 25 mg oral prednisolone: Similar to option A, oral prednisolone is less potent than methylprednisolone, making it less effective at the given dose. Additionally, oral administration may lead to variable bioavailability and absorption compared to intravenous administration (option D).

C. 100 mg oral methylprednisolone: Methylprednisolone is more potent than prednisolone, requiring lower doses for therapeutic effect. However, oral administration (option C) may lead to variable bioavailability and absorption compared to intravenous administration (option D).

**Clinical Pearl:** The choice of corticosteroid and its administration route depends on the patient's condition, severity, and response to treatment. Dosing and route of administration should be tailored to the patient's needs to optimize therapeutic outcomes and minimize side effects.