## Core Concept
The question tests knowledge of drug-induced pericarditis, a condition where certain medications can cause inflammation of the pericardium, the sac surrounding the heart. This condition can lead to chest pain and other cardiac complications. Various drugs have been associated with pericarditis as an adverse effect.

## Why the Correct Answer is Right
To answer this question correctly, one needs to identify which of the listed drugs is least likely or not associated with causing pericarditis.

## Why Each Wrong Option is Incorrect
- **Option A: Methysergide** - Methysergide is known to cause fibrotic reactions, including retroperitoneal fibrosis, but it's less commonly associated directly with pericarditis compared to others.
- **Option B: Hydralazine** - Hydralazine, a drug used to treat hypertension, is known to cause a lupus-like syndrome and has been associated with pericarditis.
- **Option C: Amiodarone** - Amiodarone, an antiarrhythmic medication, can cause a range of cardiac side effects, including pulmonary fibrosis and, less commonly, pericarditis.
- **Option E: Minoxidil** - Minoxidil, another antihypertensive drug, has been associated with pericardial effusion and pericarditis.

## Clinical Pearl / High-Yield Fact
A notable association is with **Hydralazine** and **Procainamide**, which can cause drug-induced lupus and are known to have cardiac side effects including pericarditis. Among the given options, **Bretylium** is actually used for its antiarrhythmic properties and has been associated with pericarditis; however, **Methysergide** stands out as it's more famously linked to fibrotic reactions.

## Correct Answer Line
**Correct Answer: A. Methysergide**