A 62-year-old man from Delhi presents with a 3-year history of progressive slowness of movement and tremor in his right hand at rest. On examination, he has a masked facies, cogwheel rigidity in both upper limbs, and a shuffling gait with reduced arm swing. His Mini-Cog score is 4/5. He is currently on no medications. Which of the following is the most appropriate first-line pharmacological agent to initiate in this patient?

Explanation

## Clinical Presentation Analysis This patient presents with the cardinal features of Parkinson disease: - **Resting tremor** (right hand) - **Bradykinesia** (slowness of movement) - **Rigidity** (cogwheel pattern) - **Postural abnormality** (shuffling gait, reduced arm swing) - **Hypokinetic facies** (masked facies) ## First-Line Therapy in Early PD **Key Point:** In younger patients (age <70 years) with early-stage PD and preserved cognition, dopamine agonist monotherapy is preferred as first-line to delay levodopa-induced motor complications (dyskinesias, motor fluctuations). **High-Yield:** The choice of initial agent depends on: 1. **Age at onset** 2. **Presence of cognitive impairment** 3. **Risk of motor complications** | Agent | First-Line Use | Rationale | |-------|---|---| | Dopamine agonist (ropinirole, pramipexole) | Age <70, early PD, intact cognition | Delays levodopa-related dyskinesias; motor complications less frequent | | Levodopa + inhibitor | Age >70 OR advanced PD OR cognitive decline | Most potent; used when agonists fail or cognition impaired | | Selegiline | Adjunctive only | Weak monotherapy; used as add-on in early disease | | Amantadine | Adjunctive only | Used for dyskinesias or rigidity; not first-line monotherapy | ## Why Ropinirole? **Clinical Pearl:** This 62-year-old patient with: - Early-stage disease (3 years) - Intact cognition (Mini-Cog 4/5) - No prior dopaminergic therapy ...is an ideal candidate for dopamine agonist monotherapy. Ropinirole (or pramipexole) reduces the risk of motor complications compared to early levodopa initiation [cite:Harrison 21e Ch 451]. **Mnemonic for PD drug selection:** **LADS** = **L**evodopa (age >70 or advanced), **A**gonist (age <70 early), **D**elay complications, **S**elegiline (adjunct). ## Mechanism Ropinirole is a non-ergot D2/D3 dopamine agonist that: 1. Directly stimulates dopamine receptors in the striatum 2. Provides symptomatic relief without the long-term dyskinesia risk of levodopa 3. Can be titrated gradually to minimize side effects