Levodopa/carbidopa (most commonly known as Sinemet®) is the first-line and most effective treatment for Parkinson’s disease. Levodopa is converted into dopamine in the brain, improving movement symptoms such as tremor, stiffness, and slowness. Carbidopa is included to prevent levodopa from breaking down before reaching the brain and to reduce side effects like nausea and vomiting. The combination provides significant symptom relief, especially in the early years of treatment. Over time, however, patients may experience motor fluctuations (wearing-off, on-off periods) and dyskinesias, requiring careful dose adjustments or additional therapies.