In the assessment of Parkinson's disease, which medication is considered a first-line treatment?

Levodopa is considered a first-line treatment for Parkinson's disease due to its effectiveness in managing the hallmark motor symptoms associated with the condition. It works by converting to dopamine in the brain, which compensates for the decreased levels of dopamine caused by the degeneration of dopaminergic neurons in the substantia nigra. This treatment significantly improves symptoms such as bradykinesia, rigidity, and tremor.

The preference for levodopa over other medications stems from its direct action on the primary neurotransmitter that is deficient in Parkinson's disease. While other medications can play a role in the overall management of the disease, they are either used in conjunction with levodopa as adjunct therapies or for different indications altogether.

For instance, baclofen is a muscle relaxant that may be used for muscle spasticity, but it does not address the specific dopamine deficit in Parkinson's disease. Gabapentin is primarily used for neuropathic pain and seizures and does not have a role in treating Parkinson's. Donepezil is an acetylcholinesterase inhibitor used mainly for Alzheimer’s disease and has no established benefit for the motor symptoms of Parkinson's. Hence, levodopa remains the cornerstone of Parkinson’s disease treatment for its direct influence on the