You can do the typical why is Ritalin a stimulant yet calms down ADD [dysregulation of firing becomes normalized] normal + drug = excess = excited, Add + drug = bring to normal = calm..
One thing about Parkinson's is there's a few straightforward therapies, but you can play with them. And perhaps outlining a few cases highlighting how therapies differ. Few interesting scenarios:
Selegiline is initiated in younger persons <65 displaying Parkinson's symptoms for its neuroprotective effects: blocking MAO stops DA metabolism, thereby stopping free radical production; but often not initiated in those older patients.
Trihexyphenidyl[anticholinergic] given in younger persons when tremor is the predominant symptom... could get into why it influences tremor more than another initial therapy, like amantadine. Amantadine inhibits DA metabolism and has anticholinergic effects.
DA agonists are good -> dopamine dysregulation syndrome. uncommon but prevalent syndrome of excessive gambling, hypersexuality, punding, etc. in individuals on DA agonists like ropinerole. Very very interesting phenomenon. Also excess somnolence, occasionally "sleep attacks". DA agonists prolong development of dopament dyskinesias... very impt. Dyskinesias develop in those on the typical Sinemet about 3-5 years after starting therapy, DA agonists delay the development of these and are often given before sinemet in younger indviduals for this reason.
Also, some neurologists tell pts to crack their Sinemet CR in half for their morning dose, that way they get the quick initial control of a regular release with some prolonged action of a CR. Interesting strategy to control blood levels.
Since its 45 mins there are a few areas for you to play with there, how one drug is chosen over the other, the interesting side effects [hallucinations, etc], etc.
