I've looked at a young chap (well, 66, so young to my mind) who unfortunately has Parkinson's Disease (PD). He's under the care of a physician who's been grappling with his PD but found the psychotic features tricky to manage, so asked for my views.
In PD there're regions of the brain where there is not enough dopamine. Result : my chap's rigid, literally unable to initiate movement and struggling to initiate speech and action. Medication is given to boost dopamine, helping improve the symptoms of his PD so he can play pool, read his paper, walk to the shops with his wife. Much better.
An unhappy side effect of the treatment is that the neuropsychiatric sequelae of PD become more prominent. That's to say, he has hallucinations and delusions. He awoke to see animals on his bed at 3.00am and had to get up, causing difficulties on the ward. This was compounded by his conviction that his wife had died and he had to get to her (so attempted to climb out of a window to leave the ward). Charging round a geriatric ward at 3.00am and making escapes unsettles staff, hence a referral to me.
I can start using an effective antipsychotic to help with his hallucinations and delusions. These types of medicine effectively reduce dopamine levels in the brain, improving his mental health. Result : his psychotic experiences (the hallucinations and delusions) improve but the dopamine antagonism works against his PD medication and his PD gets worse.
One antipsychotic, quetiapine, can work well . . . I've tried this but it's sedating him excessively so isn't an option.
Clozapine can also help, but is also very sedating (and can stop your body making blood cells to fight off infection, which kills you, and rarely you can get serious heart damage, which kills you). You need frequent (initially weekly) blood tests while you take clozapine and then ongoing blood tests at regular intervals since it's so hairy. Given his sensitivity to sedation I don't see him tolerating clozapine but it can be tried.
He's too unwell to be able to communicate preferences or discuss treatment options meaningfully and proffer valid consent. His wife obviously can't consent for him but I sought her opinion and she's keen for me to do "what ever is best" for him.
So what to do?
Either he's physically locked in (as his PD is bad) and mentally better (as his psychotic symptoms are managed). Or he's physically well and active (as his PD is well managed) and mentally unwell (with intense intrusive psychotic symptoms).