Hi! Thank you for your question. The way you've been doing it is perfectly fine, and you are free to assume hospital visits or anything else he needs. Healthcare is free in Riverview, and they are definitely able to synthesize and create medicines to help him out.

Essentially, you can feel free to play with this in a way that would be enjoyable for you - they could keep him stable with the medicine he is currently using, they could attempt to improve on the medicine he's using and find something better, or try to cure his illness and fail (since you said you would like to keep it), with varying results. All of this is up to you, and what would be fun for you to play with!