This page from European Urology is enlightening for anyone treating urinary urgency or taking the treatments. The text explains that oral treatments’ beneficial responses are slight, modest and substantially placebo effects at the cost of over twice the risk of inducing cognitive impairments.
They also produce symptomatic side effects, most notably dry mouth, that are real and mechanistically well understood as antimuscarinic actions on tissue receptors.
The authors explain that any benefits arise through actions on bladder mucosa.
If the drugs were instilled into the bladder directly, then the benefits should be achieved without producing symptomatic or adverse side effects, such as unquenchable dry mouth thirst, because of their limited systemic absorption through urothelium.
I wonder how many elderly people have been transferred into nursing care because we treat urinary urgency with tablets.
It is time we all seriously consider direct-target treatment for bladder diseases and disorders such as urinary urgency. The sooner such products are available under licence, the better.