you know i just had to look.

good grief!

anyway, i am guessing a reason these drugs can potentially cause gum overdevelopment is that they can all cause dry mouth. anything that reduces flow of saliva in the mouth can impact gum health. one thing that can be done to alleviate this somewhat is to suck hard, sugar-free (for teeth) candy or otherwise hydrate the mouth regularly.

there is perhaps more to it than that though, because a great many other drugs cause dry mouth but the Wiki article singles out these 3 drug classes.

~ waves ~