AND, just to muddy the waters even more (because who really needs 100 foot vis anyway?), there isn't a lot of evidence that any oral medication helps with chronic Eustachian tube dysfunction.
Guidelines from the AAP, AAFP and AAO-HNS, see numbers 5 and 11 particularly
There is a lot of anecdotal evidence that systemic (oral) decongestants will help if you are diving and get an acute upper respiratory tract infection, or that antihistamines will help if your allergies are acting up. And systemic steroids will also help in acute cases, but are generally avoided due to side effects.
Nasal decongestants (e.g. Afrin) help with sinus equalization but not so much with the Eustachian tube, which is way in the back of the nose. Afrin only touches one end of it, if at all. But it is GREAT for avoiding sinus squeeze - just remember not to use it for more than three days, you can get addicted..
Nasal steroids take about a week to work, and are mainly for allergic nasal congestion.
But of course, TSandM and Doc Vikingo are correct that in certain circumstances, each of these drugs does have a place. However, most people can clear their ears with practice and the use of one or more equalization techniques...