Depends on how much you took. But to be on the safe side, don't drink.
The major drug/drug interaction is between the benadryl and alcohol. Both are CNS depressants; the combination can produce a higher than "added" effect and varies considerably by individuals.
[url="http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682539.html"]http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682539.html[/url]
You should also avoid any grapefruit [incl. juice] since grapefruit enhances the potency of drugs that use a particular liver pathway from 40% to 1500%.