Many times ear infections that are resistant to antibiotics can be cleared up by slightly warming a vinegar and water mixture and flushing the ear two or three times with the mixture twice a day with an ear flush bulb.
An herbal formula does a good job also by Nature’s Sunshine. Here’s a link: http://www.theherbsplace.com/cbgext.html
My son had a terrible problem with this. A doctor told me to crush a clove of garlic in a little olive oil, warm it up to about the temperature of a baby bottle, strain out the garlic, put a couple drops in with an eye dropper, & put cotton in the ear. The garlic helped clear up the infection, and the olive oil soothed the pain. Still use it 18 years later.