DD is 5 and has had a ear infection in one, then both ears for just over 3 weeks.
Amoxicillin was ineffective so GP tried erythromycin. That didn't do the trick, so a stronger dose of amoxicillin was given.
We have stuck to the regime, given calpol and neurofen. The very last dose was this morning. 
She's up now with earache, poor mite, so back to GP in the morning.