There is no such thing as strong or weak antibiotic. Just appropriate as has already been commented. Don't take any advice from any of the "experts" here, however well meant. Infections can be very different, i.e. have a different cause. Only a culture and assessment can help to choose the right antibiotic. There are wide-spectrum antibiotics that are effective against many microorganisms, but there is the risk of creating resistance. Antibiotics are grossly misused in this part of the world anyway, so seek the advice of a prudent doctor who can explain why you should have antibiotics and which kind. And they don't work against for instance a fungus. Says this MD.
And by the way, this kind of topic should be removed, some advice is just dangerous.