After using antibiotics there can be a tongue infection with Candida albicans a yeast infection. These medications can cause thrush by allowing the fungus to overgrow on the tongue. An oral thrush infection scrapes off and leaves a reddened area compared to a white coating from buildup of dead skin cells on the tongue when scraped with a tongue depressor .It is best to see a doctor and get the diagnosis confirmed. Treatment will be specific based on the cause. Keep me posted.
Best luck and regards!
Yes, could be candida, best cure : try ozonated water. It kills bugs and also candida