Is a black hairy tongue common with antibiotics?

Fungal superinfectio: Not very common but it does happen in some individuals.Antibiotics tend to suppress bacterias, & hence fungus tends to overgrow. consult your physician who presribed the antibiotics & may be he can put you on additional antifungal medication or if you do not need antibiotics anymore,he may decide to stop antibiotics. Keeping immaculate oral hygiene would also help.

Yes, it is possible: The poor oral hygiene, extensive use of antibiotics, excessive tea drinking and tobacco use are the most common causes of hairy tongue.

Black hairy tongue: Black hairy tongue can occur when you take antibiotics because the normal bacteria in the mouth is killed off. Clean your tongue with a tongue scraper or toothbrush. This should resolve once you finish the antibiotic.

Relatively common: Antibiotics associated with black hairy tongue are relatively common. It is a benign, self-limiting disorder. Eliminating any causative factors and adequate oral hygiene will cure benign hairy tongue.