Most antibiotics prescribed by dentists, i.e., penicillin, cephalosporins, amoxicillin, clavulanic acid, erythromycin (base) and clindamycin are category B drugs and are safe to prescribe during pregnancy and lactation. Tetracycline and its derivatives, i.e., doxycycline, are in category D because of their effects on developing bones and teeth should be avoided. Ciprofloxacin, used in treating periodontal disease, is in category C because of arthropathy and adverse effects on cartilage development observed in immature mice. However, there is insufficient data from studies to determine safety in humans. Metronidizole, used to treat pericoronitis or acute necrotizing gingivitis, is in category B. However, the obstetrician should be consulted before prescribing this drug to determine the risk/benefit to the patient because of some reports of midline facial defects in humans and carcinogenic effects in rodents. The estolate form of erythromycin should be avoided because of deleterious effects on the mother's liver. The antimicrobial rinse, chlorhexidine gluconate, is in category B and has shown no adverse effects in pregnancy or lactation.
Nystatin rinse is in category B and safe for treatment of oral fungal infections during pregnancy or lactation. Fluconazole and ketoconazole are in category C and should be avoided if possible as their effects during lactation are unknown.