What causes swollen gums and lesions in the mouth after taking Metronidazole?
Aphtous ulcer, supportive care
Thank you for asking at Ehealth forum!
I read your question and i understand your concern. Yes flagyl can cause oral cavity lesions and bad taste. Aphthous ulcer is one of the possible complication. It could be due to gastric discomfort. No matter what, it self resolves, just apply some topical anesthetic and hydrocortisone gel over it for relief and keep good oral hygiene and stay hydrated. It shall resolve in a couple of days.
I hope it helps. Stay in touch with your healthcare provider for further guidance as our answers are just for education and counselling purposes and cannot be an alternative to actual visit to a doctor.