Introduction:
Metronidazole is a bactericidal, amoebicidal, and trichomonacidal agent
targeting anaerobic bacteria, certain amoebic and protozoal species. It
is a nitroimidazole that inhibits nucleic acid synthesis by disrupting
DNA resulting in strand breakage. Its bioavailability is more than 80%
when taken orally. It is a usually well-tolerated antimicrobial but can
cause gastrointestinal side effects like a gastric upset in the form of
nausea, vomiting, abdominal cramps, diarrhea, or constipation [1].
It has also been associated with other adverse effects like dizziness,
darkening of the urine, and joint pain. Disulfiram reaction has been
reported, especially in those drinking ethanol. Neuro-ophthalmologic
side effects such as peripheral neuropathy, ataxia, encephalopathy, and
even seizures have been reported with metronidazole use[2]. Optic
neuritis, an inflammation of the optic nerve, is an unrecognized side
effect of Metronidazole and has been reported in association with
metronidazole administration in a few case reports. The nerve damage
induced by Metronidazole can be either temporary or permanent.
Here, we are reporting a 30-year-old lady who had a bout of
gastroenteritis and was given a dose of IV Metronidazole and one day
after which she started noticing decreased right eye vision, which
progressed to complete vision loss in her right eye. She was managed
with IV Pulse steroids. She showed a slight improvement in her right
eyesight.