Metronidazole-Induced Irreversible Optic Neuropathy

Area of Science:

• Neuro-ophthalmology
• Neurology

Background:

• Metronidazole is an antibiotic commonly used for anaerobic bacterial and protozoal infections.
• Optic neuropathy is a known, albeit rare, adverse effect of metronidazole treatment.
• Most reported cases exhibit good visual recovery after drug discontinuation.

Observation:

• A patient developed sudden, severe visual loss after a one-week course of metronidazole.
• Simultaneously, the patient experienced myelitis, a neurological deficit affecting the spinal cord.
• Despite immediate cessation of metronidazole and initiation of various treatments, no improvement in vision or neurological function was observed.

Findings:

• This case presents a severe, treatment-refractory presentation of metronidazole-induced optic neuropathy.
• The co-occurrence of myelitis suggests a potential broader neurotoxic effect of metronidazole.
• The lack of response to treatment challenges the typical prognosis of excellent visual recovery.

Implications:

• This case underscores the potential for severe neurotoxicity from metronidazole, even with prompt management.
• It highlights the importance of considering metronidazole as a potential cause of optic neuropathy and myelitis in clinical practice.
• Further research is needed to understand the mechanisms and identify risk factors for severe, non-resolving cases.