Side Effects of Ornidazole
Ornidazole can cause various side effects ranging from common gastrointestinal symptoms to rare but serious neurological complications, with the most frequently reported side effects being headache and nausea. 1
Common Side Effects
- Gastrointestinal effects: Nausea, vomiting, diarrhea, and gastritis are commonly reported 1, 2
- Metallic taste in the mouth occurs in approximately 5.85% of patients 2
- Headache is one of the most frequently reported side effects 1, 3
Serious Side Effects
Neurological Complications
- Encephalopathy: Characterized by unsteady gait, slurred speech, and psychiatric disorders. This is a rare but serious complication that can occur with prolonged use 4
- Cerebellar ataxia and dysarthria: These symptoms typically resolve after drug discontinuation 4
- Mental symptoms: Including agitation and irritability have been reported 4
Hepatotoxicity
- Acute cholestatic hepatitis: A rare but documented side effect that can develop even with conventional doses 5
- Liver damage: Characterized by elevated liver enzymes, which typically improves 1-2 months after discontinuation of the drug 5
Risk Factors and Considerations
- Duration of treatment: Long-term use (years) increases the risk of neurological complications 4
- Dosage: Higher doses may increase the likelihood of side effects 3
- Concurrent medications: Potential interactions should be monitored, especially with drugs metabolized by cytochrome P450 enzymes 6
Monitoring Recommendations
- Liver function tests: Should be considered for patients on prolonged therapy due to potential hepatotoxicity 5
- Neurological assessment: For patients reporting symptoms like unsteady gait, slurred speech, or mental status changes 4
- Regular clinical evaluation: To assess for common side effects like nausea, headache, and gastrointestinal disturbances 1, 2
Management of Side Effects
- Discontinuation: For serious side effects like encephalopathy or hepatotoxicity, immediate discontinuation of ornidazole is recommended 4, 5
- Supportive care: For management of gastrointestinal symptoms 2
- Follow-up imaging: In cases of neurological complications, follow-up MRI may be warranted to confirm resolution of brain lesions 4
Special Considerations
- Reversibility: Most side effects, including neurological complications and hepatotoxicity, appear to be reversible upon discontinuation of the drug 4, 5
- Time to resolution: Neurological symptoms typically improve within 3-4 days after stopping the medication, while hepatic effects may take 1-2 months to resolve 4, 5