Entacapone Impurities

• Monitor for dyskinesia (uncontrolled movements) – May increase levodopa’s effects.
• Avoid sudden discontinuation – Stopping entacapone abruptly can worsen Parkinson’s symptoms.
• Use caution in patients with heart disease – May cause blood pressure changes.
• May cause dizziness or drowsiness – Avoid driving or operating machinery if affected.

• Liver function tests (LFTs) – To detect potential liver toxicity.
• Blood pressure – Can cause orthostatic hypotension (sudden drops in blood pressure).
• Neurological symptoms – Watch for hallucinations, confusion, or increased dyskinesia.
• Urine discoloration – Entacapone may cause reddish-brown urine, which is harmless.

Common and serious adverse reactions include:

• Dyskinesia (involuntary movements)
• Nausea, vomiting, and diarrhea
• Hallucinations, confusion, or psychotic symptoms
• Low blood pressure and dizziness
• Liver enzyme elevation (possible liver damage)

Entacapone has been associated with mild liver enzyme elevations, but serious liver toxicity is rare. Regular liver function tests (LFTs) may be recommended in patients with pre-existing liver disease or those taking multiple medications that affect liver function.