A fatal intoxication case involving ropinirole

Ropinirole, a specific non-ergoline dopamine D2-receptor agonist, belongs to the drugs applied in treatment of Parkinson's disease (PD) and restless legs syndrome (RLS) and acts as a D2, D3, and D4 dopamine receptor agonist with highest affinity for D3. Therapeutic ropinirole plasma levels in adults are defined between 0.4 and 6 ng/mL. This case report documents a fatal intoxication involving ropinirole. Information about lethal ropinirole concentrations is hitherto lacking in the literature and the assessed ropinirole levels of this case may present a step towards defining potentially lethal concentrations. A 37-year-old man without medical history was found dead in a converted van used as place of residence and an autopsy was performed. The pathological findings did not reveal an apparent cause of death but the toxicological analysis revealed the presence of ropinirole, paracetamol, and alcohol in the peripheral blood sample. Quantitative analysis revealed that ropinirole was present at a peripheral blood concentration of 64 ng/mL. The ropinirole concentrations determined in vitreous humor, urine and bile were respectively, 11 ng/mL, 2670 ng/mL and 826 ng/mL. Paracetamol was detected at a blood level of <2 μg/mL. Based on the autopsy findings and toxicological results, the cause of death was primarily attributed to intoxication with ropinirole in combination with alcohol.