What are the expected vital signs in a patient who has overdosed on ropinirole (Requip)?

Expected Vital Signs in Ropinirole (Requip) Overdose

Patients with ropinirole overdose typically present with hypotension, tachycardia, nausea, dizziness, and altered mental status due to its dopaminergic activity.

Cardiovascular Manifestations

• Blood pressure: Significant orthostatic hypotension is the most prominent vital sign abnormality 1, 2
  • Supine BP may be normal or mildly decreased
  • Standing BP often shows marked drops (>20-30 mmHg systolic)
• Heart rate: Typically increased (tachycardia) as a compensatory response to hypotension 1
  • May see paradoxical bradycardia in severe cases due to vasovagal effects 1
• ECG changes: Possible palpitations and rhythm disturbances in severe cases 1

Neurological Manifestations

• Mental status: Varying degrees of altered consciousness from somnolence to confusional states 1
• Respiratory rate: Usually normal unless severely intoxicated, when respiratory depression may occur
• Temperature: Generally normal, though hyperhidrosis (excessive sweating) may be present 1

Severity Assessment

The severity of vital sign abnormalities correlates with the ingested dose:

1. Mild to moderate overdose (typically <24 mg/day):

   • Orthostatic hypotension (BP drop >10-20 mmHg upon standing)
   • Mild tachycardia (HR 90-110 bpm)
   • Normal respiratory rate and temperature

2. Severe overdose (>24 mg/day or >60 mg/day in extreme cases):

   • Significant hypotension (systolic BP <90 mmHg)
   • Marked tachycardia (HR >120 bpm) or paradoxical bradycardia
   • Possible respiratory depression in extreme cases
   • Normal or slightly elevated temperature

Monitoring Considerations

Blood pressure monitoring should include both supine and standing measurements to detect orthostatic changes, which are particularly common with ropinirole toxicity 2, 3. In fatal cases, peripheral blood concentrations of ropinirole have been reported at 64-100 ng/mL, far exceeding therapeutic levels of 0.4-6 ng/mL 4, 5.

Associated Clinical Findings

Beyond vital signs, patients with ropinirole overdose commonly exhibit:

• Nausea and vomiting
• Visual hallucinations
• Chorea or dyskinesia
• Dizziness
• Syncope or near-syncope
• Agitation or confusion
• Increased coughing
• Fatigue and asthenia 1

Management Implications

When these vital sign abnormalities are detected:

• Maintain vital sign monitoring with particular attention to orthostatic changes
• Provide supportive care with IV fluids for hypotension
• Consider high-dose insulin with glucose for refractory shock if beta-blocker properties contribute to hemodynamic instability 6
• Discontinue the medication and observe for at least 24 hours as effects may be prolonged

Pitfalls to Avoid

• Failing to check orthostatic vital signs, which may miss significant postural hypotension
• Attributing symptoms solely to other conditions when a patient is on ropinirole
• Overlooking the potential for a prescribing cascade where additional medications are added to treat side effects of ropinirole 2
• Underestimating the severity of overdose based on initial vital signs, as deterioration may occur

Careful monitoring of vital signs with attention to orthostatic changes is essential in managing patients with suspected ropinirole overdose, as these changes often precede more serious clinical manifestations.