Clonidine toxicity

2D molecular structure of Clonidine

Background

  • Class: Imidazolines
  • α-2 and opioid receptor agonist

Clinical Features

  • Note that initial presentation may stem from non-specific peripheral alpha1 agonism, and produce hypertension and reflex tachycardia
  • Cardiac (alpha2)
    • Bradycardia
    • Hypotension
  • Neuro
    • Lethargy (may progress to apnea)
    • Miotic pupils
    • Respiratory depression
  • Respiratory
    • Hypoventilation
    • Hypoxia
    • Cheynes-Stokes respiration
    • Periodic apnea

Differential Diagnosis

Toxidrome Chart

Finding Cholinergic Anticholinergic Sympathomimetic Sympatholytic^ Sedative/Hypnotic
Example Organophosphates TCAs Cocaine Clonidine ETOH
Temp Nl Nl / ↑ Nl / ↑ Nl / ↓ Nl / ↓
RR Variable Nl / ↓ Variable Nl / ↓ Nl / ↓
HR Variable ↑ (sig) Nl / ↓ Nl / ↓
BP Nl / ↓ Nl / ↓
LOC Nl / Lethargic Nl, agitated, psychotic, comatose Nl, agitated, psychotic Nl, Lethargic, or Comatose Nl, Lethargic, or Comatose
Pupils Varriable Mydriatic Mydriatic Nl / Miotic
Motor Fasciculations, Flacid Paralysis  Nl Nl / Agitated Nl
Skin Sweating (sig) Hot, dry Sweating Dry
Lungs Bronchospasm / rhinorrhea Nl Nl Nl
Bowel Sounds Hyperactive (SLUDGE) ↓ / Absent Nl / ↓ Nl / ↓
^Consider Sympatholytic when looking at Sedative OD or someone who doesn't respond to Narcan
Withdrawal from substances have the opposite effect

Evaluation

Management

Disposition

References


See Also

Toxicology (Main)