Clonidine toxicity: Difference between revisions
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**Naphazoline (Naphcon) | **Naphazoline (Naphcon) | ||
**Apraclonidine | **Apraclonidine | ||
*α-2 and opioid receptor agonist | *α-2, imidazoline, and opioid receptor agonist | ||
**α2-agonism leads to activation of inhibitory neurons in the nucleus tractus solitarius causing decreased norepinephrine release, precipitating decreased sympathetic outflow | |||
**Agonism of imidazoline receptors in the brain can cause unconsciousness, hypotension, and bradycardia | |||
*Clonidine is used therapeutically for hypertension, opioid abuse, PTSD, and tobacco withdrawal; criminally, it has been used for drug-facilitated sexual assault | |||
==Clinical Features== | ==Clinical Features== | ||
*Cardiac | *Note that initial presentation may stem from non-specific peripheral alpha1 agonism, and produce hypertension and reflex tachycardia - will transition to bradycardia and hypotension when central effects take over | ||
*Cardiac (alpha2) | |||
**Bradycardia | **Bradycardia | ||
**Hypotension | **Hypotension | ||
*Neuro | *Neuro | ||
**CNS depression (most common) | |||
**Lethargy (may progress to apnea) | **Lethargy (may progress to apnea) | ||
**Miotic pupils | **Miotic pupils | ||
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**Cheynes-Stokes respiration | **Cheynes-Stokes respiration | ||
**Periodic apnea | **Periodic apnea | ||
*Hypothermia | |||
*Can mimic opioid overdose | |||
**obtundation, miosis, respiratory depression, and hypothermia | |||
*Can mimic digoxin, Beta-blocker, or CCB toxicity with hypotension and bradycardia | |||
*Withdrawal from clonidine presents with tachycardia, hypertension, tremors, and agitation | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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==Evaluation== | ==Evaluation== | ||
*Diagnosis is largely based on history and clinical picture; there is no readily available serum test | |||
*Serial ECGs | |||
*Continuous cardiac monitoring | |||
*Clonidine itself does not cause electrolyte derangements | |||
==Management== | ==Management== | ||
*Respiratory/neuro depression | *Respiratory/neuro depression | ||
**[[Naloxone]] | **[[Naloxone]] | ||
***High dose may be required (up to 10mg) | ***High dose may be required (up to 10mg)<ref>Naloxone reversal of clonidine toxicity: dose, dose, dose. Donna L Seger, et al. Clin Toxicol (Phila). 2018.</ref> | ||
***Not always effective | ***Not always effective | ||
***May require infusion, typically 2/3 effective treatment dose per hour | |||
*[[Bradycardia]] | *[[Bradycardia]] | ||
**[[Atropine]] | **[[Atropine]] | ||
*[[Hypotension]] | *[[Hypotension]] | ||
**[[IVF]] | **[[IVF]] | ||
**Vasopressors if not responsive to fluids | |||
==Disposition== | ==Disposition== | ||
Latest revision as of 13:33, 20 September 2021
Background
- Class: Imidazolines
- Clonidine
- Guanfacine
- Oxymetazoline(Afrin)
- Tetrahydrolozine (Visine)
- Naphazoline (Naphcon)
- Apraclonidine
- α-2, imidazoline, and opioid receptor agonist
- α2-agonism leads to activation of inhibitory neurons in the nucleus tractus solitarius causing decreased norepinephrine release, precipitating decreased sympathetic outflow
- Agonism of imidazoline receptors in the brain can cause unconsciousness, hypotension, and bradycardia
- Clonidine is used therapeutically for hypertension, opioid abuse, PTSD, and tobacco withdrawal; criminally, it has been used for drug-facilitated sexual assault
Clinical Features
- Note that initial presentation may stem from non-specific peripheral alpha1 agonism, and produce hypertension and reflex tachycardia - will transition to bradycardia and hypotension when central effects take over
- Cardiac (alpha2)
- Bradycardia
- Hypotension
- Neuro
- CNS depression (most common)
- Lethargy (may progress to apnea)
- Miotic pupils
- Respiratory depression
- Respiratory
- Hypoventilation
- Hypoxia
- Cheynes-Stokes respiration
- Periodic apnea
- Hypothermia
- Can mimic opioid overdose
- obtundation, miosis, respiratory depression, and hypothermia
- Can mimic digoxin, Beta-blocker, or CCB toxicity with hypotension and bradycardia
- Withdrawal from clonidine presents with tachycardia, hypertension, tremors, and agitation
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 | Variable | 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
- Diagnosis is largely based on history and clinical picture; there is no readily available serum test
- Serial ECGs
- Continuous cardiac monitoring
- Clonidine itself does not cause electrolyte derangements
Management
- Respiratory/neuro depression
- Bradycardia
- Hypotension
- IVF
- Vasopressors if not responsive to fluids
Disposition
References
- ↑ Naloxone reversal of clonidine toxicity: dose, dose, dose. Donna L Seger, et al. Clin Toxicol (Phila). 2018.