Clenbuterol toxicity

(Redirected from Clenbuterol)

This page refers to Clenbuterol overdose not dosing of Clenbuterol


  • Clenbuterol is found as an adulterant in both cocain and heroin. There have been many reports of clenbuterol overdoses and outbreaks.[1] It is a long acting B2-agonist used internationally and within the US mainly in veterinary medicine as bronochodilator. In addition to being added into heroin it is also used to increase lean mass of livestock and in racehorses[2]
  • Athletes and body builders also abuse clenbuterol in order to increase muscle mass and decrease body fat.
  • Street Name: Clen
  • Formulation: Tablet or syrup
  • Half Life: 25-39 hrs

Clinical Features

  • Nausea
  • Palpitations
  • Chest pain
  • Dyspnea
  • Tachycardia
  • Mydriasis
  • Tremors
  • Agitation and COnfusion

If mixed with cocaine there will be a sympathomimetic toxidrome

Differential Diagnosis

Altered mental status and fever

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


Lab testing may show:

  • Hyperglycemia
  • Hypokalemia
  • Hypophosphatemia

The effects are due to the β-agonist effects. In patients with associated chest pain, a cardiac workup (ECG, and troponin) should be performed.


Supportive care should include:

Severe Overdoses

  • In an isolated severe overdose without associated cocaine igestions, β-blockade can be given via IV metoprolol, labetolol or esmolol
  • Beta blockade may reverse the associated hypotension from the excessive Beta agonism of the clenbuterol[4]
    • Do not administer β-blocker if there is a chance of associated cocaine use. Diltiazem is an alternative for these situations[4]


  • Most patients require admission due to the long half life of clenbuterol
  • Patients with severe symptoms or those with myocardial ischemia should be admitted for continued monitoring and appropriated cardiac managment[5]
  • Contact poison control

See Also

External Links

CDC MMWR Atypical Reactions Associated With Heroin Use — Five States, January–April 2005


  1. CDC. Atypical reactions associated with heroin use - five states, Jan-April 2015. MMWR. 20025;54(32):793-796
  2. Hoffman RS, Kirrane BM, et al. A descriptive study of an outbreak of clenbuterol-containing heroin. Ann Emerg Med. 2008;52(5):548-553
  3. O'Connor AD, Padilla-Jones A, Gerkin AD, et al. Prevalence of Rhabdomyolysis in Sympathomimetic Toxicity: a Comparison of Stimulants. J Med Toxicol 2014
  4. 4.0 4.1 Barry AR, Graham MM. Case report and review of clenbuterol cardiac toxicity .J Cardiol Cases. 2013;8:131-133
  5. Werder G. et al. Clenbuterol-contaminated heroin: Cardiovascular and metabolic effects. A case series and review. Conn Med. 2006; 70(1):5-11