Caffeine toxicity


  • Overdose is more common in young children
  • Caffeine overdoses in adults are rare and typically require ingestion in excess of 5 g[1]
  • Toxic levels are considered to be 150-200mg/kg[2]

Common Dosages by Type

Type Amount Caffeine^
Coffee, brewed 1 cup 100mg
Coffee, instant 1 cup 75mg
Tea 1 cup 50mg
Red Bull 1 can 80mg
Rockstar 1 can 160mg
Excedrin Migraine 2 tabs 130mg

^Average caffeine content can vary[3][4]

Clinical Features

  • Sympathomimetic[5]
    • Delusions
    • Paranoia
    • Tachycardia
    • Hypertension
    • Hyperpyrexia,
    • Diaphoresis
    • Piloerection
    • Mydriasis
    • Hyper-reflexia
    • Seizures
    • Hypotension
    • Dysrhythmias
  • Additional symptoms[6]
    • Neuro: Agitation, anxiety, excitement, or restlessness; confusion or delirium; seizures
    • CV: Tachycardia and palpitations
    • HEENT: Tinnitus, “zig-zag” flashes of light
    • GI: Abdominal pain, nausea/vomiting
    • Renal: Dehydration,
    • MSK: Muscle trembling or twitching
    • Newborns: Whole-body tremors, painful, swollen abdomen with nausea

Differential Diagnosis



  • With clear history, no further work up is indicated
  • With altered mental status or ambiguous presentation consider:
    • Urinalysis, CBC, BMP, LFTs
    • CT head
    • tox workup
    • infectious work up


Treatment varies by severity of presentation[7]

  • Airway
    • Intubation is needed for altered mental status or seizures
  • Breathing
    • Supplemental O2
    • Ventilation
  • Circulation
    • IVF
    • Vasopressors for refractory hypotension (Norepi vs phenylephrine)
    • BB or CCB for tachycardia (Esmolol or Propranolol)
    • If Vtach, initiate code protocol
  • Benzodiazepines for agitation
  • Treat hypokalemia if K<3 and rhabdo (potassium depletion is due to intracellular shift rather than body depletion)
  • Antiemetics as needed
  • HD can be used in severe cases
  • Consult Poison Control


  • Admit all clinically unstable patients, suicide attempts, or those with ambiguous diagnoses

See Also

External Links


  1. Kerrigan S, et al. Fatal caffeine overdose: two case reports. Forensic science international. 2005; 153(1):67-69.
  2. Peters JM. Factors Affecting Caffeine Toxicity: A Review of the Literature. The Journal of Clinical Pharmacology and the Journal of New Drugs. 1967; 7(7):131–141.
  3. Food Standards Agency (2001) Statement on the Reproductive Effects of Caffeine. London: Food Standards Agency.
  4. Juliano LM and Griffiths RR. Caffeine. In Lowinson, J.H., Ruiz, P., Millman, R.B., Langrod, J.G. (Eds.). Substance Abuse: A Comprehensive Textbook, Fourth Edition. 2005. PP. 403-421. Baltimore: Lippincott, Williams, & Wilkins.
  5. Marx JA, Hockberger RS, Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Philadelphia, PA: Mosby/Elsevier; 2010.
  6. Shannon MW. Theophylline and caffeine. In: Shannon MW, Borron SW, Burns MJ, eds. Haddad and Winchester's Clinical Management of Poisoning and Drug Overdose. 4th ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 65.
  7. Yew D, et al. Caffeine Toxicity Treatment & Management. Medscape. Updated: Mar 31, 2014.