Download Treatment of an Acetaminophen Overdose

Level 3
Organ System: Digestive System
Disease State: Gastrointestinal / Mental
Curriculum Topic: Pharmacy Practice / Pharmacist-Provided Care / Pharmacotherapy
Treatment of an Acetaminophen Overdose
Mate M. Soric, PharmD
Assistant Professor of Pharmacy Practice, Northeastern Ohio Universities College of Pharmacy
Key Learning Objectives
1. Describe the pathophysiology of acetaminophen overdose,
including normal acetaminophen metabolism, toxic metabolite production, and the mechanism of cellular damage.
2. Identify patient risk factors for the development of liver injury or failure following an acute acetaminophen overdose.
Social History

Smoker: 1.5 pack per day x 11 years

Denies drinking alcohol

Denies illicit drug use
Family History

Mother and sister are poly-substance abusers
3. Explain the most common signs and symptoms of acetaminophen overdose.
V i tals: A dmission
4. Use patient information to design a pharmaceutical care
plan for the treatment of acetaminophen overdose, including rationale for treatment choices, administration instructions, and appropriate monitoring parameters.
Case Presentation
History of Present Illness
RG is a 27-year-old female (5'4" and 73 kg) presenting to the Emergency Department via EMS squad at 22:30. Earlier that evening, RG
and her mother had a heated argument. Shortly thereafter at 20:45,
her mother called 911 after discovering RG in her bedroom with two
open 100-count bottles of extra-strength acetaminophen (500 mg) on
the nightstand. The EMS squad counted 63 tablets remaining in the
first bottle and found the second bottle empty. No other medication vials were present in the bedroom. RG explained that she had taken only
four acetaminophen tablets for a severe headache after the argument
with her mother. Currently, RG is complaining of nausea.
Temp.
HR
BP
RR
(°C)
(beats/min)
(mmHg)
(breaths/min)
36°
101
144/89
15
Physical Examination

General: patient in some distress; looks older than stated age

Skin: moist mucus membranes

Abdomen: bowel sounds present

Neurological: alert & oriented (A&O) x 3
Allergies/Adverse Drug Reactions

Hydromorphone (nausea)

Lisinopril (nausea)

Nitroglycerin (muscle twitching)
L abs : obtained at 22: 35
Allergies
Na 139 mmol/L
Glu 4.3 µmol/L
INR 1.0

None
K 4.3 mmol/L
Ethanol neg
AST 41 U/L
Past Medical History
Cl 102 mmol/L
Pregnancy neg
ALT 36 U/L

Major Depressive Disorder x 9 years

History of suicidal gestures

Irritable Bowel Syndrome (IBS), constipation predominant x 1 year
CO2 25 mmol/L
APAP 132 µmol/L
Alk Phos 77 U/L
BUN 7.85 mmol/L
THC pos
T Bili 13.7 µmol/L
SCr 53 µmol/L
Albumin 38g/L
Medications

Sertraline 200 mg daily x 3 months

Lubiprostone 8 µg twice daily x 6 months
remington pharmed cases
•
march 2011 / case presentation: Soric, page 1
w w w . p h a r m p r es s .com/casestudies
Assessment Questions
1. Describe the metabolism of acetaminophen, both at therapeutic and toxic doses, and the effects of its metabolites on
hepatocytes.
2. What are the most common signs and symptoms of acetaminophen overdose?
3. List three risk factors for the development of liver injury or
failure following a toxic ingestion of acetaminophen.
4. Approximately what single dose of acetaminophen is likely
to cause toxicity in patients with no additional risk factors?
5. Design a pharmaceutical care plan for the treatment of
RG’s acute condition.
(answers on page 10)
Further Reading
1. Dart RC, et al. (1997). Acetaminophen (paracetamol). In Dart
RC, ed. Medical Toxicology. Philadelphia: Lippincott Williams and
Wilkins, 723–738.
2. Dart RC, et al. (1997). N-Acetylcysteine. In Dart RC, ed. Medical Toxicology. Philadelphia: Lippincott Williams and Wilkins,
223–227.
3. Dart RC, et al. (2006). Acetaminophen poisoning: an evidencebased consensus guideline for out-of-hospital management.
Clin Toxicol 44: 1–18.
4. Rowden AK, et al. (2005). Updates on acetaminophen toxicity.
Med Clin N Am 89: 1145–1159.
5. Wolf SJ, et al. (2007). Clinical policy: critical issues in the management of patients presenting to the emergency department with
acetaminophen overdose. Ann Emerg Med 50: 292–313.
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remington pharmed cases
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march 2011 / case presentation: Soric, page 2
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