Acetaminophen Medication Guide PDF

**Acetaminophen** **Classification** Analgesic Antipyretic **Brand Names** Abenol®, Actimol®, Atasol®, Tylenol® **Indications** EMR: mild to moderate pain ACP: mild to moderate pain and pyrexia **Contraindications** - Hypersensitivity to acetaminophen or any component of the formulat...

**Acetaminophen** **Classification** Analgesic Antipyretic **Brand Names** Abenol®, Actimol®, Atasol®, Tylenol® **Indications** EMR: mild to moderate pain ACP: mild to moderate pain and pyrexia **Contraindications** - Hypersensitivity to acetaminophen or any component of the formulation - Severe alcoholic hepatitis or liver dysfunction with active alcohol consumption - Acute liver injury - Acetaminophen-induced liver disease **Adult dosages** EMR: [**[analgesia]**](https://handbook.bcehs.ca/clinical-practice-guidelines/e-medical-emergencies/e08-pain-management/) ACP ([**[analgesia]**](https://handbook.bcehs.ca/clinical-practice-guidelines/e-medical-emergencies/e08-pain-management/) and antipyresis):  - 500-1,000 mg PO (specifically, 15 mg/kg to a maximum of 1,000 mg) - May repeat once after 4 hours - 24-hour maximum: 3 g (3,000 mg)  - In patients with suspected or known liver dysfunction (e.g., advanced chronic liver disease or cirrhosis), the 24-hour maximum should be lowered to 1-2 g (1,000 mg - 2,000 mg)  - May be used concurrently with ibuprofen for analgesia - ***IV dosing regimen will be established once operationalized \-- pending regulatory review*** ACP only: follow analgesia dosing for antipyresis **Pediatric Considerations And Dosing** EMR: [**[analgesia]**](https://handbook.bcehs.ca/clinical-practice-guidelines/e-medical-emergencies/e08-pain-management/) and  ACP ([**[analgesia]**](https://handbook.bcehs.ca/clinical-practice-guidelines/e-medical-emergencies/e08-pain-management/) and antipyresis): - [***[Follow weight-based dosing]***](https://handbook.bcehs.ca/clinical-practice-guidelines/m-pediatric-and-neonatal-emergencies/page-for-age-pediatric-dosages/) - \< 30 kg: 15 mg/kg PO (use liquid preparation) - 30-50 kg: 500 mg PO (may use liquid preparation or tablets, depending on patient ability) - \> 50 kg: 500-1,000 mg PO - May repeat once after 4 hours - 24-hour maximum: 75 mg/kg or 1 g (1,000 mg)  - Do not exceed 5 doses in 24-hours in patients \< 12 years of age - ***IV dosing regimen will be established once operationalized \-- pending regulatory review*** ACP only: follow analgesia dosing for antipyresis **Mechanism Of Action** Acetaminophen inhibits prostaglandin synthetase in the central nervous system, reducing pain and pyrexia.  **Pharmacokinetics** Oral: - Onset: 30 minutes - Peak: 1-3 hours - Duration: 4 hours Intravenous: - Onset: 15 minutes (matching rate of administration) - Peak: 1 hour - Duration: 4-6 hours (analgesia) and \> 6 hours (antipyresis) **Adverse Effects** - Adverse reactions are uncommon with short-term use of acetaminophen - Rash and hives are rarely reported, but can occur - Constipation can develop with long-term use **Overdose** Toxicity may occur after a single dose of more than 7.5 g (adults) or 150 mg/kg (pediatrics).  **Warning And Precautions** Acetaminophen is the leading cause of serious liver injury in Canada.  Patients with pre-existing liver disease (regardless of underlying cause), chronic users of acetaminophen, and pediatrics are at most risk.  Acetaminophen is a component of many over-the-counter medications and patients may inadvertently be consuming much higher doses than expected.  Paramedics must ensure that a complete medication history is obtained prior to the administration of acetaminophen, including over-the-counter preparations. **Drug Interactions** Alcohol may potentiate acetaminophen's hepatoxic effects.