From the FDA Drug Label
Adults and Adolescents Weighing 50 kg and Over: 1000 mg every 6 hours or 650 mg every 4 hours to a maximum of 4000 mg per day. Adults and Adolescents Weighing Under 50 kg: 15 mg/kg every 6 hours or 12. 5 mg/kg every 4 hours to a maximum of 75 mg/kg per day. Children: Children 2 to 12 years of age: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours to a maximum of 75 mg/kg per day.
The recommended IV dose of paracetamol for headache is:
- For adults and adolescents weighing 50 kg and over: 1000 mg every 6 hours or 650 mg every 4 hours
- For adults and adolescents weighing under 50 kg: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours
- For children 2 to 12 years of age: 15 mg/kg every 6 hours or 12.5 mg/kg every 4 hours 1
From the Research
The recommended intravenous (IV) dose of paracetamol for headache in adults is 1000 mg (1 gram) administered over 15 minutes, with a maximum of 4 grams per 24 hours and minimum interval of 4 hours between doses. For patients weighing less than 50 kg, the dose should be reduced to 15 mg/kg. IV paracetamol works by inhibiting cyclooxygenase enzymes and modulating pain pathways in the central nervous system, providing effective analgesia with a rapid onset of action (within 15 minutes) 2. This route is particularly useful when oral administration is not possible or when rapid pain relief is needed. The infusion should be administered slowly to minimize the risk of hypotension. Patients should be monitored for potential adverse effects including liver toxicity, especially in those with pre-existing liver disease, malnutrition, or chronic alcohol use 3, 4. IV paracetamol should be used cautiously in patients with severe renal impairment, and dose adjustments may be necessary in elderly patients or those with hepatic insufficiency.
Some key points to consider when administering IV paracetamol include:
- Monitoring liver function, especially in patients with pre-existing liver disease or those taking other hepatotoxic medications 5
- Avoiding overdose, as this can lead to severe liver injury and even death 2
- Using the minimum effective dose to minimize the risk of adverse effects 4
- Considering alternative pain management options in patients with severe renal impairment or hepatic insufficiency 3
It's also important to note that while paracetamol is generally considered safe and effective for headache treatment, its use should be carefully monitored and managed to minimize the risk of adverse effects, particularly liver toxicity 2.