Paediatric paracetamol dose when several formulations are in stock
A 3-year-old boy weighing 14 kg is brought to a PHC with fever of 39.2°C and mild dehydration. The medical officer diagnoses viral fever and prescribes paracetamol 15 mg/kg per dose every 6 hours for 3 days. The pharmacy has three paracetamol products: syrup 125 mg/5 mL, syrup 250 mg/5 mL, 500 mg tablets, and 170 mg suppositories. The mother says the child vomited about 10 minutes after the last dose given at home. The helper must dispense the correct product, write a label in the local language, and counsel the mother. The child refuses to swallow tablets, and the PHC has only 10 mL and 5 mL oral syringes but no measuring spoon.
1. Calculate the prescribed dose and the volume or amount needed for each available formulation, and decide which product should be dispensed.
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Calculations:
- Dose = 14 kg × 15 mg/kg = 210 mg per dose.
- 125 mg/5 mL syrup: 210 ÷ 125 × 5 = 8.4 mL.
- 250 mg/5 mL syrup: 210 ÷ 250 × 5 = 4.2 mL.
- 500 mg tablet: 210 ÷ 500 = 0.42 tablet - not practical or accurate for a 3-year-old.
- 170 mg suppository: about 12 mg/kg, slightly below the prescribed 15 mg/kg but within a reasonable range; it is a reserve option if the child vomits.
Dispense the 250 mg/5 mL syrup, because 4.2 mL is easily measured with the available 5 mL oral syringe and gives a smaller volume for a young child. The 125 mg/5 mL product would require 8.4 mL and is more dilute; either is acceptable if the strength is clearly labelled, but the 5 mL syringe makes the 250 mg/5 mL product safer. Do not dispense the 500 mg tablet for this child.
2. What should be done about the dose the child vomited, and what safety advice should be given about repeat dosing?
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Vomited dose: if a child vomits within about 10–15 minutes of a paracetamol dose, most of the drug has not been absorbed, so one repeat of the full dose is generally acceptable. Do not repeat again if the child vomits the repeat. If vomiting continues, use the 170 mg suppository rectally and arrange medical review; do not give oral and rectal paracetamol at the same time.
Safety counselling:
- Give every 6 hours, maximum 4 doses in 24 hours (maximum 840 mg/day for this child).
- Do not give any other fever medicine containing paracetamol without asking.
- Use the oral syringe, not a household spoon.
- Shake the bottle before each dose.
- Stop and return if the child becomes drowsy, refuses feeds, has repeated vomiting, or the fever lasts more than 3 days.
3. Write the label content and the counselling points the helper should use when handing over the medicine.
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Label (local language):
- Paracetamol syrup 250 mg/5 mL
- Give 4.2 mL by mouth every 6 hours
- Maximum 4 doses in 24 hours
- For fever
- Shake well before use
- Store below 30°C, away from light
- Patient name, date of dispensing, and 'do not use after [date]'
Counselling points: demonstrate 4.2 mL with the syringe and explain that the 5 mL mark is not the dose. Ask the mother to repeat back the dose and timing. Explain the danger of giving extra doses if fever persists. Record the batch number and expiry in the dispensing register. Because the child is dehydrated, encourage ORS and feeding; paracetamol does not treat dehydration. Advise return if danger signs appear.