Q: Is the fever reducer not working? My child has a history of febrile seizures and the fever isn't dropping.
Medically reviewed by Sang Hyun Ahn, MD
Content edited by Myeongchan Kim, MD
This post is a dramatization of a question and answer session experienced by our actual medical reviewers. Please note that this content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
Question:
My child weighs 12.4 kg and has a history of febrile seizures, so I give them a fever reducer even for a mild fever. We saw a doctor on Thursday for a cough with phlegm, and a fever started on Friday morning. As soon as their temperature reached 37.8°C, I gave 5 mL of acetaminophen and continued giving it every 6 hours. Since early this morning, the temperature has been 38.2°C, so I have been giving the medication every 4 hours.
However, even an hour after taking the medicine, there is little to no change in their temperature. Does this mean the fever reducer isn't working? Or does it mean it is working if the temperature drops to normal or around 37.5°C two hours after taking it?
Answer:
It is completely understandable that you are feeling extra anxious given your child's history of febrile seizures.
Here is a breakdown of what is likely happening and how to assess if the medication is working:
How Fever Reducers Work
Timing: Fever reducers typically start working 30 minutes to 1 hour after taking them, but they reach their maximum effect about 1 to 2 hours after the dose.
The Goal: The goal of fever medication is not necessarily to bring the body back to a "normal" temperature. If the medication lowers the temperature by 0.5 to 1°C and makes your child feel more comfortable, it is working.
Stubborn Fevers: During the early stages of a viral infection, the body's drive to increase its temperature is very strong. It is quite common for a child's temperature to hover around 37.5°C to 38°C even after taking a fever reducer.
What You Should Do Now
Dosage Check: For a child weighing 12.4 kg, the appropriate acetaminophen dose is generally 124–186 mg per dose. Assuming you are using a standard 160 mg/5 mL concentration, a 4 to 6 mL dose is correct. Therefore, the 5 mL you are giving is right on target.
Observe: Wait up to 2 hours after administering the medication to check the temperature again and evaluate your child's overall condition.
Comfort Measures: Encourage your child to drink lukewarm water frequently to stay hydrated. Dress them in light, breathable clothing, and keep the room temperature comfortable (around 22–24°C).
Dosing Intervals: Make sure to maintain at least a 4-hour interval between acetaminophen doses, and do not exceed 5 doses in a 24-hour period.
When to Seek Immediate Medical Care (ER or Urgent Care)
Please take your child to an emergency room or urgent care center immediately if any of the following occur:
A febrile seizure occurs again (especially if it lasts longer than 5 minutes, if they do not regain consciousness, or if it repeats).
They show signs of breathing difficulty (e.g., skin pulling in under the ribs, nasal flaring, or wheezing).
They are extremely lethargic, cannot make eye contact, or have not urinated in over 8 hours.
The fever lasts for more than 3 days or progressively gets worse.
It is very common for a fever not to drop completely even after medication is given. Please continue to monitor both their temperature and overall condition 2 hours after each dose. If you remain concerned, if the fever persists, or if you are unsure about their symptoms, please follow up with your pediatrician or visit a local urgent care clinic for an in-person evaluation.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
