Child Still Sick After Antibiotics? What to Do If They’re Not Getting Better
Quick answer: If your child has started antibiotics but is not improving, is getting worse, or develops new concerning symptoms, the next step is reassessment rather than trying to work out at home whether the antibiotic is “working.” The right timing depends on the illness, the child and the treatment plan.
It can be unsettling when you have already taken your child to a doctor, started the prescribed treatment and expected things to turn around — but your child is still sick.
Parents commonly search “how long do antibiotics take to work?”, “antibiotics not working after 3 days” or “fever after antibiotics”. The practical question is usually more specific: Is my child improving as expected, and what should I do if they are not?
This guide is designed to help Australian parents navigate that next step. It does not diagnose the cause of ongoing symptoms or tell you to change, stop or start a medicine.
How long do antibiotics take to work?
There is no single timeline that applies to every infection or every child. Some childhood bacterial infections may begin to show clinical improvement within roughly 48–72 hours of appropriate treatment, but the expected course varies by diagnosis. For example, Royal Children’s Hospital guidance notes that children with uncomplicated bacterial pneumonia usually improve within about 48 hours, while other conditions have different review points.
That is why the most useful question is not simply “Has it been two or three days?” but:
Is my child clearly improving, staying about the same, or getting worse?
Are the symptoms that led us to seek care improving?
Has anything new developed since the original assessment?
Did the clinician give us a specific timeframe or follow-up plan?
Child still sick after antibiotics? Use this next-step pathway
1. Your child is getting worse
A child who is deteriorating should not be made to wait for an arbitrary antibiotic timeline. Seek prompt medical reassessment. If your child appears seriously unwell or has emergency symptoms — such as significant difficulty breathing, blue or very pale lips/skin, being difficult to wake, a seizure, or other signs that make you think this may be an emergency — call 000 or attend an emergency department.
For less immediate concerns, the appropriate service might be the clinician who originally assessed your child, your GP, an after-hours service, a Medicare Urgent Care Clinic, a virtual emergency service where available, or an emergency department depending on how unwell your child is.
2. Your child is not worse — but they are not improving
This is where many parents become unsure whether to keep waiting. If your child is not improving within the timeframe you were given, or you are concerned that the expected improvement is not happening, contact the healthcare professional or service that assessed them for advice or reassessment.
The 48–72 hour mark appears in a number of paediatric clinical pathways, but it is not a universal rule for every infection. For example, Royal Children’s Hospital guidance recommends further assessment when pneumonia fails to clinically improve after 48–72 hours of appropriate antibiotic therapy, while its cellulitis guideline recommends review when there is no improvement or deterioration after 24–48 hours.
3. Some things are better, but other symptoms remain
Recovery is not always all-or-nothing. A child may improve in one way while still having a cough, tiredness, reduced appetite or another symptom. Rather than deciding from one symptom alone whether treatment has failed, look at the overall direction of the illness and the follow-up advice you were given.
If you are unsure whether a remaining symptom is expected for the illness your child was diagnosed with, ask the treating clinician rather than changing the antibiotic yourself.
4. Your child finished the antibiotics but is still sick
Finishing the course does not automatically mean every symptom should have disappeared. Some symptoms can persist during recovery. However, if your child has not improved as expected, symptoms are returning, or new symptoms have appeared, arrange follow-up with a healthcare professional.
Bring the original diagnosis and treatment details with you if you can. The next clinician may need to reassess whether the original diagnosis still fits, whether another illness is present, whether tests or results need review, or whether the management plan needs to change.
5. Fever is continuing or has come back after antibiotics
Persistent or returning fever is one of the most common reasons parents question whether antibiotics are working. Fever alone cannot tell you why a child is still unwell, and antibiotics do not treat viral infections.
If fever is continuing beyond the timeframe your clinician expected, returns after improvement, or your child is becoming more unwell, seek reassessment. Young babies with fever need particular caution: a baby under 3 months with fever should be medically assessed promptly in an Emergency Department.
Antibiotics not working after 3 days: what happens next?
Three days is a common search point because parents expect to see some change by then. But “three days” should not be treated as a home diagnostic test for whether an antibiotic has failed.
At reassessment, a clinician may review the child’s current symptoms and observations, reconsider the original diagnosis, check whether any test or culture results are now available, confirm how the medicine has been taken, and decide whether further examination, investigation or a change in management is needed.
The useful role for a parent is not to decide which of those explanations applies. It is to recognise when the child is not following the expected recovery path and make sure that information gets back to an appropriate clinician.
Why might a child still be sick?
There are many possible reasons, and they cannot be reliably separated by a parent from symptoms alone. Antibiotics only treat bacterial infections, so an illness caused by a virus will not improve because of an antibiotic. In other situations, the diagnosis may need to be reconsidered, a bacterial infection may need further assessment, or the child may simply still be recovering.
Avoid assuming that persistent symptoms automatically mean antibiotic resistance or that your child needs a stronger antibiotic. That decision requires clinical assessment.
What to take to the reassessment
A short, organised timeline can make a repeat appointment much more useful. Before you go, write down:
the name of the antibiotic and when it was started
the prescribed dose and schedule
whether any doses were missed, spat out or vomited
the symptom or diagnosis the antibiotic was prescribed for
what has improved since treatment started
what has stayed the same
what has become worse or newly appeared
fever/temperature pattern if relevant
how your child is drinking, eating, urinating and behaving compared with usual
any tests that were done and whether results are still pending
the advice you were originally given about when to return.
Questions you can ask at the follow-up
Is this recovery pattern what you would expect for the diagnosis?
Does my child need to be examined again today?
Are there any test or culture results that need reviewing?
What changes should prompt another review?
Who should I contact if my child still is not improving?
What is the follow-up plan from here?
Where should I take my child for reassessment?
The right place depends on how unwell your child is and what services are available where you live. If the concern is non-emergency and your child is stable, the original prescriber or your usual GP may be the most useful starting point because they know the original assessment and treatment plan.
If you cannot access your usual clinician, an after-hours GP, Medicare Urgent Care Clinic or virtual emergency service may be an option. If your child is deteriorating, has significant breathing difficulty, is difficult to wake, has a seizure, looks seriously unwell, or you believe the situation is an emergency, seek emergency care or call 000.
Do not change the antibiotic on your own
Give medicines exactly as prescribed unless the treating healthcare professional tells you otherwise. Generally advise usually involves completing the prescribed antibiotic course, even if a child feels better before it is finished. If there is a problem taking the medicine, a suspected reaction, repeated vomiting of doses, or you think the treatment is not working, contact the prescriber for individual advice.
The key question: is your child following the expected recovery path?
When your child is still sick after antibiotics, you do not need to diagnose why before asking for help. Compare what is happening now with the plan you were given. If your child is getting worse, not improving as expected, develops new concerning symptoms, or you simply cannot reconcile what you are seeing with the expected recovery, seek reassessment.
A repeat review is not a failure of the first consultation. Children’s illnesses evolve, new signs can appear and information such as test results may become available later. Your job as the parent is to notice the trajectory and communicate what has changed.
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Important
This article provides general navigation information for Australian parents and does not replace assessment by a qualified healthcare professional. It does not diagnose infection, determine whether an antibiotic is appropriate, or provide individual medication advice. Follow the instructions given by your child’s treating clinician and pharmacist. In an emergency, call 000.
