Children and medicines: dosing, forms and common mistakes

With children, what counts is not age but body weight: the right amount of fever syrup for a slight three-year-old is different from that for a sturdy one. This guide shows you how to dose active ingredients such as Paracetamol and Ibuprofen safely, which dosage form suits which situation and which parental mistakes happen most often — but the package leaflet and your paediatric practice always remain the authority.

1. Why children are dosed differently

Children are not small adults. Their bodies distribute, process and excrete active ingredients differently — a toddler's liver and kidneys do not yet work like an adult's. That is why you cannot simply take the adult dose "a bit smaller". Instead, the amount is almost always based on body weight and given in milligrams per kilogram (mg/kg).

Age is only a rough guide, because children of the same age can weigh very different amounts. Two four-year-olds can differ by several kilos — and therefore in the right dose. Packages often give age ranges because manufacturers need a simple rule of thumb; the safe basis, however, is your child's current weight. When in doubt, weigh them rather than guessing.

Important to understand: the figures in this guide are meant for orientation, not as a prescription. The binding dose is stated in the package leaflet of the specific product — because syrups come in different concentrations — and is confirmed by your paediatric practice or pharmacy if you are unsure.

2. Dosing by body weight: a worked example

The two most common fever and pain medicines for children are Paracetamol and Ibuprofen. Both are dosed by weight. Here is how the principle works for an example child weighing 15 kg (about 3–4 years old):

Calculation for Paracetamol: 15 kg × 12 mg/kg ≈ 180 mg per single dose. If the syrup contains, for example, 200 mg per 5 ml, that corresponds to just under 4.5 ml. Sounds simple — but this is exactly where most mistakes happen, because syrups are sold in different strengths. A "2 per cent" and a "4 per cent" fever syrup need completely different millilitre amounts for the same child. So never rely on the ml figure from memory; look it up for exactly the bottle in front of you.

3. Dosing and giving fever syrup correctly

Fever itself is not an illness but a useful defence reaction. So not every fever needs to be brought down straight away — what matters is how your child is doing. A child who drinks, plays and is responsive despite a raised temperature often needs no fever medicine at all. Fever syrup makes sense above all when your child is visibly suffering, drinks poorly or is in pain.

When you dose, keep these points in mind:

• Check the concentration: Does the bottle state how many mg of active ingredient are contained in 5 ml (or per ml)? The millilitre amount depends on this.
• Measure with the dosing syringe: The supplied syringe or measuring cup is matched to the product — a kitchen spoon is not.
• Keep the minimum interval: Better to check the clock than to top up "by feel". Note the time of the last dose.
• Not long-term without medical advice: If fever persists for several days, it needs to be checked by a doctor.

Whether you may give Paracetamol and Ibuprofen alternately is a common question. In principle this only makes sense on medical advice — alternating increases the risk of dosing errors and is not routinely recommended. Better to stick to one active ingredient and the intended intervals.

4. Syrup, suppository or melt tablet?

The same active ingredient often comes in several forms. Which one fits depends on the age, the situation and on whether your child is currently vomiting or can swallow something.

A common misconception: suppositories do not work more weakly, but their absorption through the bowel is somewhat less predictable than with syrup. Also, do not cut suppositories lengthwise to dose "half" — the active ingredient is not evenly distributed. If you need a smaller amount, take the appropriate suppository strength for infants or toddlers.

5. The most common parental mistakes

Most problems arise not from the medicine itself but from how it is used. These mistakes keep coming up — and are easy to avoid:

• Downsizing the adult dose: A "half adult tablet" is not a child-appropriate dose. Children need the weight-based amount, often from a children's dosage form.
• Kitchen spoon instead of a measuring aid: A teaspoon holds 3–7 ml depending on the model — that can almost double the dose. Always use the supplied syringe or measuring cup.
• Giving too often: Out of worry, another dose is given before the minimum interval is over. This makes the daily amount add up dangerously. Write down the time of every dose.
• Two products with the same active ingredient: A fever syrup and a cold combination product sometimes both contain Paracetamol — together they risk an overdose. Always check the active ingredients, not just the product names.
• Dosing by age instead of weight: Especially with slight or sturdy children, going purely by the age range leads to over- or under-dosing.

6. Antibiotics and gastrointestinal medicines in children

Prescription-only medicines are also dosed by weight in children. A frequently prescribed antibiotic is Amoxicillin, usually as a syrup. Two things are crucial here: first, the duration of treatment set by the paediatrician must be observed, even if the child is already feeling better. Second, antibiotic syrups are often only mixed with water at the pharmacy and then have a limited shelf life — note the expiry date after mixing and shake before each dose.

With a gastrointestinal infection, the focus in children is not on stopping the diarrhoea but on replacing fluids and salts — for example with a special electrolyte solution from the pharmacy. Anti-nausea medicines such as Metoclopramide are only suitable in children to a limited extent and exclusively on medical instruction — do not give them on your own initiative. If your child keeps nothing down or shows signs of dehydration, they need to be examined by a doctor.

7. When you need the paediatrician or emergency services

Treating mild infections yourself is fine — but there are clear limits. Get medical help if:

• an infant under 3 months has a fever — always have this checked immediately.
• your child stops drinking, becomes noticeably less wet (dry nappy) or seems sunken/apathetic.
• high fever comes with refusal to drink, listlessness or dehydration.
• fever lasts longer than one or two days or the child seems increasingly unwell.
• a skin rash, breathing difficulty, a stiff neck or seizures occur — then call the emergency services (112) immediately.

When in doubt: better to call once too often. Your child's general condition says more than the mere number on the thermometer.

8. Your checklist before every dose

• Take weight rather than age as the basis and check the dose for exactly this product.
• Read the concentration — how many mg of active ingredient per 5 ml? Then calculate the millilitres.
• Use the supplied dosing aid — dosing syringe or measuring cup, never the kitchen spoon.
• Note the time and keep to the minimum interval and the maximum daily amount.
• Cross-check active ingredients — no medicine twice, no ASA with feverish infections.

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