Medicines for children: dosing, liquids and safe use

A child's liver, kidneys and body water change rapidly from the newborn period through to adolescence, which affects how a medicine is absorbed, broken down and cleared. For that reason doses for children are not simply a fraction of the adult dose, and they are set using age, and in some cases weight, rather than a single standard strength.

NHS guidance on children's paracetamol shows the principle in practice. Dosing depends primarily on age, with weight used as a guide for very young infants. Ibuprofen guidance for children is set out by age band and by the strength of liquid in the bottle, which is another reason the strength printed on the label matters as much as the volume.

Most young children take liquid medicines, and measuring errors are a common source of harm. The NHS advises shaking the bottle for at least ten seconds before use, and using the oral syringe or spoon that comes with the medicine rather than a household spoon. Medicines for Children says kitchen teaspoons are discouraged because their sizes vary, and its guidance describes giving liquids by oral syringe, with or without a bung in the bottle neck.

Strength differs between products of the same medicine. An infant formulation and an older-child formulation of one painkiller can contain different amounts per millilitre, so the same volume is not interchangeable between them. Always read the strength on the bottle before measuring, and check again if someone else in the family has bought a different brand.

Medicines sold without prescription still have exclusions. NHS pages say paracetamol is unsuitable for a child who has had an allergic reaction to it or who has a kidney or liver condition. Ibuprofen is not recommended for children with asthma, kidney or liver conditions, chickenpox, pneumonia or a previous allergic reaction to anti-inflammatory painkillers.

Ibuprofen also carries a dehydration caution: if a child is vomiting, has diarrhoea or has a fever while taking it, the NHS advises speaking to a health professional about dehydration. These details are the reason pharmacists ask about a child's conditions and other medicines before recommending a product.

The NHS warns against giving paracetamol alongside other medicines that also contain it, such as cold and flu remedies, because the total can reach a harmful level. Alternating paracetamol and ibuprofen is something the NHS says should only be done when a health professional advises it. If a child has been given more paracetamol than the packet, leaflet or prescription says, the NHS advice is to ring NHS 111 straight away, and to have the packaging to hand.

Keeping a note of what was given and when, particularly when several adults share care, prevents most accidental repeats. All medicines, including those that look like sweets, should be stored out of sight and reach of young children.

Many medicines were first licensed for adults, and a prescriber may sometimes use a medicine in a child outside its licence or choose a specially prepared liquid. NHS Specialist Pharmacy Service guidance on swallowing difficulties describes licensed medicines, including those used off-label, as usually preferred over unlicensed specials, which gives a sense of how clinicians rank these options.

Off-label does not mean experimental. It means the product information does not list that age group or use, and the prescriber is relying on other evidence and professional references. If a label or leaflet seems not to match what has been prescribed, ask the pharmacist to explain rather than adjusting the dose yourself.

Medicines for Children has guidance and videos on the different ways children receive medicines, including inhalers, tablets and capsules, liquids by oral syringe, creams, eye drops, ear drops, nasal sprays, granules, powders, effervescent tablets, rectal medicines and tubes placed through the nose or stomach wall. Technique matters: a poorly used inhaler or a half-swallowed dose may deliver much less than intended.

Medicines for Children says its leaflets are written by paediatricians and pharmacists, checked by parents and carers, and reviewed regularly. The leaflets reference the British National Formulary for Children. A community pharmacist can explain labels and advise on over-the-counter products, and the NHS Yellow Card scheme accepts reports of suspected side effects from parents as well as professionals.