Important aspects of prescribing information relevant to primary healthcare are covered in this section specifically for the drugs recommended in this CKS topic. For further information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://emc.medicines.org.uk), or the British National Formulary (BNF) (www.bnf.org).

• True penicillin allergy: do not use amoxicillin. The following do not constitute an allergy to penicillin:
• Gastrointestinal adverse effects alone (e.g. nausea, vomiting, or diarrhoea).
• Erythematous, maculopapular rash in a child with glandular fever.

• Amoxicillin is usually well tolerated but nausea, vomiting, or diarrhoea can sometimes occur.
• Amoxicillin causes a rash in some people, but this may not always mean that they are allergic to penicillin. If the child gets a rash, stop giving the amoxicillin and seek medical advice to obtain alternative treatment, and so that the doctor can see the rash and determine whether penicillin allergy is likely or not.

• There are several clinically important drug interactions with erythromycin and clarithromycin.
• Possible enhanced effect of theophylline and carbamazepine (due to cytochrome P450 enzyme inhibition). Check levels of these drugs if adverse effects occur or worsen.
• The risk of significant interactions is probably smaller with clarithromycin than with erythromycin, but is still present.

• Macrolides commonly cause gastrointestinal adverse effects (e.g. nausea, vomiting, diarrhoea).
• If the child has had problems with gastrointestinal adverse effects in the past when taking erythromycin, it may be worth using clarithromycin instead, as it usually has milder gastrointestinal adverse effects.

• Asthma: do not give ibuprofen to children in whom attacks of asthma are known to have been precipitated by a nonsteroidal anti-inflammatory drug (NSAID).
• History of hypersensitivity to aspirin or other NSAIDs: do not use ibuprofen.

• Paracetamol and ibuprofen rarely cause adverse effects when used for short-term treatment.
• Paracetamol has no notable adverse effects when used at the correct dosage.
• Ibuprofen may sometimes cause gastrointestinal adverse effects (e.g. discomfort, nausea, diarrhoea), and occasionally causes wheeze in some people.