Paediatric Dental Doses (UK): Antibiotics, Analgesics and Local Anaesthetic by Age and Weight

Analgesics for children (paracetamol and ibuprofen)

Paracetamol is the first-line analgesic and antipyretic; ibuprofen can be added or used as an alternative where not contraindicated. Codeine and dihydrocodeine must not be used (see the codeine warning below).

Paracetamol — weight-based reference: 15 mg/kg per dose, maximum 1000 mg per single dose, every 4–6 hours, maximum 4 doses in 24 hours, with a minimum 4-hour gap between doses.

Ibuprofen — weight-based reference: 5–10 mg/kg per dose, maximum 400 mg per single dose, every 6–8 hours, maximum 4 doses in 24 hours. Daily ceiling: 30 mg/kg/day in children under 12 (SDCEP/BNFc), and 2.4 g/day in adolescents — this ceiling is enforced by the calculator. Take after food. Avoid in severe / aspirin-sensitive asthma, renal impairment, active peptic ulcer disease, or dehydration.

Antibiotics for children (dental infection)

Antibiotics are indicated for a child with a dental infection showing systemic involvement or spreading infection — they are not a substitute for removing the source (drainage, extirpation or extraction). First-line is amoxicillin; metronidazole is first-line for anaerobic involvement; azithromycin or cefalexin are penicillin-allergy alternatives.

Amoxicillin — first-line. TDS (three times daily) for 5 days. Take at regular intervals. Severe infection: doses can be doubled, or 30 mg/kg TDS (maximum 1 g) used.

Metronidazole — anaerobic / first-line alternative. Weight-based reference 7.5 mg/kg, for 5 days, single dose capped at 400 mg. Not licensed in children under 1 year. Avoid alcohol during the course and for 48 hours after.

Azithromycin — penicillin-allergy alternative. Once daily (OD) for 3 days. Weight-based: Day 1: 10 mg/kg, then 5 mg/kg on Days 2–3. Take 1 hour before or 2 hours after food.

Cefalexin — penicillin-allergy alternative (non-severe, no anaphylaxis). First-generation cephalosporin, BD (twice daily) for 5 days. Weight-based reference 12.5–25 mg/kg. Avoid in patients with a history of severe penicillin allergy / anaphylaxis (cross-reactivity risk).

Local anaesthetic for children

Children are dosed strictly by weight, with lower absolute ceilings than adults, and small errors are proportionally more dangerous. Calculate every paediatric LA dose from the child's weight, and in the medically compromised or adrenaline-limited patient the adrenaline (vasoconstrictor) load is often the limiting factor, not the anaesthetic mg. A standard UK dental cartridge is 2.2 ml.

The adrenaline-free local anaesthetic referenced here is prilocaine 3% with felypressin (Citanest with Octapressin; 6 mg/kg, ~300 mg cap, 66 mg per 2.2 ml cartridge), a valid UK adrenaline-free option that matches the in-app tool.

Codeine is contraindicated under 12 (MHRA 2013)

Estimating a child’s weight (when no scales are available)

Dose from the child's actual measured weight wherever possible. If weight is genuinely unavailable, the APLS UK weight-estimation formulae give an approximation only:

• Age 1–5 years: weight (kg) ≈ (age × 2) + 8
• Age 6–12 years: weight (kg) ≈ (age × 3) + 7

Estimated weight is a recognised source of dosing error. Treat it as a fallback, weigh the child where you can, and dose to the most conservative figure your reference supports.

How paediatric doses are calculated (method, not a recipe)

Paediatric doses are derived in two ways, and the safer of the two governs:

1. Age-band dose — look up the dose for the child’s age band (the tables above).
2. Weight-based dose — multiply the agent’s mg/kg by the child’s weight in kg, then apply the absolute cap / daily ceiling (e.g. paracetamol max 1 g/dose; ibuprofen 400 mg/dose and 30 mg/kg/day; metronidazole 400 mg/dose; lidocaine 320 mg and the 200 µg adrenaline ceiling). The lower figure always wins.
3. Confirm against the current BNFc / SDCEP and the individual child — reduce for low body weight, comorbidity, hepatic or renal impairment, and where adrenaline must be limited.

Worked illustration — a 5-year-old, estimated ~18 kg (APLS: 5 × 2 + 8 = 18 kg; for teaching only):

• Paracetamol: age-band dose 240 mg (4–5 years); weight-based 15 mg/kg × 18 = 270 mg, under the 1 g cap.
• Ibuprofen: age-band dose 150 mg TDS (4–6 years); 5–10 mg/kg × 18 = 90–180 mg; daily ceiling 30 mg/kg/day = 540 mg/day.
• Amoxicillin (if indicated): 500 mg TDS for 5 days (5–11 years band).
• Lidocaine 2% with 1:80,000: 5 mg/kg × 18 = 90 mg → 90 ÷ 44 = ~2.0 cartridges (weight-limited; well within the 200 µg adrenaline ceiling).

These are illustrative for one estimated weight and must be recalculated for the individual child.

Calculate a child-specific dose in Nosht

This page gives you the reference figures and the method. It does not output a dose for an individual child. For that, use the in-app Paediatric Doses tool: enter the child's age (and weight, or let it estimate weight with the APLS formulae) and pick the drug category (analgesic, antibiotic or local anaesthetic). It returns the age-band dose and the weight-based dose, applies the absolute caps and daily ceilings, flags the limiting factor (weight vs cap vs adrenaline ceiling), and surfaces safety warnings (under-1-year antibiotics, articaine under 4 years, very low weight, ibuprofen under 3 months / under 5 kg, codeine exclusion).

The Paediatric Doses calculator is deterministic and works from a fixed UK paediatric dental formulary dataset (BNFc / SDCEP-aligned) — it does not use a language model to generate doses, by design, for dose safety. Separately, Nosht's note-writing features optionally use clinician-reviewed AI (Anthropic Claude Haiku 4.5) to help structure clinical notes from your input; the clinical dose tools are deliberately not AI-generated.

What is the amoxicillin dose for a child with a dental infection?

For a child with a spreading or systemically involving dental infection, the first-line antibiotic is amoxicillin, three times daily (TDS) for 5 days: 125 mg TDS at 6–11 months, 250 mg TDS at 1–4 years, and 500 mg TDS at 5 years and over. In severe infection the dose can be doubled, or 30 mg/kg TDS (maximum 1 g) used. Antibiotics support, but do not replace, removing the source of infection. Verify against the current BNF for Children (BNFc) / SDCEP and the child's allergy status before prescribing.

What is the paediatric ibuprofen dose by weight?

Ibuprofen is dosed at 5–10 mg/kg per dose, every 6–8 hours, to a maximum of 400 mg per dose and a daily ceiling of 30 mg/kg/day in children under 12 (2.4 g/day in adolescents). Typical age-band doses are 50 mg TDS at 3–5 months (only if over 5 kg), 50 mg QDS at 6–11 months, 100 mg TDS at 1–3 years, 150 mg TDS at 4–6 years, 200 mg TDS at 7–9 years, 300 mg TDS at 10–11 years, and 300–400 mg QDS at 12–17 years. Give after food, avoid in asthma sensitive to NSAIDs, renal impairment, peptic ulcer disease or dehydration, and do not use under 3 months or under 5 kg.

What is the paracetamol dose for a child?

Paracetamol is 15 mg/kg per dose, every 4–6 hours, to a maximum of 1 g per dose and 4 doses in 24 hours, with at least a 4-hour gap between doses. Age-band doses are approximately 60 mg at 3–5 months, 120 mg at 6–23 months, 180 mg at 2–3 years, 240 mg at 4–5 years, 240–250 mg at 6–7 years, 360–375 mg at 8–9 years, 480–500 mg at 10–11 years, 480–750 mg at 12–15 years, and 500–1000 mg at 16+. Verify against the current BNFc.

Which antibiotic is used for a child who is allergic to penicillin?

For penicillin-allergic children, alternatives are azithromycin (once daily for 3 days — Day 1: 10 mg/kg, then 5 mg/kg on Days 2–3; from age 12+, 500 mg then 250 mg) or metronidazole for anaerobic involvement (50 mg TDS at 1–2 years, 100 mg BD at 3–6 years, 100 mg TDS at 7–9 years, 200 mg TDS at 10–17 years, single dose capped at 400 mg, for 5 days). Cefalexin (125–500 mg BD by age) may be used for non-severe penicillin allergy without anaphylaxis, but is avoided where there is a history of severe penicillin allergy. Confirm the nature of the allergy and verify against the current BNFc / SDCEP.

What is the maximum local anaesthetic dose for a child?

Children are dosed strictly by weight with lower absolute ceilings, so there is no single number. A commonly used paediatric figure for lidocaine 2% with 1:80,000 adrenaline is 5 mg/kg, to an absolute cap of 320 mg, and also limited by a 200 µg adrenaline ceiling (about 7 cartridges of 1:80,000; each 2.2 ml cartridge contains 44 mg lidocaine and 27.5 µg adrenaline). Articaine 4% (7 mg/kg; cap 385 mg ages 4–11, 88 mg/cartridge) is generally avoided under 4 years. Prilocaine 3% with felypressin (6 mg/kg; cap ~300 mg) is an adrenaline-free option. Calculate from the child's weight and verify against the BNF for Children (BNFc) / DPF.

Can children have codeine for dental pain?

No. Following the MHRA Drug Safety Update (June 2013), codeine is contraindicated in children under 12 years, and codeine and dihydrocodeine must not be used for paediatric dental pain. Use paracetamol ± ibuprofen instead.