Section 1: Introduction -- The Dose That Was Right for an Adult

A 3-year-old boy in Bridgetown, Barbados is brought to the emergency department following a seizure. His mother had given him paracetamol liquid for fever. She had used a regular tablespoon to measure the dose because she could not find the dosing syringe that came with the bottle. A regular tablespoon holds approximately 15 mL. The recommended dose for his weight was 5 mL. He received three times the correct dose, repeatedly.

Paediatric medicine errors arise most commonly not from prescribing the wrong drug but from prescribing or administering the wrong dose for the child's weight -- or from failing to recognise that a drug safe in adults is contraindicated or dangerous in children.

Children are not small adults. They have different pharmacokinetics at every developmental stage: neonates have immature hepatic enzyme systems; infants have proportionally higher body water content; toddlers may have faster renal clearance per kilogram than adults; and adolescents are neither children nor adults in their drug metabolism profiles. A dose that is appropriate for one age group can be toxic in another.

Caribbean paediatric prescribing has five specific challenges this report addresses:

Weight-based dosing errors. Most paediatric drugs are dosed by body weight. Errors arise from using the wrong weight (estimated rather than measured), wrong concentration (particularly with liquid formulations that come in multiple strengths), wrong measuring device (household spoons instead of the provided syringe or measure), and wrong frequency.

Contraindicated drugs in children. A number of commonly prescribed or OTC drugs are contraindicated at specific ages: aspirin (Reye syndrome), tetracyclines (teeth and bone), fluoroquinolones (cartilage), chloramphenicol (grey baby syndrome in neonates), codeine (respiratory depression, particularly in CYP2D6 ultra-rapid metabolisers). These contraindications are frequently violated in Caribbean primary care.

Caribbean herbal remedies in children. Cerasee (Momordica charantia) tea is routinely given to infants and young children across the Caribbean for a range of conditions. It contains compounds with hypoglycaemic and abortifacient properties. Other herbals -- including teas made from dubious botanical sources -- are given to children on the basis of traditional practice, without awareness of pharmacological risk.

OTC medicine misuse. Over-the-counter cough and cold preparations containing antihistamines (promethazine, diphenhydramine), decongestants (pseudoephedrine), and codeine-containing syrups are dangerous in children under 6 years. Promethazine is contraindicated under 2 years due to the risk of fatal respiratory depression. These products remain available in some Caribbean pharmacies.

Antibiotic dosing in children. Amoxicillin and other antibiotics are prescribed for children at flat doses (e.g., "one teaspoon three times daily") without reference to weight. For a 4-year-old weighing 16 kg, one teaspoon (5 mL of 125 mg/5 mL suspension = 125 mg) is substantially under-dosed; the correct dose at 45 mg/kg/day is 720 mg/day.

Section 2: Paediatric Pharmacokinetics -- Why Children Are Different

2.1 Absorption

Gastric pH is higher in neonates and infants than in adults, affecting the absorption of acid-labile drugs. Gastric emptying is slower in neonates. Intramuscular absorption is variable in neonates due to lower muscle mass and blood flow.

Skin absorption is proportionally higher in neonates due to a thinner stratum corneum and a higher surface area to body weight ratio. Topical drugs -- including corticosteroids and antiseptics -- produce higher systemic exposure in neonates than in adults.

2.2 Distribution

Total body water is proportionally higher in neonates (75-80% of body weight vs 60% in adults), increasing the volume of distribution for water-soluble drugs. Plasma protein binding is reduced in neonates (lower albumin; fetal albumin binds drugs less avidly), increasing the free fraction of highly protein-bound drugs.

2.3 Metabolism

Hepatic enzyme systems mature at different rates. CYP3A4 is present but lower in neonates; activity approaches adult levels by 6-12 months. CYP1A2 is very low at birth and matures slowly. Phase II enzymes (glucuronidation, sulphation) are similarly immature.

The clinical implication: drugs that are hepatically metabolised may have prolonged half-lives in neonates and young infants. Morphine, chloramphenicol, and diazepam all have substantially prolonged effects in neonates.

2.4 Excretion

Renal function -- glomerular filtration and tubular secretion -- is low at birth and matures rapidly over the first 2 years. GFR at birth is approximately 25-30% of adult values (adjusted for body surface area). Renally excreted drugs may accumulate in neonates and young infants.

Section 3: Contraindicated and Age-Restricted Drugs

3.1 Aspirin -- Reye syndrome

Aspirin is contraindicated in children and adolescents under 16 years with viral illnesses. Reye syndrome -- a rare but potentially fatal condition causing acute liver failure and encephalopathy -- is associated with aspirin use in children during viral infections, particularly influenza and varicella.

Aspirin should not be used as an antipyretic or analgesic in children. Paracetamol and ibuprofen are the appropriate alternatives.

3.2 Tetracyclines -- teeth and bone

Tetracyclines (doxycycline, minocycline, tetracycline) bind to calcium and are incorporated into developing teeth and bone. They cause permanent yellow-grey staining of primary and secondary teeth and can impair bone growth.

Contraindicated in children under 8 years and in pregnancy (Report 5). Exception: doxycycline is permitted in children under 8 for specific life-threatening indications (rickettsial diseases, anthrax) where no alternative exists.

3.3 Fluoroquinolones -- cartilage

Fluoroquinolones (ciprofloxacin, levofloxacin) have been associated with cartilage damage in weight-bearing joints in animal studies. They are not routinely used in children and are generally avoided below 18 years except for specific indications (cystic fibrosis, multidrug-resistant infections) where no alternative exists.

3.4 Codeine -- respiratory depression

Codeine is a prodrug metabolised to morphine by CYP2D6. In ultra-rapid CYP2D6 metabolisers (a genetic variant that produces disproportionate morphine from codeine), the result can be life-threatening respiratory depression.

The FDA, EMA, and Health Canada have contraindicated codeine for pain relief in children under 12 years and in any patient under 18 years following tonsillectomy or adenoidectomy (where opioid sensitivity may be elevated). Several fatal cases in children occurred from codeine prescribed post-operatively.

Codeine-containing cough syrups remain available in some Caribbean pharmacies. These should not be dispensed to children.

3.5 Chloramphenicol -- grey baby syndrome

Chloramphenicol is metabolised by glucuronidation in the liver. This pathway is immature in neonates. Chloramphenicol accumulates to toxic levels, causing grey baby syndrome: abdominal distension, vomiting, ashen grey colour, circulatory collapse, and death. Chloramphenicol is contraindicated in neonates except in life-threatening situations with therapeutic drug monitoring.

3.6 Promethazine -- respiratory depression in young children

Promethazine (an antihistamine/antiemetic) is contraindicated in children under 2 years. It can cause fatal respiratory depression in infants. The FDA, EMA, and Health Canada have issued warnings. Promethazine-containing OTC products remain available in some Caribbean markets.

3.7 NSAIDs in neonates

NSAIDs are contraindicated in neonates (except indomethacin/ibuprofen for closure of patent ductus arteriosus in specialist settings) due to impaired renal function and the risk of acute kidney injury and enterocolitis.

Section 4: Paracetamol -- The Right Drug, the Wrong Dose

Paracetamol (acetaminophen) is safe and effective in children when correctly dosed. It is also the most common drug involved in paediatric accidental overdose.

4.1 Correct dosing

Dose: 15 mg/kg per dose (some guidelines allow 10-15 mg/kg), every 4-6 hours, maximum 4 doses in 24 hours. Maximum daily dose: 60 mg/kg/day or 1 g/dose (whichever is lower), not exceeding adult maximum of 4 g/day.

4.2 Concentration confusion

Paracetamol liquid comes in multiple concentrations in Caribbean pharmacies: 120 mg/5 mL (paediatric) and 250 mg/5 mL (stronger paediatric, or adult-weight children). Using the 250 mg/5 mL formulation with a dose measured for the 120 mg/5 mL formulation produces a dose more than double the intended amount.

The clinical instruction: Always check the concentration on the bottle before calculating the dose in mL. Volume-based instructions (e.g., "give 5 mL") are meaningless without specifying which concentration.

4.3 Measuring devices

Household teaspoons and tablespoons are not standardised. Studies show household spoons measure between 2.5 and 9 mL when nominally measuring 5 mL. The correct measuring device is the oral syringe or dosing cup provided with the medicine, using the volume calculated for the specific concentration being used.

Section 5: Antibiotic Dosing in Children -- Weight-Based, Not Flat

5.1 Amoxicillin

Standard dose: 40-45 mg/kg/day in three divided doses (or two divided doses for specific indications). High-dose (for resistant pneumococcus, acute otitis media): 80-90 mg/kg/day.

Common formulation: 125 mg/5 mL or 250 mg/5 mL suspension.

The most common error in Caribbean practice: prescribing a flat dose ("one teaspoon three times daily") regardless of weight. For a 20 kg child, 5 mL of 125 mg/5 mL = 125 mg per dose = 375 mg/day. The correct dose is 800-900 mg/day. The child is being under-dosed by more than half.

5.2 Other commonly used antibiotics

Section 6: OTC Medicines and Traditional Remedies -- The Caribbean-Specific Dangers

6.1 Cough and cold preparations

Cough and cold preparations containing antihistamines (promethazine, diphenhydramine, chlorphenamine), decongestants (pseudoephedrine, phenylephrine), and expectorants are not effective in children under 6 years for their stated indications and carry risks of adverse effects including sedation, hallucinations, tachycardia, and respiratory depression.

The EMA and FDA have recommended that OTC cough and cold preparations should not be used in children under 6 years. Most regulatory bodies have extended this to under 12 years for preparations containing promethazine.

In Caribbean practice, these products are widely used in infants and toddlers, often at doses extrapolated from adult use. The evidence for benefit does not support this practice.

6.2 Cerasee tea (Momordica charantia)

Cerasee (bitter melon) is a traditional Caribbean plant medicine. Cerasee tea is given to infants from birth in some communities for colic, fever, "cleansing," and various symptoms.

Pharmacological concerns: - Hypoglycaemia: Momordica charantia contains compounds with insulin-like activity. Administration to neonates and infants can cause profound hypoglycaemia. - Abortifacient compounds: In pregnant women, cerasee has documented uterotonic activity. This is less directly relevant to paediatrics but relevant to adolescents. - Drug interactions: The hypoglycaemic effect is additive with antidiabetic drugs in older children with type 1 or type 2 diabetes.

Clinicians should ask specifically about cerasee use at every paediatric consultation, particularly for infants. Parental education should be provided in a respectful, culturally informed manner.

6.3 Other traditional Caribbean preparations for children

Bush teas made from a range of plants are given to children across the Caribbean. Many are pharmacologically active. Without knowing the botanical composition, the dose, or the preparation method, pharmacological prediction is not possible. The clinical approach is to ask, to record, and to counsel where specific risks are known.

Section 7: Common Paediatric Prescribing Errors -- A Reference Table

Section 8: The Paediatric Prescribing Checklist

Section 9: About ElesRx

ElesRx includes age-related contraindication flags for paediatric prescribing. When a drug is prescribed with a patient age on record, the system alerts on aspirin under 16, codeine under 12, tetracyclines under 8, and promethazine under 2. The system also includes weight-based dose range checks for commonly prescribed paediatric medicines.

The tool is available at elesrx.com. ElesRx is a product of PIPPS Smart Apps, a division of J.C. Epiphany Limited (Jamaica, est. 1998).

Section 10: Methodology and References

10.1 Data sources

Paediatric prescribing data is drawn from the ElesRx clinical database, DailyMed, the European Medicines Agency, Health Canada, the British National Formulary for Children (BNFc), and the World Health Organization Model Formulary for Children.

10.2 Limitations

Neonatal intensive care pharmacology, paediatric oncology pharmacotherapy, and specialist paediatric anaesthetic drug use are beyond this report's scope. Doses provided are guidance references; prescribers should verify against current local formulary guidelines and individual patient factors.

10.3 Author and conflict of interest disclosure

This report was authored by Juliet Duncan, BPharm, founder of J.C. Epiphany Limited and developer of ElesRx. The author has a commercial interest in ElesRx. This report is published without an access gate as a contribution to Caribbean clinical education. No external funding was received.

10.4 Citation

Duncan J. The Paediatric Prescribing Report: Children Are Not Small Adults. ElesRx Clinical Reports, Report 24. Prepared June 2026. Published 2027 at elesrx.com/reports/paediatric-prescribing-report/. J.C. Epiphany Limited, Jamaica.

References

1. FDA Drug Safety Communication. FDA recommends against the use of codeine pain and cough medicines in children; recommends limitations on use in breastfeeding women. US Food and Drug Administration. 2017.

2. European Medicines Agency. Codeine-containing medicines: EMA recommends restricted use in children. EMA. 2013.

3. WHO. Model Formulary for Children 2010. World Health Organization. 2010.

4. Gonzalez-Valcarcel J, Steinberg JA. Medications of concern in neonates and young infants. Pediatr Rev. 2012;33(12):e97-e105.

5. Lans C, Turner N, Khan T, Brauer G. Ethnoveterinary medicines used for ruminants in British Columbia, Canada. J Ethnobiol Ethnomed. 2007;3(1):11. doi:10.1186/1746-4269-3-11