Australian data recently published by Bell et al highlight the importance of continued vigilance when it comes to medicines and children. According to the population-based study, approximately 27 children (under 5 years of age) are unintentionally exposed to pharmaceutical medicines every day in New South Wales. Of these, 250 children are admitted to hospital each year.1

The study incorporates data from NSW Poisons Information Centre (PIC) calls, emergency department (ED) presentations and hospital admissions for accidental pharmacological poisoning in children.1

Of the cases of accidental poisoning admitted to hospital, 75% occur in the home, These findings suggest there is still a role and a need for health professionals to discuss safe administration and home storage of medicines with their patients.1 

Paracetamol, not a magic cure

The most common substance category in PIC calls is ‘non-opioid analgesics, antipyretics and antirheumatics’, accounting for one in three cases of pharmacological poisoning.1

These accidental poisonings primarily involve medicines containing paracetamol (eg, Panadol, Panamax, Dymadon) and medicines containing ibuprofen (eg, Nurofen, Brufen, Advil). Accidental poisoning with these agents can occur in a variety of ways, including dosing errors and exploratory ingestion of syrups and tablets.

While therapeutic doses of paracetamol are safe, unintentional exposure at a high dose results in severe toxic effects. In fact, paracetamol overdose is the leading cause of paediatric acute liver failure in Australia and New Zealand, with another study showing that 14 of 54 cases of acute liver failure were attributed to paracetamol.2 These children received excess paracetamol for a variety of reasons, including too frequent administration, coadministration with other medicines containing paracetamol and prolonged administration of regular paracetamol doses (for a period of up to 24 days).2

Knowledge gaps among parents and carers of young children may contribute to unintentional misuse and overdose of paracetamol. Parents/carers may not be aware of:3-5

  • the risk of liver damage from a single acute overdose or from ongoing administration at supratherapeutic doses
  • appropriate indications for paracetamol use in children
  • different strengths and formulations, including why they should avoid adult-strength preparations in children
  • the fact that accidental exploratory ingestion is associated with most hospitalisations for paracetamol, highlighting the importance of safe storage.

Find out more about paracetamol for children

The risk with fentanyl patches 

Young children whose mothers have been prescribed opioids are at increased risk of overdose from opioids.6 While cases of opioid poisoning are infrequent in the 2018 Bell study,1 there have been two reports of accidental exposure of children to fentanyl patches in Australia. Both children were hospitalised.7

The risk of a partially detached patch being transferred from an adult to an infant is high, as infants are often held by adults.8

Toddlers explore their world by touching and tasting things within their reach. They are at increased risk of finding a patch that has been poorly stored or incorrectly disposed of and ingesting it or sticking it onto themselves. Used patches can retain high residual levels of the active ingredient (around 35% to 52% for higher doses and 90% for the 25 microgram-per-hour patch).8,9

If a fentanyl patch is chewed, a toxic dose may be released,10 with more than a 30-fold increase in absorption from the buccal mucosa if chewed, compared with the transdermal route.11

All health professionals should remind parents/carers to keep fentanyl patches out of reach of children and to correctly dispose of patches that have been used or are no longer needed. This involves folding the patch so that the adhesive side sticks to itself, before wrapping and carefully disposing of the patch. Unused patches should be returned to a pharmacy for safe disposal. If a fentanyl patch adheres to a child, advise the parent/carer to immediately remove it, and to phone the PIC or go to a hospital, as the child may still experience toxicity after removal.7,12

Adults who wear patches should consider covering the patch with an adhesive film to keep it on their body and regularly check that the patch is still in place, either by touch or by visual examination.

Parents/carers need to seek medical attention immediately if they suspect that a child may have ingested or been inadvertently exposed to a patch.7,12

Read more about accidental fentanyl exposure.

Oral syringes are more accurate than spoons

In the Bell et al study, for infants (aged < 1 year), 54.9% of cases of exposure reported to the PIC were defined as accidental ingestion, while 44.3% were defined as therapeutic error. In contrast, 87.2% of cases of poisoning for 1–5-year-olds were recorded as accidental ingestion.1 Developmental stages probably influence this, as infants are less mobile, while children aged 1–3 years are at high risk of accidental poisoning as they explore the world around them.13,14

Dosing errors are a major source of preventable poisoning. A US study examining how dosing errors could be reduced reported that up to 83.5% of parents make dosing errors, with 29.3% making ≥ 1 large error (ie, more than 2 × dose).15 Dosing errors are most commonly seen with cup and teaspoon-only labels compared with syringe and millilitre-only labels.15,16

While most parents currently prefer to see dosing instructions in millilitre (mL) units, some still prefer teaspoon units. However, the similarity of the abbreviations for teaspoons (tsp) and tablespoons (tbsp), can lead to confusion,17 and result in up to a 4-fold dosing error, considering one teaspoon is 5 mL and one tablespoon in Australia is 20 mL.

Evidence suggests that healthcare providers should encourage parents/carers to use an appropriately marked oral syringe to measure liquid medicines, particularly when small doses are recommended.16

This is especially significant for drugs with a narrow therapeutic index (NTIDs), such as clonidine, where there is a very small margin between a safe dose and a toxic dose.16,18

Clonidine is increasingly being used to treat attention deficit hyperactivity disorder and other behavioural disturbances in children.19 Children who receive a double dose of clonidine often require hospitalisation due to its narrow therapeutic range. Clonidine is the medicine most frequently requiring consultant clinical toxicologist input in this age group.20

Find out how to give medicine to children safely and accurately

Tips for health professionals to support parents and carers in administering medicines

1. Use metric dosing for prescribing and dispensing

Historically there have been a number of common errors in dosing, specifically confusion between millilitres and teaspoons. Before dispensing, pharmacists should double-check that the directions on the label match the original prescription.21

2. Prescribe, dispense and demonstrate with 5 mL or 10 mL syringes

When demonstrating how to draw up and administer medicine to a child, use 5 mL or 10 mL syringes and match the required dose to the appropriate sized syringe.15 Ensure the parent/carer understands how to read incremental markings; trial data suggest more errors in administration by carers occur with 2.5 mL and 7.5 mL dose amounts compared with 5 mL dose amounts.16  

3. Dispense and demonstrate administration with oral, not parenteral, syringes

At times children may be sent home with an IV cannula in place. Oral syringes have specially engineered hubs that cannot be easily or securely connected to standard IV lines, preventing accidental administration through the IV route. In addition, clearly demonstrate to the parent/carer that oral medicines are for oral use only.22

4. Use a combination of text and pictograms to support low health literacy

Adults with low health literacy may be more likely to find millilitre-dosing difficult. Evidence shows that demonstrating medicine dosage using a combination of text and pictograms results in fewer errors. This includes use of teachback/showback, drawings or pictures of the dose and dose demonstrations and providing dosing tools with millilitre units.15

5. Ensure parents/carers know that overdose and toxicity can occur with paracetamol

It is important that parents/carers are aware that despite being widely available without a prescription, paracetamol is a medicine and overdose can occur.23 Some reasons for overdose include dosing every 4 hours over a 24-hour period, resulting in six doses in total; more than one parent/carer administering medicine; and misreading the label.20

Many of the cases of accidental exposure to paracetamol reported to PIC occurred when a bottle was left on the bench or bedside table after dosing, or sometimes left with the cap off.20

When recommending paracetamol for pain relief in children and infants younger than 12 years of age, ensure that parents/carers know the following facts.23

  • Paracetamol comes in different formulations and strengths for different ages – choose the correct paracetamol product for the child's age.
  • They should keep track of all medicines that are given to the child. This helps prevent accidental overdose through coadministration of medicines that contain the same ingredient, for example paracetamol.16
  • There is a potential for liver damage with misuse and overdose of paracetamol, and there are no early signs of hepatotoxicity. Phone the PIC immediately if an overdose is suspected.
  • It is important to keep a current record of the child's weight. The recommended dose of paracetamol for children is based on ideal body weight (15 mg/kg).
  • The maximum recommended dosage for children, which is 15 mg/kg every 4–6 hours to a maximum of 1 gram, and no more than 4 doses in a 24-hour period, should never be exceeded.

6. Provide intensive support to families whose children are taking NTIDs

Drugs with a narrow therapeutic index (NTIDs) include clonidine, warfarin, carbamazepine, digoxin, phenytoin, tacrolimus and theophylline.18 For some NTIDs, errors within an even smaller range (< 20% deviation) may be clinically significant and additional intervention strategies are important to reduce errors.16 With infants, the millilitre dosing of these medicines can be less than 1 mL, so clear education with a 1 mL syringe is essential.

Advise on safe storage of all medicines

Incidences of exposure and poisoning in children are also strongly correlated with adult medicine prescriptions, with medicines affecting the cardiovascular system (such as statins, angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists) being common causes.1

Advise parents/carers to store ALL medicines out of reach of children. A locked cupboard at least 1.5 metres off the ground is a good place to store medicines. Also ensure that other family members, such as grandparents, do the same.12

Reinforce the safe storage message for ‘one pill can kill’ medicines including verapamil, diltiazem, sulfonylureas, anti-arrhythmics and opioids.20,24

Encourage carers to contact the local Poisons Information Centre

Calls to PICs have been shown to improve triage, allowing home management of many cases of unintentional exposure, thereby reducing the number of people entering the healthcare system as well as healthcare expenses.1

However, calls to the NSW PIC declined between 2008 and 2013, while emergency department presentations remained the same. Interestingly, presentations for less urgent poisoning cases increased, indicating that there were people going to hospital who might not have needed to if they had called a PIC.1

Australian PICs provide nationwide, round-the-clock specialist poisoning advice to healthcare professionals and members of the public. Encourage parents/carers to call the PIC on 13 11 26 if accidental exposure does happen, as their child may not necessarily need to go to hospital. 

Expert adviser

Dr Rose Cairns
Senior Poisons Specialist, New South Wales Poisons Information Centre
The Children's Hospital at Westmead

References

  1. Bell JC, Bentley JP, Downie C, et al. Accidental pharmacological poisonings in young children: population-based study in three settings. Clin Toxicol (Phila) 2018:1-8.
  2. Rajanayagam J, Bishop JR, Lewindon PJ, et al. Paracetamol-associated acute liver failure in Australian and New Zealand children: high rate of medication errors. Arch Dis Child 2015;100:77-80.
  3. King JP, Davis TC, Bailey SC, et al. Developing consumer-centered, nonprescription drug labeling a study in acetaminophen. Am J Prev Med 2011;40:593-8.
  4. Therapeutic Goods Administration. Labelling and packaging practices: A summary of some of the evidence. Woden, ACT, 2013 (accessed 26 March 2018).
  5. Graudins LV, Gazarian M. Promoting safe use of paracetamol in children. J Pharm Pract 2006;36:297-300.
  6. Finkelstein Y, Macdonald EM, Gonzalez A, et al. Overdose risk in young children of women prescribed opioids. Pediatrics 2017;139.
  7. Therapeutic Goods Administration. Medicines Safety Update, Volume 5, Number 4, August 2014. Woden, ACT, 2014 (accessed 2 February 2018).
  8. US Food and Drug Administration. Fentanyl patch can be deadly to children. Silver Spring, Maryland, 2013 (accessed 2 February 2018).
  9. Van Nimmen NF, Veulemans HA. Validated GC-MS analysis for the determination of residual fentanyl in applied Durogesic reservoir and Durogesic D-Trans matrix transdermal fentanyl patches. J Chromatogr B Analyt Technol Biomed Life Sci 2007;846:264-72.
  10. Carson HJ, Knight LD, Dudley MH, et al. A fatality involving an unusual route of fentanyl delivery: Chewing and aspirating the transdermal patch. Leg Med (Tokyo) 2010;12:157-9.
  11. Nelson L, Schwaner R. Transdermal fentanyl: pharmacology and toxicology. J Med Toxicol 2009;5:230-41.
  12. NPS MedicineWise. Accidental fentanyl exposure in children can be fatal. 2015 (accessed 12 February 2018).
  13. Meyer S, Eddleston M, Bailey B, et al. Unintentional household poisoning in children. Klin Padiatr 2007;219:254-70.
  14. Schmertmann M, Williamson A, Black D. Unintentional poisoning in young children: does developmental stage predict the type of substance accessed and ingested? Child Care Health Dev 2014;40:50-9.
  15. Yin HS, Parker RM, Sanders LM, et al. Pictograms, units and dosing tools, and parent medication errors: A randomized study. Pediatrics 2017;140.
  16. Yin HS, Parker RM, Sanders LM, et al. Liquid medication errors and dosing Tools: A randomized controlled experiment. Pediatrics 2016;138.
  17. Torres A, Parker RM, Sanders LM, et al. Parent preferences and perceptions of milliliters and teaspoons: Role of health literacy and experience. Acad Pediatr 2018;18:26-34.
  18. Tamargo J, Le Heuzey JY, Mabo P. Narrow therapeutic index drugs: a clinical pharmacological consideration to flecainide. Eur J Clin Pharmacol 2015;71:549-67.
  19. Ming X, Mulvey M, Mohanty S, et al. Safety and efficacy of clonidine and clonidine extended-release in the treatment of children and adolescents with attention deficit and hyperactivity disorders. Adolesc Health Med Ther 2011;2:105-12.
  20. Cairns R. Accidental poisoning in children clinical news story. Personal communication. 19 March 2018.
  21. Institute for Safe Medication Practices. Time for a change to metric. Horsham, Pennsylvania, 2006 (accessed 9 February 2018).
  22. Grissinger M. Oral syringes: making better use of a crucial and economical risk-reduction strategy. P T 2013;38:5-6.
  23. NPS MedicineWise. Safe and appropriate use of paracetamol: closing the consumer knowledge gap. 2015 (accessed 5 April 2018)..
  24. Matteucci MJ. One pill can kill: assessing the potential for fatal poisonings in children. Pediatr Ann 2005;34:964-8.