Published: March 2013

Publications

Children and Sedating Antihistamines

Prescriber Update 34(1):11-12
March 2013

Prescribers are reminded that 'first generation' or 'sedating' antihistamines are contraindicated for use:

• in children aged less than two years of age for all indications
• in children aged less than six years of age for coughs and colds.

The Cough and Cold Review Group in conjunction with Medsafe has previously found no evidence to support the use of sedating antihistamines in treating the symptoms of the common cold in children¹.

This reminder follows a report received by the Centre for Adverse Reactions Monitoring (CARM) concerning a three-year-old child who was given chlorphenamine for a lower respiratory tract infection and experienced a serious neurological disorder. Fortunately, the child eventually recovered without any on-going ill-effects.

Sedating antihistamines have the ability to cross the blood-brain barrier, the ability to bind to non-histamine receptors and have less selectivity for peripheral or central H1-receptors². Therefore, sedating antihistamines tend to cause more adverse reactions than 'second generation' or 'non-sedating' antihistamines².

The most common adverse effects with sedating antihistamines are sedation, dizziness and incoordination. However, paradoxical stimulation ranging from excitation through to tremors, hallucinations and convulsions may occur. Excessive doses in children have led to respiratory depression, coma and death^3,4.

With winter approaching, it is important to note that coughs and colds are often self-limiting conditions and may not require pharmacological intervention⁵. Symptomatic measures, such as increasing fluids, making sure children get enough rest and reducing the spread of the virus (including regular hand washing) should be practiced. For children requiring antihistamines for allergies, a non-sedating antihistamine such as loratadine or cetirizine is preferred.

References

1. Medsafe. 2009. Use of cough and cold medicines in children — New Advice. URL. www.medsafe.govt.nz/hot/alerts/coughandcold/infooct2009.asp (accessed 5 February 2013).
2. Ten Eick AP, Blumer JL, Reed MD. 2001. Safety of antihistamines in children. Drug Safety 24(2): 119-47.
3. Sanofi-Aventis NZ Limited. 2009. Promethazine Winthrop data sheet 31 January 2013. URL: www.medsafe.govt.nz/profs/Datasheet/p/PromethazineWinthropElixir.pdf (accessed 31 January 2013).
4. Douglas Pharmaceuticals Ltd. 2009. Histafen data sheet. 8 September 2009. URL: www.medsafe.govt.nz/profs/Datasheet/h/Histafenelixir.pdf (accessed 31 January 2013).
5. BPAC. 2010. Do cough & cold preparations work in children? Best Practice Journal 29: 32-39.