References

1. NHS choices: Allergies https://www.nhs.uk/conditions/allergies/ accessed on 26.03.2018

2. Allacan® Summary of Product Characteristics

3. Allacan® Patient information leaflet

4. NICE Clinical Knowledge Summaries (2015) Allergic rhinitis

5. Scadding G, GPonline 2017, Hay fever: clinical review accessed on 26.03.2018

6. Zhang L et al. The clinical use of cetirizine in the treatment of allergic rhinitis, Pharmacology 2013; 92:14-25