Compare before deciding: Noise phobia – dexmedetomidine vs. imepitoin

About noise phobia

  • Many types of noise are reported to cause significant anxiety and fear problems in dogs. They include thunderstorms, gunshots and traffic noise. In the UK the most commonly-reported cause is fireworks. Symptoms of noise phobia include restlessness, panting, vocalisation, cowering, trembling, frequent elimination, destructive behaviour, inappetence, owner-seeking behaviour and escape behaviours such as bolting. (Mills 2005; Sherman & Mills 2008; PDSA Paw Report 2011; Blackwell et al 2013; Storengen & Lingaas 2015). 

    Treatment of noise phobia requires a good understanding of the fear response and, in each case, the predisposing, initiating and maintaining factors. Interventions include behavioural therapies such as environmental changes, owner education, desensitisation and counter-conditioning. (Mills 2005)

  • Behavioural therapies may be supported by adjunctive therapies including dog-appeasing pheromone, nutritional supplements, herbal remedies and drugs. Potential drug treatments include oral anxiolytics and antidepressants, such as alprazolam and propranolol (both unlicensed in dogs), and clomipramine, fluoxetine and selegiline (which are licensed for the treatment of behavioural disorders in dogs, but not specifically noise aversion) (Mills 2005). 

  • There are currently two drug treatments specifically licensed for treating noise aversion in dogs: dexmedetomidine oromucosal gel (Sileo) and imepitoin (Pexion). Below we have summarised the key facts about the two medicines, to help with choice. To see the full reviews of each product, following the links: dexmedetomidine; imepitoin.

How do the two licensed treatments compare?


*NOTE: to our knowledge the two drugs have not been compared in the same trial, and so these figures are not reliable indicators of relative efficacy.

**Based on list prices. Thanks to Vetcel for providing these.


Dexmedetomidine and imepitoin have not been compared directly in a randomised controlled trial and so we do not know their relative efficacy. On indirect evidence, they appear to be similarly effective. The drugs have similar contraindications but a different range of adverse effects. The immediate action of dexmedetomidine makes it more suitable than imepitoin for use during unexpected noise events. However dexmedetomidine is more expensive and there is more information to convey to the client about correct use, although there are helpful instructions in the package leaflet and in a video. The two drugs have different modes of action, so if one is not sufficiently effective, or the adverse effects are intolerable, it is probably worth trying the other.


Blackwell EJ et al. (2013) Fear responses to noises in domestic dogs: prevalence, risk factors and co-occurrence with other fear related behaviour. Applied Animal Behaviour Science 145(1): 15

BSAVA Small Animal Formulary: Canine and Feline. 9th edition (2017) Ramsey I, editor.

Committee for Medicinal Products for Veterinary Use (CVMP) (2015). CVMP assessment report for Sileo (EMEA/V/C/003764/0000) International non-proprietary name: dexmedetomidine [online]. [Accessed 30.04.19]

Committee for Medicinal Products for Veterinary Use. CVMP assessment report for a grouped type II variation for Pexion, May 2018. Available: [Accessed 13.2.2019]

Engel O et al. (2018) Imepitoin shows benzodiazepine-like effects in models of anxiety. Frontiers in Pharmacology 9: 1225 

McPeake KJ & Mills DS. (2017) The use of imepitoin (Pexion) on fear and anxiety-related problems in dogs – a case series. BMC Veterinary Research 13:173

Korpivaara M et al. (2017) Dexmedetomidine oromucosal gel for noise-associated acute anxiety and fear in dogs – a randomised, double-blind, placebo-controlled clinical study. Vet Record 180: 356

McPeake K et al. (2017) Noise sensitivities in dogs: a new licensed treatment option. Vet Record 180: 355

McPeake KJ & Mills DS. (2017) The use of imepitoin (Pexion) on fear and anxiety-related problems in dogs – a case series. BMC Veterinary Research 13:173

Mills D (2005) Management of noise fears and phobias in pets. In Practice 27: 248–55

Packer R et al. (2017) Investigating the potential of the antiepileptic drug imepitoin as a treatment for co-morbid anxiety in dogs with idiopathic epilepsy. BMC Veterinary Research 13: 90

PDSA and YouGov. PDSA Animal Wellbeing (PAW) Report (2011) The State of Our Pet Nation. Available from:

Pexion 100mg, 400mg tablets. Summary of product characteristics. Boehringer Ingelheim Vetmedica GmbH, November 2017. [Accessed 13.2.2019]

Plumb’s Veterinary Drugs [online]. [Accessed 30.04.19]

Rundfeldt C et al. (2014) Imepitoin as novel treatment option for canine idiopathic epilepsy: pharmacokinetics, distribution and metabolism in dogs. Journal of Veterinary Pharmacology and Therapeutics 37: 421–34

Rundfeldt C & Loscher W (2014) The pharmacology of imepitoin: the first partial benzodiazepine receptor agonist developed for the treatment of epilepsy. CNS Drugs 28: 29–43

Sherman BL & Mills DS (2008) Canine anxieties and phobias: an update on separation anxiety and noise aversion. Veterinary Clinics of North America: Small Animal Practice 38: 1081-106

Sileo 0.1mg/mL oromucosal gel for dogs. Summary of product characteristics. Orion Corporation, June 2015. Available: [Accessed 10.4.19]

Storengen LM & Lingaas F (2015) Noise sensitivity in 17 dog breeds: prevalence, breed risk and correlation with fear in other situations. Applied Animal Behaviour Science 171: 152-60.

Veterinary Prescriber 2019. Imepitoin for noise aversion in dogs. April 

Veterinary Prescriber 2019. Dexmedetomidine for noise aversion in dogs. July.

Veterinary Prescirber 2016. Fireworks: can alpha-casozepine help? 2016

Waller, Sampson AP, Renwick AG et al, editors (2014). Medical pharmacology and therapeutics. Saunders Elsevier.