EU propose restricting amantadine from vets

There is an EU proposal out for consultation currently, looking at restricting amantadine for human use, the rationale being that it is an anti-viral that should be reserved for human treatment. This proposal is contained within another regarding anti-microbial restrictions.

To date I have responded to this on behalf of the European College of Veterinary Anaesthesia & Analgesia. The Association of Veterinary Anaesthetists will also submit a response.

I have posted my response here and you are very welcome to adapt and use. The link to reply to this consultation is;

https://ec.europa.eu/info/law/better-regulation/have-your-say/initiatives/11653-Drug-resistance-list-of-antimicrobial-medicines-reserved-for-treating-humans_en

We write with concern of a developing welfare issue should amantadine be restricted to human use. A number of dogs and cats are treated with amantadine for chronic pain. If amantadine is withdrawn from these patients, it will be challenging to find alternative medications to prevent suffering in these pets.

There are currently no licensed veterinary medicines for the treatment of central sensitisation, a key feature of chronic pain in dogs and cats. Amantadine acts at the NMDA receptor at the level of the spinal cord to reduce central sensitisation and thus reduce hyperalgesia associated with pain.

[Hyperalgesia = Increased pain from a stimulus that normally provokes pain]

[Central sensitisation = Increased responsiveness of nociceptive neurons in the central nervous system to their normal or subthreshold afferent input]

Definitions taken from International Association for the Study of Pain

The evidence for the use of amantadine in dogs originated from a study of osteoarthritic dogs that were refractory to non-steroidal anti-inflammatory treatment. After 21 days treatment with amantadine and meloxicam these dogs were more active and less lame compared to dogs treated with meloxicam alone (Lascelles et al 2008). These authors concluded ‘in dogs with osteoarthritic pain refractory to an NSAID, physical activity is improved by the addition of amantadine’.

A study in cats by Shipley et al (2021) documented improved owner-assessed mobility and quality of life in cats with osteoarthritis. To facilitate easy dosing for cats, a veterinary specific formulation of amantadine is available (Bova UK, Summit UK).

Various authors consider amantadine an important addition to pharmaceutical options for chronic pain management. Rychel (2010) includes amantadine in recommendations for managing dogs with osteoarthritis. In a review of neuropathic pain in dogs, Moore (2016) includes the use of amantadine based on a publication by Madden et al (2014). Information on the use of amantadine in dogs and cats is available for veterinary practitioners at www.zeropainphilosophy.com.

As European Specialists in Pain Management, we urge you to reconsider this decision on the basis of the suffering that can be prevented through the use of amantadine.

References

International Assoc for the Study of Pain

https://www.iasp-pain.org/resources/terminology/#pain

Lascelles BD, Gaynor JS, Smith ES, Roe SC, Marcellin-Little DJ, Davidson G, Boland E, Carr J. Amantadine in a multimodal analgesic regimen for alleviation of refractory osteoarthritis pain in dogs. J Vet Intern Med. 2008 Jan-Feb;22(1):53-9. doi: 10.1111/j.1939-1676.2007.0014.x. PMID: 18289289.

Madden M, Gurney M, Bright S. Amantadine, an N-Methyl-D-Aspartate antagonist, for treatment of chronic neuropathic pain in a dog. Vet Anaesth Analg. 2014 Jul;41(4):440-1. doi: 10.1111/vaa.12141. Epub 2014 Mar 28. PMID: 24673830.

Moore SA. Managing Neuropathic Pain in Dogs. Front Vet Sci. 2016 Feb 22;3:12. doi: 10.3389/fvets.2016.00012. PMID: 26942185; PMCID: PMC4762016.

Rychel JK. Diagnosis and treatment of osteoarthritis. Top Companion Anim Med. 2010 Feb;25(1):20-5. doi: 10.1053/j.tcam.2009.10.005. PMID: 20188335.

Shipley H, Flynn K, Tucker L, Wendt-Hornickle E, Baldo C, Almeida D, Allweiler S, Guedes A. Owner evaluation of quality of life and mobility in osteoarthritic cats treated with amantadine or placebo. J Feline Med Surg. 2021 Jun;23(6):568-574. doi: 10.1177/1098612X20967639. Epub 2020 Oct 28. PMID: 33112193.

I would very grateful if you wish to contribute.

Thanks,

Matt