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;
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 If amantadine is withdrawn from these patients, it will be challenging to find alternative medications to prevent suffering in these pets.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
I am based in the Uk and for 8 months between July 2021 and March 2022, my geriatric dog was on a combination of Amantadine, acetaminophen and Metacam, to treat severe pain. She has hip and elbow dysplasia, along with severe OA, which has progressed to every joint in all legs.
We have prescribed this combination whilst we waited for a new medication on the market to become available, but there were supply issues. By December 2021, I didn't think I would get another 3 months with my dog, she couldn't stand to eat her food, had to be carried up/down stairs and refused to go on even short walks around the estate. Then, at the start of April this…
This is highly concerning. I understand this drug is used also as an anti-viral, however, the key functions medical veterinarians have are: to prevent and avoid animal suffering and to diagnose and give information (everything else is an extra). From my point of view I, Josue Garcia Ruiz, BVSc, MRCVS and currently on a PGCert-SAS, think that each medication should be given according to each case and used within a logic, if in the veterinary profession we use this drug mainly as an analgesic when other drugs fail to do so, then there shouldn't exist doubt about our criteria for its use.