2020/01/10 A case report of applying an orexin receptor antagonist to sleep disorders in elderly dogs
A case report of applying an orexin receptor antagonist to sleep disorders in elderly dogs
Animal Medical Center of Gotemba Inter, Gotemba, Shizuoka, Japan.
Although the aging of pets has recently become a social topic, there has been no remarkable change in the aging of pets compared with that in 10 years ago, according to the data from the “National Pet Owner Survey” by the Japan Pet Food Association. However, the veterinarians engaged in small animal clinical practice feel that they have had more occasions to see elderly pets than before. According to 2018 Anicom White Paper, the number of dogs that have insurance at the age of 12 (the oldest in the data) is more than six times that of 10 years ago, which may reflect our feelings. Since those pets have aged through the period in which the quality of breeding improved, veterinary medicine developed, and living environment improved, their health states have been managed on some levels when they visit hospitals. Therefore, it is likely that elderly pets of a new generation presenting with diseases such as sarcopenia/flail and dementia are visiting veterinary hospitals, similar to the situation in human elderly medicine. Here we report the application of a new drug, orexin receptor antagonist, to sleep disorder in dogs associated with aging, which is one of the major causes of anxiety for the owners of dogs belonging to such new-generation elderly pets.
Orexin receptor antagonist (pharmaceutical name: Belsomra) is a new drug discovered and developed by Japanese researchers of MSD in 2014. Belsomra blocks the binding of orexin to its receptors to suppress excessively active wakefulness system, thereby causing the brain to transition from a physiological wakefulness to a sleep state and allow natural sleeps. Seventeen patient dogs aged 13-20 years presenting with sleep disorders (night bark, day/night reversal, wandering, breathing disorder, etc.), which visited our hospital, were administered with 2-5 mg/kg Belsomra once or twice a day. Thirteen of them were complicated with heart (n = 8) or kidney (n = 8) disease, or diabetes (n = 3), including overlapping, and four of them received single administration. Fourteen out of 17 dogs showed improved sleep with which owners were satisfied, but no significant effect was observed in three dogs. Seven out of 14 dogs that showed the improvement stopped taking the drug within 30 days, while four switched to its temporary use only when symptoms were severe, and three required its continuous use. Angiotensin receptor antagonist was effective for one of the three patient dogs for which Belsomra was not effective. In other dogs, angiotensin receptor antagonist was sometimes effective but not in other times.
In small animal clinical practice, GABA receptor agonists are mainly used for sleep disorders in dogs. However, side effects such as wamble and respiratory depression sometimes prevent their use for elderly dogs and also impose mental burdens to owners. Belsomra allows relatively clear awakening from high-quality sleeps and walking after wakeup even for elderly dogs. Therefore, Belsomra prevents elderly dogs from becoming bedridden and is easier to use in veterinarian medicine for elderly dogs complicated with heart or kidney disease compared to GABA receptor agonists.
Orexin receptor antagonist is a new drug developed for sleep disorders in human; thus, there is not sufficient information of indication available in the veterinary field. Nevertheless, Belsomra used in these cases is considered to be a highly effective sleep disorder ameliorating drug available in small animal clinical practice. Its indication requires adequately informing owners as well as careful administration, because it is a new drug.
orexin orexin receptor antagonist Belsomra sleep disorders elderly dog sarcopenia flail dementia