Pyridoxine

From Dog

Pyridoxine (3-hydroxy-4,5-dihydroxy-methyl-2-methyl-pyridine; Vitamin B6) is an essential vitamin important for epidermal barrier function[1], neuronal metabolism[2], hemosynthesis as well as homeostasis of Na:K levels.

Pyridoxine is one form of vitamin B6, a group of water-soluble, structurally related compounds that also includes pyridoxal and pyridoxamine. These forms are about equally active and are readily interconvertible[3]. Dogs convert pyridoxine into the enzymatically active form, pyridoxal-5-phosphate, which plays a role in a wide variety of enzyme systems, especially in the metabolic utilization and transformation of amino acids.

Deficiencies result in microcytic hypochromic anemia, skin lesions and seizures[4].

Pyridoxine in excess levels (> 150 mg/kg daily for 7 days) is associated with development of a reversible neuropathy in dogs characterized by weight loss, proprioceptive deficits[5] and hindlimb ataxia[6][7].

This drug is primarily used as an adjunct treatment of anemia as well as a supportive drug in cognitive dysfunction syndrome[8] and treatment of side-effects associated with chemotherapy (e.g. isoniazid[9], doxil[10]).

Recommended daily dose for dogs is 1.0 - 2.0 mg/kg orally or subcutaneously.

References

  1. Watson AL et al (2006) Dietary constituents are able to play a beneficial role in canine epidermal barrier function. Exp Dermatol 15(1):74-81
  2. Bahn JH et al (2002) Immunohistochemical studies of brain pyridoxine-5'-phosphate oxidase. Brain Res 925(2):159-168
  3. Brin, M (1978) Vitamin B6-Chemistry, absorption, metabolism, catabolism and toxicity. In:Human Vitamin B6 Requirements-Proceedings of a Workshop, pp. 1-20. National Academy of Sciences, Washington
  4. Rosenberg IH (2012) A history of the isolation and identification of vitamin B(6). Ann Nutr Metab 61(3):236-238
  5. Chung JY et al (2008) Pyridoxine induced neuropathy by subcutaneous administration in dogs. J Vet Sci 9(2):127-131
  6. Chung JY et al (2008) In vitro and in vivo gene therapy with CMV vector-mediated presumed dog beta-nerve growth factor in pyridoxine-induced neuropathy dogs. J Vet Sci 9(4):367-373
  7. Dordain G & Deffond D (1994) Pyridoxine neuropathies. Review of the literature. Therapie 49(4):333-337
  8. Araujo JA et al (2008) Improvement of short-term memory performance in aged beagles by a nutraceutical supplement containing phosphatidylserine, Ginkgo biloba, vitamin E, and pyridoxine. Can Vet J 49(4):379-385
  9. Villar D et al (1995) Treatment of acute isoniazid overdose in dogs. Vet Hum Toxicol 37(5):473-477
  10. Vail DM et al (1998) Efficacy of pyridoxine to ameliorate the cutaneous toxicity associated with doxorubicin containing pegylated (Stealth) liposomes: a randomized, double-blind clinical trial using a canine model. Clin Cancer Res 4(6):1567-1571