ヒアルロン酸ナトリウム
ヒアルロン酸ナトリウム（一般にヒアルロン酸またはHAと呼ばれる）は、結合組織、滑液、へその緒、および眼の硝子体に豊富に存在する天然の高粘度ムコ多糖類です。獣医学では、主に重度の変形性関節症や全層軟骨欠損を伴わない滑膜炎および骨関節炎の管理に使用されます。 **重要な臨床ポイント：** * **分子量（MW）の違い：** 市販製品の分子量は大きく異なります。滑膜癒着やパンヌス形成を避ける必要がある場合（例：術後の骨片除去など）、滑膜線維芽細胞の増殖を抑制するため、高分子量製品（>1x10^6）が好まれることがよくあります。低分子量製品は一般的に安価であり、関節疾患の症状を効果的に改善することもできます。 * **由来：** 多くの商業用獣医HA製品は鶏冠（トサカ）から抽出されますが、バイオ発酵由来のものもあります。 * **投与方法：** 主に関節内（IA）または静脈内（IV）注射によって投与されますが、経口ゲル製剤も馬の術後関節液貯留を減少させる効果が示されています。
作用機序: Hyaluronate sodium provides both mechanical and pharmacological benefits to the diseased joint: * **Mechanical Support:** Restores the viscoelastic properties of synovial fluid, providing a cushioning effect and boundary lubrication for articular cartilage. * **Anti-inflammatory Pathway:** * **Free Radicals** → Scavenged directly by HA molecules, reducing oxidative damage within the joint capsule. * **Prostaglandins** → Synthesis and release are suppressed, mitigating local inflammation and pain. * **Cellular Modulation:** Reduces the influx of inflammatory proteins and leukocytes into the joint space. Interacts with **CD44 receptors** on synoviocytes and macrophages to downregulate pro-inflammatory cytokines.
動物種別の用量
- Keratoconjunctivitis sicca (dry eye) or corneal ulceration · 1-2 drops per eye · Topical · q4h to q12h (or as needed) · As needed · Frequency depends on the severity of the condition and the viscosity of the product.
- Ocular lubrication / corneal ulceration · 1 drop per eye · Topical · q4h to q12h · As needed · Frequency depends on the severity of the condition.
- Osteoarthritis / Synovitis (Hylartin-V, Hyvisc, Hyalovet) · 20 mg · IA · As directed · Check individual product label for specific dosing.
- Osteoarthritis / Synovitis (Equron) · 10 mg · IA · As directed · Check individual product label for specific dosing.
- Osteoarthritis / Synovitis (Synacid) · 50 mg · IA · As directed · Check individual product label for specific dosing.
- Osteoarthritis / Synovitis (Legend) · 40 mg IV or 20 mg IA · IV/IA · As directed · Check individual product label for specific dosing.
- Reduce joint effusion post-arthroscopic surgery for osteochondritis dissecans (OCD) · 100 mg · PO · once daily · 30 days · Administered as an oral gel (Conquer)
- Ocular lubrication / corneal trauma · 1 drop per eye · Topical · q6h to q12h · As needed · Use with care to avoid stressing the bird during frequent handling.
投与経路
禁忌
- Injection through skin that has been recently fired or blistered
- Injection through skin with excessive scurf or counterirritants
- Use as a substitute for adequate diagnosis (e.g., failing to rule out fractures via radiography)
- Hypersensitivity to hyaluronate or any component of the formulation
有害事象
- Local joint flare (heat, swelling, and/or effusion) post-injection
- Increased incidence of flares when combined with other intra-articular drugs
- Mild transient ocular irritation (rare)
- Temporary blurred vision immediately after application (especially with higher viscosity gels)
モニタリング
- Resolution of clinical signs (lameness, joint effusion)
- Injection site for signs of local reaction (heat, swelling, pain) within 24-96 hours post-injection
- Resolution of clinical signs (e.g., blepharospasm, conjunctival hyperemia)
- Corneal ulcer healing via fluorescein staining
- Schirmer tear test (STT) for dry eye management
過量投与
Acute toxicology studies performed in horses have demonstrated no systemic toxicity associated with overdoses.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。