ゴナドレリン
ゴナドレリンは合成**視床下部ホルモン**（GnRHアナログ）であり、獣医学において主に乳牛の卵胞嚢腫などの繁殖障害の治療に使用されます。 主な特徴： - **作用時間が非常に短い**（数分）。 - 小動物では、診断目的（去勢済かどうかの鑑別、潜在精巣の特定など）や発情・排卵誘起のために適応外使用されます。 - 産業動物に使用した場合、**休薬期間（搾乳・と畜）は不要**です。 - 非常に安全性が高く、副作用の報告はほとんどありません。
作用機序: Gonadorelin acts as a synthetic **GnRH** (Gonadotropin-Releasing Hormone) → binds to receptors on the anterior pituitary gland → stimulates a surge-like release of **FSH** (Follicle Stimulating Hormone) and **LH** (Luteinizing Hormone). - In females (cows, ewes, cats), this LH surge can induce ovulation or luteinization of cystic follicles. - In males, it stimulates testosterone release, which is useful for diagnostic stimulation testing. - Note: A constant infusion initially stimulates LH/FSH release, but eventually causes receptor downregulation and levels return to baseline.
動物種別の用量
- To induce ovulation outside of the breeding season · 100 micrograms injected daily · Injection · q24h · 4-5 days
- To induce ovulation outside of the breeding season in the doe · 100 micrograms injected daily · Injection · q24h · 4-5 days
- To stimulate ovulation after mating · 25 micrograms IM after mating · IM · Once
- For infertility, reduced libido, testis descent in male cats · 1 microgram/kg every 2-3 days · IM · q48-72h
- To detect ovarian remnants in queens after ovariohysterectomy · 25 micrograms per cat · IM · Once · Progesterone level (>1 ng/mL) 1-2 weeks post treatment verifies presence of ovarian tissue.
- To induce ovulation · 20 micrograms IM · IM · Once · Repeat in one week as necessary · Most effective 14 days after onset of estrus.
- To treat ovarian cysts in cattle · 100 micrograms IM or IV · IM/IV · Once
- To treat ovarian cysts in cattle · 100 micrograms IM per cow · IM · Once
- GnRH stimulation test to differentiate castration from cryptorchidism · 50 micrograms IM (Take pre-sample, give injection, 2-3 hours later take post-injection sample) · IM · Once · Castrated dogs have testosterone concentrations <0.1 ng/mL and GnRH does not stimulate.
- GnRH stimulation test to determine if dog has retained testicle · 2.5 micrograms/kg IM (if very small dog use 25 micrograms total dose instead) · IM · Once · Take pre-sample, give injection, take second sample in 60-90 minutes.
- To aid in the descent of cryptorchid testes · 50-100 micrograms SC or IV · SC/IV · Once · Repeat in 4-6 days if no response
- To increase libido in male dogs · 50-100 micrograms IM weekly · IM · Weekly · 4 to 6 weeks · Anecdotal use.
- For cystic ovarian disease in bitches · 3.3 micrograms/kg IM once daily · IM · q24h · 3 days · Elevated progesterone (>2 ng/mL) 1-2 weeks post treatment verifies success.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- None noted on the label
有害事象
- None reported
- Hypersensitivity reactions are highly unlikely with synthetic preparations
モニタリング
- Clinical efficacy (e.g., resolution of cystic ovaries, induction of estrus)
- Serum progesterone levels (for ovarian remnant or cystic ovary verification)
- Serum testosterone levels (for cryptorchidism/castration testing)
過量投与
In doses of up to 120 micrograms/kg, no untoward effects were noted in several species of test animals. Gonadorelin is unlikely to cause significant adverse effects after inadvertent overdosage.
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。