リュープロレリン
**リュープロレリン**は、ゴナドトロピン放出ホルモン（GnRH）の合成ノナペプチドアナログです。獣医療では主に、**フェレットの副腎疾患（副腎随伴性内分泌障害）**の内科的治療や、**飼育鳥の不適切な産卵や繁殖障害**の抑制に使用されます。 主な臨床的ポイント： * **フェレットの副腎疾患**：犬とは異なり、フェレットの副腎疾患はコルチゾールではなく、過剰な性ホルモン（アンドロゲン/エストロゲン）によって引き起こされます。リュープロレリンは、これらの臨床症状（脱毛、外陰部の腫脹、掻痒など）の原因となるホルモン軸を効果的に抑制します。 * **剤形**：1、3、または4ヶ月にわたって持続的に放出される長時間作用型の**デポ注射剤**（マイクロスフィア）として投与されるのが最も一般的です。 * **費用**：この薬は非常に高価ですが、調剤薬局がエキゾチックアニマル用にヒト用のバイアルをより安価な小分けにして提供することがよくあります。 * **安全性**：催奇形性が高く、妊娠中の使用は絶対に禁忌です。
作用機序: Leuprolide acts as a **luteinizing hormone-releasing hormone (LHRH/GnRH) agonist**. * **Initial Phase (Flare)**: Upon initial administration, it stimulates the pituitary gland, causing a transient surge in **luteinizing hormone (LH)** and **follicle-stimulating hormone (FSH)**. * **Downregulation Phase**: Continuous exposure via depot formulation causes profound downregulation and desensitization of **GnRH receptors** in the anterior pituitary. * **Suppression**: This negative feedback → halts the release of **LH** and **FSH** → drastically decreases serum levels of gonadal steroids (**estrogen** and **androgens**), thereby resolving hormonally driven clinical signs.
動物種別の用量
- Adrenal associated endocrinopathy (30-day formulation) · 100 micrograms/kg (females) or 200 micrograms/kg (males) · IM · q30d · Lifelong/Ongoing · Proven effective for management of the disease.
- Adrenal associated endocrinopathy (3-month formulation) · 1 mg (total dose) · IM · every 60-75 days · Lifelong/Ongoing · Length of control in intact ferrets in Spring; may be useful for annual Dec/Feb suppression.
- Adrenal associated endocrinopathy (4-month formulation) · 2 mg (total dose) · IM · every 70-80 days · Lifelong/Ongoing · Anecdotal time before signs reappear; may be useful for annual Dec/Feb suppression.
- Adrenal associated endocrinopathy (30-day formulation, weight-based) · <1 kg: 100 micrograms; >1 kg: 200 micrograms · IM · q30d · Lifelong/Ongoing · Generally diluted from original concentration to negate muscle necrosis. Diluted form appears active after freezing for a year (though manufacturer advises against freezing).
- Adrenal associated endocrinopathy (1-month depot form) · 100-250 micrograms/kg · IM · every 4 weeks until signs resolve, then every 4-8 weeks as needed · Lifelong · Larger ferrets may require the higher dosage range.
- Inappropriate egg laying in Cockatiels (if management changes fail) · 800 micrograms/kg IM every 2 weeks for 3 injections · IM · q14d · 3 injections · Often effective at reducing reproduction at least in the short-term.
- Inhibit egg laying in pet birds · 100 micrograms/kg per day. Multiply dose by number of days for effect and give once monthly (e.g., 100 mcg/kg x 28 days = 2800 mcg/kg dose) · IM · q30d · Monthly
投与経路
禁忌
- Pregnancy (FDA Category X - major fetal abnormalities may result)
- Nursing/lactating animals (use with extreme caution, excretion in milk is unknown)
有害事象
- Pain or irritation at the injection site
- Dyspnea (reported in ferrets)
- Lethargy (reported in ferrets)
- Tachyphylaxis (higher dosages required over time to obtain the same effect in ferrets)
- Transient worsening of clinical signs (flare effect) shortly after initial administration
モニタリング
- Ferrets: Resolution of clinical signs (decreased vulvar swelling, reduced pruritus, cessation of undesirable sexual behaviors/aggression, and increased hair regrowth)
- Birds: Decreased egg-laying behavior and physical reproductive activity
- Injection site for signs of pain, irritation, or necrosis
過量投与
Because of its high expense and the method of dosing (usually administered by the veterinarian in-clinic), an acute overdose is highly unlikely. Studies in laboratory animals at massive dosages of up to 5 grams/kg IM produced no untoward effects, suggesting a wide margin of safety for acute exposure.
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。