カベルゴリン
**カベルゴリン**は、主に強力なプロラクチン低下作用を目的として獣医療で使用される合成麦角誘導体です。 * **主な適応症：** 犬および猫の偽妊娠の治療、発情誘起/同期化、妊娠中絶、および乳腺炎の管理。 * **臨床的利点：** ブロモクリプチンなどの古いドパミン作動薬と比較して、カベルゴリンは忍容性がはるかに高く、受容体特異性が高く、作用時間が長く、嘔吐の発生率が著しく低いです。 * **適応外使用：** 犬の下垂体依存性副腎皮質機能亢進症（クッシング症候群）やオウムの持続的産卵の治療において、一定の有効性が示されています。 * **コストの考慮：** 特に大型犬では非常に高価になる可能性がありますが、現在ではジェネリック錠剤が利用可能です。正確な獣医用量を得るために、通常は薬剤師による調剤が必要です。
作用機序: Cabergoline is a highly specific, long-acting **dopamine D2 receptor agonist**. * **Mechanism:** It binds with high affinity to **D2 receptors** on lactotroph cells in the anterior pituitary gland. * **Pathway:** **D2 receptor activation** → inhibition of adenylyl cyclase → decreased intracellular cAMP → direct suppression of **prolactin** synthesis and secretion. * **Reproductive Impact:** Because prolactin is luteotropic in dogs and cats (it maintains the corpus luteum during the second half of pregnancy), suppressing prolactin leads to a drop in progesterone. This mechanism is responsible for its ability to terminate pregnancy, resolve pseudopregnancy, and induce estrus.
動物種別の用量
- Estrus induction · 5 micrograms/kg PO once daily induces fertile proestrus in 4-25 days. · PO · q24h · 4-25 days
- Estrus induction · 5 micrograms/kg PO once daily until an induced proestrus is pronounced for 2 days or until onset of estrus · PO · q24h · Until proestrus is pronounced for 2 days or onset of estrus
- Estrus induction · 0.6 micrograms/kg PO once daily. Make a 10 micrograms per mL solution by dissolving commercial tablets in warm distilled water (One 0.5 mg tablet (500 micrograms) per 50 mL of distilled water.) Give the appropriate dose for the patient within 15 minutes of preparation and discard the remaining solution. Continue until day 2 after the onset of the first signs of proestrus, or until day 42 without signs of proestrus. · PO · q24h · Until day 2 after onset of proestrus, or up to 42 days · 81% (22 of 27) of dogs treated at this low dose showed proestrus between days 4 and 48.
- Pseudocyesis (pseudopregnancy) · 5 micrograms/kg once a day PO for 5-10 days. · PO · q24h · 5-10 days
- Pseudocyesis · 5 micrograms/kg once a day or every other day SC · SC · q24h or q48h · Not specified · Likely needs to be compounded.
- Pseudocyesis · 5 micrograms/kg PO once daily for 4-5 days; occasional failures can be handled by repeating treatment and extending duration to 8-10 days. · PO · q24h · 4-5 days (up to 8-10 days) · Additional protocols for treatment failures include combining cabergoline with metergoline (500 micrograms/kg PO twice daily), or cabergoline with bromocriptine (10-30 micrograms/kg PO twice daily).
- Adjunctive treatment of mastitis after puppies weaned · 5 micrograms/kg PO daily. · PO · q24h · Not specified
投与経路
禁忌
- Pregnancy (unless abortion is desired)
- Hypersensitivity to ergot derivatives
- Uncontrolled hypertension (in humans)
- Nursing mothers
有害事象
- Vomiting (infrequent, alleviated by food)
- Coat color changes (in dogs treated >14 days)
- Postural hypotension (reported in humans)
- Dizziness (reported in humans)
- Headache (reported in humans)
- Nausea (reported in humans)
薬物相互作用
- Hypotensive Drugs · Concomitant use may cause additive hypotension due to cabergoline's hypotensive effects.
- Metoclopramide · Use with cabergoline may reduce the efficacy of both drugs and should be avoided. · major
- Phenothiazines (e.g., acepromazine, chlorpromazine) · Use of cabergoline with dopamine (D2) antagonists may reduce the efficacy of both drugs and should be avoided.
- Domperidone · Antagonizes the therapeutic effect of cabergoline · major
- Phenothiazines (e.g., Acepromazine) · May antagonize cabergoline effects due to dopamine receptor blockade · moderate
- Hypotensive agents · Additive hypotensive effects · moderate
モニタリング
- Clinical efficacy (resolution of pseudopregnancy, estrus induction, etc.)
- Adverse effects (vomiting, behavioral changes)
過量投与
Overdose information is not available for dogs or cats, and remains very limited for humans. * **Potential Signs:** It is postulated that cabergoline overdoses could cause severe hypotension, nasal congestion, syncope, or hallucinations. * **Treatment:** Treatment is basically supportive and primarily focuses on supporting cardiovascular function and blood pressure.
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。