ペルゴリド
ペルゴリドは麦角由来のドパミン作動薬であり、獣医療においては主に馬の**下垂体中葉機能不全（PPID、通称：馬クッシング症候群）**の**標準治療薬**として使用されます。 * **臨床的重要性**：多毛症（換毛遅延/長い被毛）、無気力、筋肉の萎縮、蹄葉炎など、馬のPPIDの臨床症状を管理するための最も効果的な内科的治療法です。 * **入手方法**：ヒト用製剤は心臓弁膜症のリスクにより2007年に米国市場から撤退しているため、現在は動物用調剤薬局（compounding pharmacies）を通じてのみ入手可能です。 * **忍容性**：馬における忍容性は一般的に非常に良好ですが、治療開始時に一過性の食欲不振が見られることがあります。
作用機序: Pergolide acts as a potent, long-acting agonist at **D1 and D2 dopamine receptors** (estimated to be 10-1000 times more potent than bromocriptine). * **Mechanism in PPID:** In healthy horses, the hypothalamus releases dopamine, which tonically inhibits the pituitary pars intermedia. In horses with PPID, there is a neurodegenerative loss of these dopaminergic neurons. * **Pathway:** Pergolide replaces this lost dopamine tone → binds to **D2 receptors** on melanotropes in the pars intermedia → inhibits the hypersecretion of **pro-opiomelanocortin (POMC)** peptides (including ACTH, α-MSH, and CLIP). * This reduction in POMC peptides normalizes endocrine function and alleviates the clinical signs associated with PPID.
動物種別の用量
- Equine 'Cushing's-like' Disease [pituitary pars intermedia dysfunction (PPID)] · Initial dose of 1 mg (total dose) per day for horses and ponies with PPID. If the horse owner is willing to administer half the dose twice daily, this may be preferable on the basis of recent pharmacokinetic data. If anorexia or temporary dullness develop, treatment should be halted for 2 days or until appetite improves, and then restarted at 0.25 mg per day for 2 days, 0.5 mg per day for 2 days, and 0.75 mg per day for 2 days. · PO · q24h or divided q12h
- Equine 'Cushing's-like' Disease [pituitary pars intermedia dysfunction (PPID)] · 1.7-5.5 micrograms/kg · PO · Varies · Dose varies considerably. The higher doses are used in the more advanced cases or those refractory to treatment at a lower dose.
- Equine 'Cushing's-like' Disease [pituitary pars intermedia dysfunction (PPID)] · 0.002 mg/kg. If no improvement is noted within 8-12 weeks, the daily dose can be increased by 0.002 mg/kg monthly up to a total dose of 0.006 mg/kg (3 mg/day for a 500 kg horse). If only a limited response is observed with 0.006 mg/kg dose, addition of cyproheptadine (0.5 mg/kg PO q12h) to pergolide therapy is recommended. · PO · q24h · Usually, only transient anorexia is recognized during the initial week of treatment and can be overcome in time or by cutting the dose in half for 2-4 days.
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
- Hypersensitivity to pergolide or other ergot derivatives
有害事象
- Anorexia/decreased appetite (up to 10% of horses during the first week)
- Colic (rare)
- Diarrhea (rare)
- Lethargy (dogs)
- Vomiting (dogs)
- Hypertension (dogs)
- Ptosis (dogs)
薬物相互作用
- Dopamine antagonists (e.g., phenothiazines) · May decrease the effects of pergolide
- Metoclopramide · May decrease the effects of pergolide
モニタリング
- Dexamethasone suppression test (baseline and at 4-8 weeks post pergolide therapy initiation, repeat in 4-8 weeks if dosage is adjusted)
- Blood glucose (baseline, and if abnormal repeat as per dexamethasone suppression test)
- Clinical signs (hair coat, weight, PU/PD, etc.)
- Periodic CBC and clinical chemistry panel
過量投与
Limited information is available on pergolide overdoses. * **Potential effects:** GI disturbances, CNS effects, seizures, and hypotension. * **Dogs:** Accidental ingestion has resulted in vomiting, lethargy, hypertension, and ptosis. * **Treatment:** Care is primarily supportive. Phenothiazines (dopamine antagonists) may be used to decrease CNS stimulation effects.
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。