他達拉非
Tadalafil
別名: Cialis · Adcirca · GF-196960 · IC-351 · tadalafiili · tadalafilo · tadalafilum
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Pulmonary arterial hypertension | 1 mg/kg PO q48h (every other day) | PO | q48h | — | 🌎 NA |
| Pulmonary arterial hypertension | 1 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
- Pulmonary arterial hypertension: Added to background treatment (furosemide, spironolactone, benazepril, dexamethasone, oxygen).
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
概覽
他達拉非 (Tadalafil) 是一種長效的第五型磷酸二酯酶 (PDE5) 抑制劑，在獸醫學中主要用於控制犬隻的肺動脈高壓 (PAH)。
- 臨床重點：與西地那非 (Sildenafil) 相比，他達拉非的半衰期顯著較長，允許每日一次或每兩日一次給藥，大幅提高飼主的順從性。
- 當右心壓力持續升高時，常作為傳統心臟衰竭藥物（如匹莫苯、利尿劑、ACE抑制劑）的輔助療法。
- 注意：目前在獸醫物種中的臨床數據和已發表的文獻非常有限，且藥費可能相當昂貴。
作用機制
Tadalafil selectively inhibits cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5).
Mechanism Pathway: Endothelial stimulation → Nitric Oxide (NO) release → Activation of guanylate cyclase → Increased cGMP production.
Normally, PDE5 (found in pulmonary vascular smooth muscle, corpus cavernosum, and platelets) degrades cGMP. By inhibiting PDE5, tadalafil prevents this degradation.
Increased intracellular cGMP → Decreased intracellular calcium in smooth muscle cells → Relaxation of pulmonary vascular smooth muscle → Vasodilation and significant reduction of pulmonary arterial pressure (PAP).
安全性與警告
禁忌症
- Concurrent use of any form of organic nitrates (regularly or intermittently)
- Serious hypersensitivity to tadalafil
不良反應
- Cutaneous flushing of the inguinal region
- Gastrointestinal upset (dyspepsia, nausea)
- Decreased neutrophils and platelets (observed at 4X-18X human equivalent doses; reversible)
- Hypotension (especially if combined with other vasodilators)
- Myalgia or back pain (reported in humans)
- Headache or nasal congestion (reported in humans)
注意事項
Dosage reductions may be required in patients with severe hepatic or renal impairment. Use with extreme caution in patients on concurrent antihypertensive therapies. The safety profile in dogs is not fully established; monitor closely for adverse effects.
藥物相互作用
May increase hypotensive effects
Potential to increase hypotensive effects
Potentially could increase hypotensive effects
May reduce tadalafil metabolism and increase AUC
May reduce tadalafil metabolism and increase AUC
May reduce tadalafil metabolism and increase AUC
Significant potentiation of vasodilatory effects; life-threatening hypotension possible
Significant potentiation of vasodilatory effects; life-threatening hypotension possible
May decrease tadalafil concentrations
May decrease tadalafil concentrations
監測
- Clinical efficacy (improved syncope, cough, respiratory effort)
- Pulmonary artery pressure (via echocardiography)
- Systemic blood pressure
- Adverse effects (GI upset, flushing)
藥物動力學
半衰期
吸收
Human data: Maximum plasma concentrations occur at around 4 hours. Food does not alter the rate or extent of absorption.
分佈
Human data: 94% bound to plasma proteins.
代謝
Human data: Metabolized by CYP3A4 to a catechol metabolite that undergoes methylation and glucuronidation (inactive metabolites).
排除
Human data: Excretion is primarily via fecal routes (61%) with the remainder in the urine (approximately 36%).
過量
Little information is available for veterinary species. In humans, single doses up to 500 mg and multiple daily doses up to 100 mg produced adverse reactions similar to those seen at lower doses. Overdoses in animals are expected to mirror the drug's adverse effect profile (e.g., severe hypotension, tachycardia, flushing). Treat supportively and contact an animal poison control center for guidance.
可用產品
劑型
- Oral tablets
人用標示
- Tadalafil Oral Tablets: 2.5 mg, 5 mg, 10 mg, 20 mg (Cialis®, Adcirca®)
各地核准狀態
暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store tablets at room temperature between 59°-86°F (15° and 30°C).
飼主須知
這是什麼藥物？ 他達拉非用於治療肺部高血壓（肺動脈高壓），幫助您的狗狗呼吸更順暢、提高運動耐受力並減少暈厥發作。
給藥方式： 可與食物一起或空腹給予。
重要警告：
如果您的寵物正在服用任何硝酸鹽類藥物（如硝酸甘油），請絕對不要給予此藥，因為這可能導致致命的血壓下降。
副作用： 請留意腸胃不適、皮膚發紅（特別是無毛的腹部區域）或嗜睡。若有任何異常跡象，請向您的獸醫師報告。
費用與仿單外使用： 這是用於寵物的「仿單外」人類藥物。由於它是一種較新的長效藥物，可能相當昂貴。如有任何財務考量，請與您的獸醫師討論。
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用，不能取代專業判斷或廠方最新藥品說明書。