催產素
Oxytocin
alpha-hypophamine
別名: Pitocin · Syntocinon · alpha-hypophamine · oxytocinum
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
0.5-3 Units SC or IM every 30-60 minutes, best based upon the results of tokodynamometry.SC/IM· q30-60m· Until parturition is complete
0.5–3 unit — 每隻動物的固定劑量（不按體重換算）
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 |
|---|---|---|---|---|---|
| To augment uterine contractions during parturition | 0.5-3 Units SC or IM every 30-60 minutes, best based upon the results of tokodynamometry. | SC/IM | q30-60m | Until parturition is complete | 🌎 NA |
| For uterine inertia (if no fetuses in birth canal, cervix dilated, obstruction ruled out) | 5-20 Units (depending on size of animal) IM or as an IV drip (10 Units/liter) beginning as a slow drip and gradually increasing until effective contractions are observed. If no response to IM injection in 30 minutes, may repeat along with 10% dextrose IV slowly. If no response again in 30 minutes, repeat IM again. | IM/IV | As directed | — | 🌎 NA |
| For uterine inertia (mini-dose protocol) | 0.25 Units (total dose) SC or IM to a maximum dose of 4 Units per bitch. Generally not given more frequently than hourly. | SC/IM | q1h | — | 🌎 NA |
| To induce milk let-down (adequate milk production, tolerates nursing) | Oxytocin nasal spray: 5-10 minutes prior to nursing three times daily | Intranasal | TID | — | 🌎 NA |
| For secondary agalactia | 0.25-1 Unit (total dose) SC q2h. | SC | q2h | — | 🌎 NA |
| For adjunctive treatment of acute metritis | 0.5-5 Units (total dose) IM | IM | Once | — | 🌎 NA |
| To promote uterine involution after uterine prolapse manual reduction | 0.5-5 Units IM (Traas & O'Conner 2009) OR 5-10 Units (total dose) IM (Shaw 2007) | IM | Once | — | 🌎 NA |
- For uterine inertia (if no fetuses in birth canal, cervix dilated, obstruction ruled out): Some texts recommend giving calcium gluconate (2-10 mL slowly IV) prior. If no response, perform C-section.
- For uterine inertia (mini-dose protocol): Given 15 minutes after calcium gluconate 10% (1 mL/5.5 kg SC). Higher doses can cause tetanic contractions.
- For secondary agalactia: Remove neonates for 30 mins post-injection. Often used with metoclopramide 0.1-0.2 mg/kg SC q12h.
- For adjunctive treatment of acute metritis: May be used if birth occurred less than 24 hours prior.
- To promote uterine involution after uterine prolapse manual reduction: Given following successful manual reduction.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| To promote uterine involution after uterine prolapse manual reduction | 0.5-5 Units IM OR 5-10 Units (total dose) IM | IM | Once | — | 🌎 NA |
| To treat primary uterine inertia | 0.25 Units (total dose) SC or IM to a maximum dose of 4 Units per queen. Generally not given more frequently than hourly. | SC/IM | q1h | — | 🌎 NA |
| For adjunctive treatment of metritis | 0.5-5 Units IM | IM | Once | — | 🌎 NA |
| To induce milk let-down (secondary agalactia) | 0.25-1 Unit (total dose) SC q2h. | SC | q2h | — | 🌎 NA |
- To promote uterine involution after uterine prolapse manual reduction: Extrapolated from dog doses.
- To treat primary uterine inertia: Given 15 minutes after calcium gluconate.
- For adjunctive treatment of metritis: May be used if birth occurred less than 24 hours prior.
- To induce milk let-down (secondary agalactia): Remove neonates for 30 mins post-injection. Often used with metoclopramide.
小型哺乳類
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Uterotonic / Obstetrical use (Mice, Rats, Gerbils, Hamsters, Guinea pigs, Chinchillas) | 0.2-3 Units/kg IV, IM or SC | IV/IM/SC | Once | — | 🌎 NA |
鳥
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| As a uterotonic agent | 0.5 Units/kg IM; may repeat in 60 minutes | IM | May repeat in 60m | — | 🌎 NA |
| For egg expulsion | 0.01-0.1 mL once IM. | IM | Once | — | 🌎 NA |
- For egg expulsion: Should be administered with Vitamin A and calcium (injectable).
爬蟲類
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For egg binding | 1-10 Units/kg IM. | IM | As needed | — | 🌎 NA |
| To induce oviposition | 1-30 Units/kg (10 Units/kg appears effective in many chelonians). May have to repeat in several hours. | IM | May repeat in several hours | — | 🌎 NA |
- For egg binding: Given in combination with calcium glubionate. Use care with multiple injections. Not as effective in lizards.
- To induce oviposition: Risk of oviduct rupture if cloaca is obstructed.
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| To augment or initiate uterine contractions during parturition in properly evaluated mares | 2.5-5 Units IV, every 15-20 minutes until foal is born | IV | q15-20m | Until foal is born | 🌎 NA |
| To prevent luteolysis (prolong corpus luteum lifespan) | 60 Units (3 ml) IM once daily from day 7 to day 14 post-ovulation. | IM | q24h | Days 7 to 14 post-ovulation | 🌎 NA |
| For evacuation of uterine fluid | 20 Units IV or IM one to three times a day | IV/IM | SID to TID | — | 🌎 NA |
| To aid in removal of retained fetal membranes | 30-100 Units in 1 liter of normal saline IV over 30-60 minutes OR 10-120 Units IM OR 10-40 Units by IV bolus | IV/IM | Once | — | 🌎 NA |
| To aid in removal of retained fetal membranes (alternative) | 20 Units IV or IM given every hour beginning 2-3 hours after foaling. Repeat as needed. | IV/IM | q1h | As needed | 🌎 NA |
| For mild to moderate cases of acute post-partum metritis | 20 Units IM 3-4 times a day for 2-3 days | IM | TID to QID | 2-3 days | 🌎 NA |
| To treat esophageal obstruction ('choke') | 0.11-0.22 Units/kg IV once | IV | Once | — | 🌎 NA |
- To prevent luteolysis (prolong corpus luteum lifespan): Ovulation must be documented closely.
- To aid in removal of retained fetal membranes: Large dose IV boluses are not recommended as they may cause uterine spasm and abdominal discomfort.
- To treat esophageal obstruction ('choke'): Given with N-butylscopolammonium bromide. Avoid or reduce dose in mares. Do not use in pregnant mares.
牛
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For retained placenta | 40-60 Units oxytocin q2h as necessary. | IM/IV | q2h | As necessary | 🌎 NA |
| To reduce incidence of retained placenta | 20 Units IM immediately following calving and repeated 2-4 hours later | IM | Once, then repeat in 2-4h | — | 🌎 NA |
| For mild to moderate cases of acute post-partum metritis | 20 Units IM 3-4 times a day for 2-3 days | IM | TID to QID | 2-3 days | 🌎 NA |
| To augment uterine contractions during parturition | 30 Units IM; repeat no sooner than 30 minutes if necessary | IM | q30m | As necessary | 🌎 NA |
| For obstetrical use in cows | 100 Units IV, IM or SC | IV/IM/SC | Once | — | 🌎 NA |
| For milk let-down in cows | 10-20 Units IV | IV | Once | — | 🌎 NA |
- For retained placenta: Often used with IV calcium. Limited value after 48 hours postpartum.
豬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For adjunctive treatment of agalactia syndrome (MMA) in sows | 30-40 Units per sow at 3-4 hours | IM/IV | q3-4h | — | 🌎 NA |
| For adjunctive treatment of agalactia syndrome (MMA) in sows (alternative) | 20-50 Units IM or 5-10 Units IV | IM/IV | Once | — | 🌎 NA |
| For retained placenta in patients with uterine atony | 20-30 Units oxytocin q2-3h as necessary | IM/IV | q2-3h | As necessary | 🌎 NA |
| To augment uterine contractions during parturition | 10 Units IM; repeat no sooner than 30 minutes if necessary | IM | q30m | As necessary | 🌎 NA |
| For obstetrical use in sows | 30-50 Units IV, IM or SC | IV/IM/SC | Once | — | 🌎 NA |
| For mild to moderate cases of acute post-partum metritis | 5-10 Units IM 3-4 times a day for 2-3 days | IM | TID to QID | 2-3 days | 🌎 NA |
| For mild to moderate cases of acute post-partum metritis (alternative) | 5 Units IM; may need to be repeated as effect may be as short as 30 minutes | IM | As needed | — | 🌎 NA |
| For milk let-down in sows | 5-20 Units IV | IV | Once | — | 🌎 NA |
- For retained placenta in patients with uterine atony: Use with broad-spectrum antibiotics.
羊
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For retained placenta in patients with uterine atony | 10-20 Units oxytocin. | IM/IV | Once | — | 🌎 NA |
| For mild to moderate cases of acute post-partum metritis | 5-10 Units IM 3-4 times a day for 2-3 days | IM | TID to QID | 2-3 days | 🌎 NA |
- For retained placenta in patients with uterine atony: Limited value after 48 hours postpartum. Note for CAMELIDS (NW): 5-10 Units IM at 10-minute intervals for retained placenta (Adams 2008).
山羊
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For retained placenta in patients with uterine atony | 10-20 Units oxytocin. | IM/IV | Once | — | 🌎 NA |
| For mild to moderate cases of acute post-partum metritis | 5-10 Units IM 3-4 times a day for 2-3 days | IM | TID to QID | 2-3 days | 🌎 NA |
| To control post-extraction cervical and uterine bleeding after internal manipulations | 10-20 Units IV, may repeat SC in 2 hours | IV/SC | Once, may repeat in 2h | — | 🌎 NA |
- For retained placenta in patients with uterine atony: Limited value after 48 hours postpartum.
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
催產素是一種由下丘腦室旁核和視上核合成，並儲存於垂體後葉的九肽激素。在獸醫學中，它主要作為子宮收縮劑，用於引產或增強分娩時的子宮收縮、治療產後胎盤滯留和子宮內膜炎、促進子宮復舊，以及在無乳症情況下促進排乳。
臨床要點：
- 偏好微量給藥 (Mini-dosing)： 現代獸醫產科學強烈建議使用「微量劑量」（例如狗的總劑量為 0.25-4 單位），而非傳統的高劑量。高劑量會導致強直性、無效的子宮收縮，透過壓迫胎盤損害胎兒氧氣供應，並增加子宮破裂的風險。
- 鈣依賴性： 催產素的功效高度依賴細胞外鈣離子。給藥前必須糾正低血鈣或低血糖。鈣能增加收縮的「強度」，而催產素增加的是「頻率」。
- 子宮頸狀態： 如果子宮頸未開或存在未經矯正的阻塞性難產，絕對不可使用催產素。
作用機制
Oxytocin exerts its effects by binding to specific G-protein coupled oxytocin receptors (OXTR) on the cell membrane of uterine myofibrils and myoepithelial cells of the mammary gland.
- Uterine Contraction: Binding to OXTR activates the Gq/11 pathway → stimulates Phospholipase C (PLC) → increases inositol triphosphate (IP3) and diacylglycerol (DAG) → triggers the release of intracellular calcium from the sarcoplasmic reticulum. Calcium binds to calmodulin, activating Myosin Light Chain Kinase (MLCK), leading to smooth muscle contraction. The threshold for oxytocin-induced contraction is significantly lowered late in pregnancy due to upregulation of oxytocin receptors by high estrogen levels.
- Milk Let-down: Oxytocin stimulates the contraction of myoepithelial cells surrounding the mammary alveoli, forcing milk into the larger ducts and cisterns. It does not have galactopoietic (milk-producing) properties.
安全性與警告
禁忌症
- Dystocia due to abnormal fetal presentation (unless corrected)
- Closed or unrelaxed cervix
- Known hypersensitivity to oxytocin
- Significant cephalopelvic disproportion
- Obstetrical emergencies where surgical intervention (C-section) is warranted
- Pregnancy (for nasally administered oxytocin)
不良反應
- Uterine cramping and discomfort
- Tetanic uterine contractions (at high doses)
- Uterine rupture
- Fetal compromise or death (due to placental compression)
- Water intoxication (with prolonged high-dose infusions)
- Hypersensitivity reactions (more common with non-synthetic products)
注意事項
Critical Warning: Always evaluate the patient for obstructive dystocia and ensure the cervix is dilated before administration.
- Metabolic Status: Treat hypoglycemia or hypocalcemia before using oxytocin, as uterine fatigue is often secondary to these metabolic deficits.
- Water Intoxication: While oxytocin has minimal antidiuretic properties, water intoxication can occur if administered at too rapid a rate or if excessively large volumes of electrolyte-free IV fluids are given concurrently. Signs include depression, coma, and seizures.
- Fetal Monitoring: Monitor fetal heart rates if possible, as excessive uterine contractions can cause fetal hypoxia.
藥物相互作用
Thiopental
May delay thiopental anesthesia (reported in humans; clinical significance in animals is not firmly established).
Vasoconstrictors (Sympathomimetics)
Concurrent use post-partum may result in severe hypertension. Monitor closely.
監測
- Uterine contractions (frequency, duration, and strength via tokodynamometry if available)
- Status of the cervix (must be dilated)
- Fetal monitoring (heart rate/distress)
- Maternal calcium and glucose levels
藥物動力學
吸收
Destroyed in the GI tract; must be administered parenterally. Intranasal absorption can be erratic. Uterine response is almost immediate after IV administration, and within 3-5 minutes following IM administration.
分佈
Distributed throughout the extracellular fluid. Small quantities cross the placenta and enter the fetal circulation.
代謝
Metabolized rapidly in the liver and kidneys. A circulating enzyme, oxytocinase, can also destroy the hormone.
排除
Very small amounts are excreted unchanged in the urine. Duration of effect in dogs is ~13 minutes (IV) and ~20 minutes (IM/SC).
過量
Effects of overdosage on the uterus depend on the stage of the uterus and the position of the fetus(es).
- Uterine Effects: Hypertonic or tetanic contractions can occur, leading to tumultuous labor, uterine rupture, fetal injury, or fetal death due to compromised placental blood flow.
- Water Intoxication: Can occur if large doses are infused for a long period, especially with large volumes of electrolyte-free IV fluids.
- Early signs: Listlessness, depression.
- Severe signs: Coma, seizures, death.
- Treatment: Stop oxytocin therapy, restrict water access. Severe cases may require osmotic diuretics (mannitol, urea, dextrose) with or without furosemide.
可用產品
劑型
- Injection (solution)
- Nasal spray
獸醫用
- Oxytocin for Injection: 20 USP Units/mL in 10 mL, 30 mL, and 100 mL vials
人用標示
- Oxytocin Solution for Injection: 10 Units/mL in 1 mL amps, 3 mL & 10 mL vials and 10 mL multiple-dose vials (Pitocin®)
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 at temperatures less than 25°C (77°F); do not freeze. Some manufacturers recommend refrigeration (2-8°C), but some products are stable for up to 5 years if stored at less than 26°C.
飼主須知
催產素是一種強效荷爾蒙，用於幫助您的寵物分娩或促進排乳。
- 需要專業監測： 僅應在能夠充分監測其作用的獸醫師直接指導或給藥下使用。
- 誤用風險： 在胎兒卡住或產道未完全打開時給予催產素，可能會導致嚴重的併發症，包括子宮破裂和未出生胎兒的死亡。
- 鼻腔噴霧劑： 如果為您開立了用於促進排乳的鼻腔噴霧劑，請完全按照指示給藥，通常在哺乳前 5-10 分鐘使用。
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