去氧腎上腺素
Phenylephrine
Phenylephrine Hydrochloride
別名: Neo-Synephrine · AH-chew D · Little Colds Decongestant · Lusonal · Nasop · Sudogest PE · Sudafed PE · Pedia Care Children's Decongestant · Triaminic Thin Strips Cold · Minims Phenylephrine · fenilefrina · phenylephrinum · m-synephrine · Phenylephrine hydrochloride
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
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| As a CRI to increase peripheral vascular resistance and mean arterial blood pressure | Low dose is 1 microgram/kg/min; high dose is 3 micrograms/kg/min | IV | CRI | — | 🌎 NA |
| As a constant rate infusion for profound vasodilation due to septic shock | 2-10 micrograms/kg/minute | IV | CRI | — | 🌎 NA |
| As a vasopressor in catastrophic stages of hypovolemic shock | 1-3 micrograms/kg/min | IV | CRI | — | 🌎 NA |
| Diagnosis of Horner's syndrome (denervation hypersensitivity) | 1% or 10% solution topically to both eyes | topical | once | single dose | 🌍 EU |
| Hypotension secondary to drugs or vascular failure | Used in conjunction with fluid therapy (exact dose not specified in monograph) | IV | CRI or as directed | Until blood pressure stabilizes | 🌍 EU |
- As a CRI to increase peripheral vascular resistance and mean arterial blood pressure: May see reflex bradycardia, and vasoconstriction can lead to excessive decreases in blood flow to liver, GI tract, and kidneys, although coronary blood flow is increased.
- Diagnosis of Horner's syndrome (denervation hypersensitivity): Time to dilation indicates lesion location: <20 mins = 3rd-order HS; 20-45 mins = 2nd-order HS; 60-90 mins = 1st-order HS or normal. 10% solution causes mydriasis in 5-8 mins in post-ganglionic lesions.
- Hypotension secondary to drugs or vascular failure: Use with caution; raises BP at the expense of vital organ perfusion.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| To increase blood pressure by vasoconstriction in pronounced systemic vasodilation or when increasing myocardial contractility is disadvantageous (e.g., hypertrophic cardiomyopathy) | 1-2 micrograms/kg/minute | IV | CRI | — | 🌎 NA |
| As a constant rate infusion for profound vasodilation due to septic shock | 2-10 micrograms/kg/minute | IV | CRI | — | 🌎 NA |
| As a vasopressor in catastrophic stages of hypovolemic shock | 1-3 micrograms/kg/min | IV | CRI | — | 🌎 NA |
| As a CRI to increase peripheral vascular resistance and mean arterial blood pressure | Low dose is 1 microgram/kg/min; high dose is 3 micrograms/kg/min | IV | CRI | — | 🌎 NA |
| Diagnosis of Horner's syndrome (denervation hypersensitivity) | 1% solution topically to both eyes | topical | once | single dose | 🌍 EU |
- To increase blood pressure by vasoconstriction in pronounced systemic vasodilation or when increasing myocardial contractility is disadvantageous (e.g., hypertrophic cardiomyopathy): Infusions of 1 microgram/kg/min significantly increased mean arterial pressure without a change in cardiac output. At 2 micrograms/kg/min, cardiac index also was increased with an increase in stroke volume index.
- As a CRI to increase peripheral vascular resistance and mean arterial blood pressure: May see reflex bradycardia, and vasoconstriction can lead to excessive decreases in blood flow to liver, GI tract, and kidneys, although coronary blood flow is increased.
- Diagnosis of Horner's syndrome (denervation hypersensitivity): Use lower concentrate solutions in cats to avoid systemic hypertension.
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| General use | 5 mg | IV | Single dose | — | 🌎 NA |
- General use: ARCI UCGFS Class 3 Drug
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
去氧腎上腺素 (Phenylephrine) 是一種強效、直接作用的合成擬交感神經胺，在獸醫學中主要利用其強大的血管收縮特性。
主要臨床應用包括：
- 低血壓與休克：在充分補充血容量後，以腸胃外途徑給藥來提升血壓，且不會引起明顯的心臟刺激。
- 藥物引起的低血壓：對於因藥物過量或特異性反應（如吩噻嗪類、腎上腺素阻斷劑）引起的低血壓危機非常有效。
- 眼科應用：局部應用於診斷性眼科檢查、減少虹膜後沾黏的形成，以及緩解複雜性葡萄膜炎相關的疼痛。
- 鼻腔去充血：鼻內給藥以減少黏膜充血。
臨床要點：由於去氧腎上腺素在正常劑量下缺乏顯著的 β-腎上腺素活性，當需要升高血壓但禁忌增加心率或心肌耗氧量時（例如肥厚型心肌病患者），此藥物特別有用。
作用機轉
Phenylephrine is a highly selective alpha-1 adrenergic receptor agonist.
- Vascular Smooth Muscle: Binds to post-synaptic alpha-1 receptors → activates Gq-proteins → stimulates Phospholipase C (PLC) → cleaves PIP2 into Inositol Triphosphate (IP3) and Diacylglycerol (DAG) → IP3 triggers the release of intracellular calcium from the sarcoplasmic reticulum → profound vasoconstriction.
- Cardiovascular Effects: Intravenous administration causes peripheral vasoconstriction, leading to significant increases in both diastolic and systolic blood pressures. This sudden increase in blood pressure often triggers a baroreceptor-mediated reflex bradycardia (which can be blocked by anticholinergics like atropine).
- Organ Perfusion: Constricts most vascular beds (renal, splanchnic, pulmonary, cutaneous), though coronary blood flow is typically increased due to elevated aortic diastolic pressure.
安全性與警告
禁忌症
- Severe hypertension
- Ventricular tachycardia
- Hypersensitivity to phenylephrine
- Do not apply topically once ophthalmic surgery has started (to avoid direct arterial absorption)
不良反應
- Reflex bradycardia
- CNS effects (excitement, restlessness, headache)
- Arrhythmias (rare)
- Severe extravasation injuries (tissue necrosis and sloughing)
- Hypertension
- Tachycardia
- Tissue necrosis and sloughing (if IV extravasation occurs)
注意事項
WARNING: Extravasation injuries with phenylephrine can be very serious, leading to necrosis and sloughing of surrounding tissue. IV sites must be routinely monitored. If extravasation occurs, infiltrate the ischemic area with 5-10 mg phentolamine in 10-15 mL of normal saline using a fine needle.
- Extreme Caution: Use carefully in geriatric patients, and those with hyperthyroidism, bradycardia, partial heart block, or other heart disease.
- Not a Substitute for Fluids: Phenylephrine is not a replacement for adequate volume therapy in patients with shock; hypovolemia must be corrected first.
- Pregnancy: FDA Category C. Can cause contraction of the pregnant uterus and constriction of uterine blood vessels. Use with caution.
藥物交互作用
Higher dosages of phenylephrine may be required to attain a pressor effect if these agents have been used prior to therapy.
Potentially may induce cardiac arrhythmias when used with halothane anesthesia.
Block the reflex bradycardia caused by phenylephrine.
The cardiostimulatory effects of phenylephrine (seen at high doses) can be blocked.
Use with phenylephrine may cause increased myocardium sensitization.
Should not be used with phenylephrine because of a pronounced pressor effect.
When used concurrently with oxytocic agents, pressor effects may be enhanced.
Tachycardia and serious arrhythmias are possible.
Increased risk of cardiac arrhythmias
Enhanced pressor effects leading to severe hypertension
監測
- Cardiac rate and rhythm
- Blood gases (if possible)
- IV catheter site (for signs of extravasation)
- Blood pressure (systemic use or high-concentration topical use)
- Heart rate and rhythm (ECG)
- Pupillary response and time to dilation (for Horner's syndrome testing)
藥物動力學
半衰期
吸收
After oral administration, phenylephrine is rapidly metabolized in the GI tract and cardiovascular effects are generally unattainable via this route. Following IV administration, pressor effects begin almost immediately and persist for up to 20 minutes. IM onset is 10-15 minutes, lasting approximately one hour.
分佈
It is unknown if phenylephrine is excreted into milk.
代謝
Metabolized by the liver.
排除
The effects of the drug are terminated by uptake into tissues.
過量
The margin of safety with phenylephrine overdose is fairly wide, especially after oral administration.
Clinical Signs:
- Common findings in dogs include vomiting, lethargy, depression, hyperactivity, and tachycardia.
- Severe overdosage can cause hypertension, seizures, paresthesias, ventricular extrasystoles, and cerebral hemorrhage.
Treatment:
- Vomiting is commonly seen and may self-decontaminate oral exposures.
- Cardiovascular changes often respond well to IV fluids.
- Beta-blockers or nitroprusside may be indicated when signs (tachycardia, severe hypertension) are refractory to fluids.
可用產品
劑型
- Injection
- Oral tablets
- Oral solution/liquid
- Oral strips
- Ophthalmic drops
- Intranasal sprays
- Injectable: 1% (10 mg/ml) solution
- Ophthalmic: 2.5% solution (single-dose vials)
- Ophthalmic: 10% solution (single-dose vials)
獸醫用
- Oral combination products marketed as 'cough' syrups containing phenylephrine, pyrilamine, guaifenesin, sodium citrate, and sometimes ammonium chloride.
- Phenylephrine 1% injectable solution
- Phenylephrine 2.5% ophthalmic solution
- Phenylephrine 10% ophthalmic solution
人用標示
- Phenylephrine HCl Oral Tablets: 10 mg (regular & chewable)
- Phenylephrine HCl Oral Solution/Liquid: 2.5 mg/mL (concentrate), 2.5 mg/5mL & 7.5 mg/5 mL
- Phenylephrine HCl Oral Strips: 2.5 mg
- Phenylephrine HCl Injection: 1% (10 mg/mL) in 1 mL & 5 mL vials and 1 mL Uni-Nest amps
- Ophthalmic and intranasal dosage forms
- Minims Phenylephrine Hydrochloride 2.5% and 10% eye drops
各地核准狀態
POM (Prescription Only Medicine)
POM-V or POM depending on specific formulation.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
The injectable product should be stored protected from light. Do not use solutions if they are brown or contain a precipitate. Oxidation of the drug can occur without a color change. Commercially available ampules have air replaced with nitrogen and a sulfite added to protect against oxidation.
飼主須知
- 醫院使用：注射用去氧腎上腺素是一種強效的心血管藥物，只能由獸醫專業人員在具備連續血壓和心電圖監測條件的臨床環境中使用。
- 口服產品：含有去氧腎上腺素的人用非處方感冒藥，在未經獸醫明確指示下，絕對不可給寵物服用。這些藥物通常含有其他有毒成分（如普拿疼或去充血劑），可能導致嘔吐、過度活躍或心率異常。
- 意外誤食：如果您的寵物意外誤食含有去氧腎上腺素的產品，請立即聯繫您的獸醫或動物毒物控制中心。
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