オキシモルフォン

Oxymorphone

Oxymorphone HCl

オピオイド作動薬IVIMSCEpiduralRectalPO犬猫小型哺乳類フェレット馬豚

別名: Numorphan · Opana · 7,8-Dihydro-14hydroxymorphinone hydrochloride · oximorphone hydrochloride

VetSheet 獣医チームが監修更新日 2026年4月5日エビデンスに基づく獣医学リファレンス

Up to 0.2 mg/kg IM or IV ; initially a maximum of 5 mg total doseIM/IV· Once

体重— 🐕

用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。

動物種別用量

🌎 NA — North America🌍 EU — Europe

犬

適応	用量	経路	頻度	期間	地域
For sedation for minor procedures	Up to 0.2 mg/kg IM or IV ; initially a maximum of 5 mg total dose	IM/IV	Once	—	🌎 NA
For sedation for minor procedures	0.05-0.1 mg/kg IV or 0.1-0.2 mg/kg IM, SC	IV/IM/SC	Once	—	🌎 NA
For analgesia (acute pain)	0.1-0.2 mg/kg IM, IV, or SC	IM/IV/SC	q1-3h	—	🌎 NA
For analgesia (acute pain) in animals with cardiovascular disease	0.05-0.1 mg/kg IV, IM or SC	IV/IM/SC	q2-4h	—	🌎 NA
Epidural administration	0.05 mg/kg	Epidural	Once	—	🌎 NA
For acute pain	0.1-0.2 mg/kg IM or SC	IM/SC	q3-4h	—	🌎 NA
For analgesia	0.05-0.4 mg/kg IV, IM, or SC	IV/IM/SC	q2-4h	—	🌎 NA
For premedication to anesthesia in healthy dogs	0.05-0.1 mg/kg IM, IV ; 0.2 mg/kg for extra heavy sedation	IM/IV	Once	—	🌎 NA

For sedation for minor procedures: Combine with acepromazine 0.05-0.1 mg/kg IM or IV
Epidural administration: Recommend to dilute with sterile saline to a volume not to exceed 0.3 mL/kg to a maximum of 6 mL. Use of preservative-free opioids is best.
For premedication to anesthesia in healthy dogs: Maximum initial dose: 5 mg.

猫

適応	用量	経路	頻度	期間	地域
As a preanesthetic/analgesic	0.05-0.1 mg/kg IM	IM	Once	—	🌎 NA
As an analgesic (acute pain)	0.05-0.1 mg/kg IM, SC or IV	IM/SC/IV	q1-3h	—	🌎 NA
As an analgesic (acute pain) for animals with cardiovascular disease	0.05-0.1 mg/kg IV, IM or SC	IV/IM/SC	q2-4h	—	🌎 NA
As an analgesic (acute pain)	0.025-0.1 mg/kg IV (IM or SC)	IV/IM/SC	q2-6h	—	🌎 NA
As an analgesic (acute pain)	0.02-0.1 mg/kg IV, IM, or SC	IV/IM/SC	q3-4h	—	🌎 NA

As a preanesthetic/analgesic: may cause dysphoria or excitement, add sedative.
As an analgesic (acute pain): concomitant tranquilization recommended

小型哺乳類

適応	用量	経路	頻度	期間	地域
Analgesia	0.2 mg/kg IM	IM	q2-4h	—	🌎 NA
Anesthetic/analgesic for minor surgical procedures	0.15 mg/kg IM	IM	Once	—	🌎 NA
Analgesia	0.2-0.5 mg/kg SC, IM	SC/IM	q6-12h	—	🌎 NA
Analgesia	0.05-0.2 mg/kg SQ (or IM for rabbits only)	SQ/IM	q8-12 hrs	—	🌎 NA

Analgesia: Rabbits
Anesthetic/analgesic for minor surgical procedures: for a hamster-sized animal
Analgesia: Hamsters, Gerbils, Mice, Rats, Guinea pigs
Analgesia: Rabbits, Rats, Mice, Gerbils, Guinea Pigs, Hamsters, Chinchillas

フェレット

適応	用量	経路	頻度	期間	地域
Analgesia	0.05-0.2 mg/kg IV or IM	IV/IM	2-4 times daily	—	🌎 NA
Analgesia	0.05-0.2 mg/kg SQ or IM	SQ/IM	q8-12 hrs	—	🌎 NA

馬

適応	用量	経路	頻度	期間	地域
As an analgesic	0.01-0.02 mg/kg IV	IV	Once	—	🌎 NA
As an analgesic	0.01-0.022 mg/kg IV ; up to 15 mg total	IV	Once	—	🌎 NA
As an analgesic	0.02-0.03 mg/kg IM	IM	Once	—	🌎 NA
As an analgesic	0.015-0.03 mg/kg IV	IV	Once	—	🌎 NA
Anesthetic induction in severely compromised horses	0.01-0.022 mg/kg IV	IV	Once	—	🌎 NA

As an analgesic: divide dose into 3-4 increments and give several minutes apart
Anesthetic induction in severely compromised horses: after approx. 45 minutes, may be necessary to 'top off' with another 1/3 of the original dose

豚

適応	用量	経路	頻度	期間	地域
To increase analgesia when used with ketamine/xylazine	0.075 mg/kg IV	IV	Once	—	🌎 NA

To increase analgesia when used with ketamine/xylazine: duration of anesthesia and recumbency: 20-30 minutes

用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。

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概要

オキシモルフォンは強力な半合成オピオイド作動薬であり、獣医学において主に鎮静/保定剤、鎮痛剤、および麻酔前投薬として使用されます。

効力： 重量比でモルヒネの約10倍の効力があります。
心血管系への影響： 心血管系への影響は通常臨床的に有意ではないため、心血管疾患の患者にとって比較的安全な選択肢となります。
ヒスタミン遊離： モルヒネやメペリジンとは異なり、静脈内投与時に有意なヒスタミン遊離を引き起こさないとされています。
臨床上のポイント： 乱用の可能性が高いため、スケジュールII（C-II）の規制薬物に指定されています。中等度から重度の疼痛に非常に有効ですが、獣医療においては入手可能性と費用が制限要因となることがあります。

作用機序

Oxymorphone acts primarily as a full agonist at mu (μ) opioid receptors, with some possible activity at delta (δ) receptors.

Pathway: Binds to G-protein coupled mu-opioid receptors in the CNS (limbic system, spinal cord, thalamus, midbrain) and peripheral tissues (GI tract, urinary tract) → inhibits adenylate cyclase → decreases intracellular cAMP → promotes opening of potassium channels and inhibits voltage-gated calcium channels → hyperpolarizes nociceptive neurons and inhibits the release of pain neurotransmitters (e.g., Substance P).
Effects: This results in profound analgesia, sedation, respiratory depression, and altered GI motility.

安全性・警告

禁忌

Hypersensitivity to narcotic analgesics
Patients receiving monoamine oxidase inhibitors (MAOIs)
Diarrhea caused by a toxic ingestion (until toxin is eliminated)
Scorpion stings (Centruroides sculpturatus and C. gertschi)

有害事象

Respiratory depression
Bradycardia
Decreased GI motility (constipation)
Panting (commonly seen in dogs)
Ataxia, hyperesthesia, and behavioral changes (cats at high dosages)
CNS excitement (horses)

注意事項

Extreme Caution: Use with extreme caution in patients with head injuries, increased intracranial pressure, acute abdominal conditions (e.g., colic, as it may obscure diagnosis), respiratory disease, or acute respiratory dysfunction.

Caution: Use cautiously in patients with hypothyroidism, severe renal insufficiency, adrenocortical insufficiency, preexisting bradyarrhythmias, and in geriatric or severely debilitated patients.
Species Specifics: In cats, high dosages can produce bizarre behavioral changes; concomitant use of a tranquilizer is recommended. In horses, opiates can mask behavioral and cardiovascular signs of mild colic.

医薬品相互作用

Butorphanol, Buprenorphine, Nalbuphine

Potentially could antagonize opiate effects

CNS Depressants

Additive CNS effects possible

Diuretics

Opiates may decrease efficacy in CHF patients

Monoamine Oxidase Inhibitors (MAOIs)

Extreme caution; may cause signs of opiate overdose

Muscle Relaxants, Skeletal

Oxymorphone may enhance effects

Phenothiazines

May antagonize analgesic effects and increase risk for hypotension

Tricyclic Antidepressants

Oxymorphone may exacerbate the effects of tricyclic antidepressants

Warfarin

Opiates may potentiate anticoagulant activity

監視

Respiratory rate/depth
CNS level of depression/excitation
Blood pressure (especially with IV use)
Analgesic activity
Cardiac rate

薬物動態

半減期

猫Prolonged due to deficient glucuronidation

吸収

Absorbed when given by IV, IM, SC, and rectal routes. Oral bioavailability is reduced due to a high first-pass effect. Analgesic efficacy usually occurs within 3-5 minutes after IV administration, and about 15 minutes after IM administration.

分布

Concentrates in the kidney, liver, and lungs; lower levels are found in the CNS. Crosses the placenta and is distributed into maternal milk.

代謝

Metabolized in the liver primarily by glucuronidation. Cats are deficient in this metabolic pathway, leading to prolonged half-lives.

消失

The kidneys excrete the glucuronidated metabolite.

過剰投与

Massive overdoses may produce profound respiratory and/or CNS depression in most species. Other effects may include cardiovascular collapse, hypothermia, and skeletal muscle hypotonia.

Antidote: Naloxone is the agent of choice in treating respiratory depression.
Management: In massive overdoses, naloxone doses may need to be repeated. Animals should be closely observed as naloxone's effects sometimes diminish before sub-toxic levels of oxymorphone are attained. Mechanical respiratory support should be considered in cases of severe respiratory depression.

製品

製剤

Injection
Extended-Release Oral Tablets
Suppositories

ヒト用医薬品

Oxymorphone HCl Oral Tablets: 5 mg & 10 mg; Opana®
Oxymorphone HCl Extended-Release Oral Tablets: 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30 mg & 40 mg; Opana® ER
Oxymorphone HCl for Injection: 1 mg/mL in 1 mL amps; Opana®

規制ステータス

規制データなし: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

保管・安定性

The injection should be stored protected from light and at room temperature (15-30°C); avoid freezing. Commercially available suppositories should be stored at temperatures between 2-15°C.

飼主向け情報

注射で投与する場合は、入院環境または専門家の直接の監督下で使用する必要があります。
安全上の警告： これは強力なオピオイドであり、規制薬物です。家庭用に処方された場合は、子供や他のペットの手の届かない場所に厳重に保管してください。

VetSheet医薬品リファレンスは獣医専門家の臨床意思決定支援を目的としており、専門的判断または製造業者の最新医薬品情報の代替にはなりません。