ヒドロコドン
ヒドロコドンはフェナントレン誘導体の**オピオイド作動薬**であり、獣医療では主に犬の強力な**鎮咳薬**として使用されます。 * **主な適応症：** 気管虚脱、気管支炎、犬伝染性気管気管支炎（ケンネルコフ）などに関連する、激しい乾性咳嗽の管理。 * **行動治療：** オピオイド関連の行動問題（舐性肉芽腫、常同行動など）の治療に時折使用され、外因性オピオイドを提供することで自己刺激行動を減らします。 * **鎮痛作用：** アセトアミノフェンを含む配合剤は、犬の中等度の経口鎮痛に使用できます。 > **重大な警告：** アセトアミノフェンを含む配合剤（Vicodin®、Lortab®など）は、致命的なアセトアミノフェン中毒を引き起こすため、**猫には絶対に使用してはいけません**。
作用機序: Hydrocodone acts primarily by binding to **mu-opioid receptors** in the central nervous system. * **Antitussive Effect:** Direct suppression of the cough reflex at the **cough center** in the **medulla oblongata**. * **Analgesic Effect:** Binds to pre- and post-synaptic **mu-receptors** in the brain and spinal cord → inhibits release of nociceptive neurotransmitters (like Substance P) → hyperpolarizes neurons → decreases excitability and pain transmission. * **Respiratory Effects:** Tends to have a drying effect on respiratory mucosa, increasing the viscosity of secretions. The addition of homatropine methylbromide (an anticholinergic) in some formulations enhances this drying effect.
動物種別の用量
- For adjunctive treatment of opioid-related stereotypies · 1.25-5 mg per cat PO q12h · PO · q12h · Do NOT use any product that contains acetaminophen.
- For cough · 0.22 mg/kg PO q6-12h · PO · q6-12h · Goal is to suppress coughing without causing excessive sedation
- As an analgesic using fixed dose combination products with acetaminophen · 0.22-0.5 mg/kg of the hydrocodone component PO q8-12h · PO · q8-12h · Do not exceed 15 mg/kg of the acetaminophen component q8h.
- For cough using Hycodan (or equivalent) · ¼ to 1 tablet (5 mg) once to 4 times daily · PO · q6-24h · In small and medium sized dogs.
- For lick granulomas · 5-10 mg (1-2 tablets) per 20 kg of body weight PO three times daily · PO · TID
- For adjunctive treatment of opioid-related stereotypies, lick granuloma · 0.22-0.25 mg/kg PO q8-12h · PO · q8-12h · Supplies exogenous opioids to decrease the need for self-stimulation.
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 narcotic analgesics
- Patients receiving monoamine oxidase inhibitors (MAOIs, e.g., selegiline)
- Diarrhea caused by toxic ingestion (until toxin is eliminated)
- Acetaminophen-containing products MUST NOT be used in cats
有害事象
- Sedation
- Constipation (especially with chronic therapy)
- Vomiting
- Gastrointestinal disturbances
- Masking of clinical signs of underlying respiratory disease
薬物相互作用
- Acepromazine · May cause additive hypotension in dogs with collapsing trachea
- Anticholinergic Drugs · May cause additive anticholinergic effects
- Antidepressants (Tricyclic & MAOIs) · May potentiate the adverse effects associated with the antidepressant
- CNS Depressants (anesthetics, antihistamines, phenothiazines, barbiturates, tranquilizers) · May cause increased CNS or respiratory depression
モニタリング
- Clinical efficacy (reduction in cough frequency/severity, pain relief)
- Adverse effects (excessive sedation, constipation, respiratory depression)
過量投与
Massive overdose primarily causes **CNS, cardiovascular, and respiratory depression** secondary to opiate effects. * **Treatment:** If ingestion was recent, empty the gut using standard protocols. Administer **naloxone** to reverse opioid effects as necessary. * **Note on Homatropine:** The homatropine ingredient in some formulations may cause anticholinergic effects, but its relatively low toxicity usually does not require specific treatment.
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。