VetSheet

ジルチアゼム

Diltiazem

Diltiazem Hydrochloride

カルシウムチャネル遮断薬 / クラスIV抗不整脈薬POIV犬猫フェレット

別名: Cardizem CD · Cardizem LA · Dilacor XR · Cartia XT · Tiazac · Diltia XT · Taztia XT · Dilt-CD · Hypercard · Adizem · Angitil · Dilcardia · Dilzem · Slozem · Tildiem · Viazem · Zemret · CRD-401 · diltiazemi hydrochloridum · latiazem hydrochloride · MK-793 · Diltiazem 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

Initially, 0.5 mg/kg PO q8h, if response not adequate can increase to 1 mg/kg PO q8h and finally, to 1.5 mg/kg PO q8h.PO· q8h
— 🐕

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
Decreasing ventricular rate in dogs with atrial fibrillationInitially, 0.5 mg/kg PO q8h, if response not adequate can increase to 1 mg/kg PO q8h and finally, to 1.5 mg/kg PO q8h.POq8h—🌎 NA
Acute treatment of supraventricular tachycardia0.05 mg/kg IV administered over 1-2 minutes. May repeat this dose up to two times, with 5 minutes between doses. Some cardiologists use a dose of 0.25 mg/kg administered over 5 minutes.IVAs directed—🌎 NA
Chronic treatment of supraventricular tachycardiaInitially, 1 mg/kg PO q8h and titrated upward to a maximum of 4 mg/kg PO q8h.POq8h—🌎 NA
Acute treatment of atrial tachycardia0.05-0.15 mg/kg slowly IV, repeat every 5 minutes to effect or until a total dose of 0.1-0.3 mg/kg; OR give 0.5 mg/kg PO followed by 0.25 mg/kg PO every hour until conversion or a total oral dose of 1.5-2 mg/kg has been given.IV/POAs directed—🌎 NA
Chronic treatment of atrial tachycardiaMay give an initial dose of 0.5 mg/kg PO q8h up to 2 mg/kg.POq8h—🌎 NA
Emergency treatment of supraventricular tachyarrhythmiasInitially, 0.25 mg/kg IV bolus given over 2 minutes; subsequent 0.25 mg/kg boluses may be repeated at 15 minute intervals until conversion occurs or to a maximum (total) dose of 0.75 mg/kg.IVq15min—🌎 NA
Adjunctive treatment of pulmonary hypertension1-2 mg/kg PO three times daily.POTID—🌎 NA
Emergency management of hypertension (when nitroprusside unavailable)0.5 mg/kg PO q6hPOq6h—🌎 NA
Supraventricular tachyarrhythmias / Atrial fibrillation0.05-0.25 mg/kgIVsingle dose over 1-2 min—🌍 EU
Supraventricular tachyarrhythmias / Atrial fibrillation0.5-2.0 mg/kgPOq8h—🌍 EU
Supraventricular tachyarrhythmias / Atrial fibrillationup to 3.0 mg/kgPOq12h—🌍 EU
Supraventricular tachyarrhythmias / Atrial fibrillation10 mg/kgPOq24h—🌍 EU
Refractory supraventricular tachyarrhythmiasup to 4 mg/kgPOq8h—🌍 EU
  • Decreasing ventricular rate in dogs with atrial fibrillation: Digoxin most commonly used first. In general, do not use with beta blocker.
  • Chronic treatment of supraventricular tachycardia: Doses from 2-4 mg/kg q8h should probably not be given to dogs that have moderate to severe myocardial failure or with significant cardiac compromise.
  • Emergency management of hypertension (when nitroprusside unavailable): If blood pressure not controlled, may add a betablocker (e.g., atenolol).
  • Supraventricular tachyarrhythmias / Atrial fibrillation: Lower doses are preferred in the presence of heart failure.
  • Supraventricular tachyarrhythmias / Atrial fibrillation: For modified-release (-MR) products.
  • Supraventricular tachyarrhythmias / Atrial fibrillation: For sustained/extended release (-SR) preparations (little evidence established).
  • Supraventricular tachyarrhythmias / Atrial fibrillation: For long-acting preparations; little experience with such formulations in animals.

猫

適応用量経路頻度期間地域
Treatment of hypertrophic cardiomyopathy (Option A)7.5 mg (total dose) PO q8-12h; Long-acting forms: Cardizem CD Capsules: 10 mg/kg once daily. Dilacor XR Capsules: 15-30 mg total dose q12-24h.POq8-24h—🌎 NA
Treatment of hypertrophic cardiomyopathy (Option B)1.75-2.5 mg/kg PO q8h or sustained release (Dilacor) dosed at 30 mg (total dose) PO q12hPOq8-12h—🌎 NA
Treatment of hypertrophic cardiomyopathy (Option C)7.5-15 mg (total dose) per cat PO q8h. Alternatively, the sustainedrelease products Cardizem CD at 45 mg (total dose) PO q24h or Dilacor XR at 30 mg (total dose; 1/2 of one of the 60 mg tablets found within the capsule) PO q12h can be used.POq8-24h—🌎 NA
Treatment of hypertrophic cardiomyopathy (Option D)If using standard release formulations: 1-2.5 mg/kg PO q8h; if using sustained release formations: 30-60 mg (total dose per cat) q24h.POq8-24h—🌎 NA
Treatment of hypertrophic cardiomyopathy (Option E)Dilacor XR 30 mg/cat PO q24h.POq24h—🌎 NA
Emergency treatment of supraventricular tachyarrhythmiasInitially, 0.25 mg/kg IV bolus given over 2 minutes; subsequent 0.25 mg/kg boluses may be repeated at 15 minute intervals until conversion occurs or to a maximum (total) dose of 0.75 mg/kg.IVq15min—🌎 NA
Acute management of supraventricular tachyarrhythmias0.125-0.35 mg/kg IVIVAs directed—🌎 NA
Chronic management of supraventricular tachyarrhythmias7.5 mg (per cat) PO q8hPOq8h—🌎 NA
Emergency management of hypertension (when nitroprusside unavailable)0.5 mg/kg PO q6hPOq6h—🌎 NA
Supraventricular tachyarrhythmias / Hypertrophic cardiomyopathy0.05-0.25 mg/kgIVsingle dose over 1-2 min—🌍 EU
Supraventricular tachyarrhythmias / Hypertrophic cardiomyopathy0.5-2.5 mg/kgPOq8h—🌍 EU
  • Treatment of hypertrophic cardiomyopathy (Option A): Some cats tolerate 60 mg daily, but vomiting may be a problem.
  • Treatment of hypertrophic cardiomyopathy (Option D): Also indicated for supraventricular arrhythmias.
  • Treatment of hypertrophic cardiomyopathy (Option E): If cat has minimal tachycardia and a loud S4 gallop, many prefer using diltiazem (over a beta blocker).
  • Chronic management of supraventricular tachyarrhythmias: Used in combination with digoxin for patients with CHF unless cat has hypertrophic cardiomyopathy and atrial fib, then digoxin not used.
  • Emergency management of hypertension (when nitroprusside unavailable): If blood pressure not controlled, may add a betablocker (e.g., atenolol).
  • Supraventricular tachyarrhythmias / Hypertrophic cardiomyopathy: Alternatively, one 10 mg tablet for cats of 3-6.25 kg PO q8h.

フェレット

適応用量経路頻度期間地域
Hypertrophic cardiomyopathy2-7.5 mg/kg PO twice daily; adjust as necessary.POBID—🌎 NA
  • Hypertrophic cardiomyopathy: May result in heart block.

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。

診察中ですか？VetSheet の AI が薬剤・用量・投与期間を構造化された診察記録に直接記入します。VetSheet の仕組みを見る

概要

ジルチアゼムは​非ジヒドロピリジン系カルシウムチャネル遮断薬​および​クラスIV抗不整脈薬​であり、獣医療では主に猫の上室性頻拍（SVT）、全身性高血圧、肺高血圧症、肥大型心筋症（HCM）の管理に使用されます。

  • ​心血管作用：​ 主に房室結節の伝導を遅らせ、血管拡張を促進することで作用し、心房細動の心拍数コントロールに非常に有効です。
  • ​臨床的有用性：​ 歴史的には猫のHCM治療の基本でしたが、近年この適応での使用は他の治療法に取って代わられつつあります。しかし、頻脈性不整脈の治療には依然として重要な薬剤です。
  • ​臨床のポイント：​ 強力な末梢血管拡張薬であるジヒドロピリジン系（アムロジピンなど）とは異なり、ジルチアゼムは心刺激伝導系への影響が強いため、リズムコントロールには優れていますが、重度の全身性高血圧に対する降圧作用は弱いです。

作用機序

Diltiazem exerts its effects by binding to the alpha-1 subunit of L-type voltage-gated calcium channels.

  • ​Mechanism:​ Inhibits transmembrane influx of extracellular calcium ions → decreases intracellular calcium in myocardial cells and vascular smooth muscle.
  • ​Cardiac Conduction:​ Slows AV node conduction and prolongs refractory times (negative dromotropic effect). It rarely affects SA node conduction except in sick sinus syndrome.
  • ​Vasodilation:​ Relaxes vascular smooth muscle → dilates main systemic and coronary arteries → reduces total peripheral resistance, blood pressure, and cardiac afterload.
  • ​Inotropy:​ Can cause mild negative inotropic effects, though rarely of clinical significance compared to verapamil.

安全性・警告

禁忌

  • Severe hypotension (<90 mm Hg systolic)
  • Sick sinus syndrome (unless functioning pacemaker is in place)
  • 2nd or 3rd degree AV block (unless functioning pacemaker is in place)
  • Acute myocardial infarction
  • Radiographically documented pulmonary congestion
  • Hypersensitivity to diltiazem
  • Second or third degree AV block
  • Marked hypotension
  • Acute or decompensated congestive heart failure (relative contraindication)

有害事象

  • Dogs: Bradycardia (most prominent)
  • Cats: Vomiting (especially with 60 mg sustained-release pellets)
  • Lethargy
  • Anorexia / GI distress
  • Hypotension
  • Heart block or rhythm disturbances
  • CNS effects
  • Skin rashes
  • Elevations in liver enzymes
  • Bradycardia (most common in dogs)
  • Vomiting (most common in cats)
  • AV block

注意事項

​Warning:​ Use with extreme caution in geriatric patients, those with heart failure (especially if receiving beta-blockers), or patients with hepatic or renal impairment.

  • ​IV Administration:​ If giving direct IV push, administer slowly over at least two minutes to prevent acute hypotension or collapse.
  • ​Pregnancy:​ Potential teratogen at high doses (FDA Category C). Use only when benefits outweigh risks.
  • ​Nursing:​ Excreted in milk at concentrations approximating serum levels; use with caution.

医薬品相互作用

Anesthetics, General

May increase cardiac depressant effects of diltiazem.

Benzodiazepines

Diltiazem may increase benzodiazepine levels.

Beta-Blockers

May increase the likelihood of bradycardia, AV block, or CHF. Diltiazem may substantially increase the bioavailability of propranolol.

Buspirone

Diltiazem may increase buspirone levels.

Cisapride

Could potentially increase risk for increased QT intervals.

DigoxinModerate

Data conflicts regarding pharmacokinetic effects; diligent monitoring of digoxin serum concentrations is required.

CimetidineModerate

May increase plasma diltiazem concentrations; increased monitoring warranted.

Ranitidine

May affect diltiazem concentrations, but to a lesser extent than cimetidine.

Cyclosporine

Diltiazem may increase cyclosporine serum concentrations; monitoring and dosage adjustments may be required.

Rifampin

May decrease diltiazem levels.

Quinidine

Diltiazem may increase quinidine serum concentrations; monitoring and dosage adjustments may be required.

Beta-adrenergic blockers (e.g., propranolol)Major

Additive negative inotropic and chronotropic effects. Co-administration is not recommended.

Calcium saltsModerate

May adversely affect the activity of diltiazem.

Vitamin DModerate

May adversely affect the activity of diltiazem.

TheophyllineMajor

Diltiazem enhances the effect of theophylline, which may lead to toxicity.

CiclosporinModerate

Diltiazem may affect ciclosporin concentrations.

Highly protein-bound agentsMinor

Diltiazem may displace these agents from plasma proteins.

VincristineMajor

Diltiazem may increase intracellular vincristine levels by inhibiting outflow of the drug from the cell.

監視

  • ECG / Heart rate
  • Blood pressure
  • Adverse effects (vomiting, lethargy)
  • Heart rate and rhythm (ECG)
  • Renal and hepatic function (periodically)
  • Serum digoxin levels (if used concurrently)

薬物動態

半減期

猫~2 hours (standard release); 411 +/- 59 minutes (Cardizem CD)馬~90 minutes犬~3 hours

吸収

In humans, ~80% absorbed orally but high first-pass effect limits systemic bioavailability to ~50%. In cats, bioavailability is 50-80% (peak at 45 mins); sustained-release products vary (Cardizem CD 22-59%, Dilacor XR ~94%). In dogs, bioavailability is low (~25%).

分布

Approximately 70-75% bound to serum proteins. Enters milk in concentrations approximating plasma levels.

代謝

Rapidly and almost completely metabolized in the liver to several metabolites, including two active ones.

消失

Renal impairment may slightly increase half-lives.

過剰投与

The oral LD50 in dogs is >50 mg/kg.

  • ​Clinical Signs:​ GI signs, heart block, severe bradycardia, hypotension, CNS depression, and heart failure.
  • ​Treatment:​
    • Gut emptying protocols if recent ingestion.
    • ​Bradycardia/AV Block:​ Atropine. If unresponsive to vagal blockade, cautious use of isoproterenol. Fixed block may require temporary transvenous cardiac pacing.
    • ​Hypotension/Heart Failure:​ Inotropics (dobutamine, dopamine, isoproterenol) and pressors (norepinephrine).
    • ​Antidote:​ A slow intravenous calcium infusion (1 mL/10 kg body weight of 10% calcium gluconate) may be useful for severe acute toxicity.

製品

製剤

  • Oral Tablets
  • Oral Extended/Sustained Release Capsules and Tablets
  • Injection (solution and powder for reconstitution)
  • 10 mg modified-release (-MR) tablets
  • 60 mg modified-release (-MR) tablets
  • 60 mg, 90 mg, 120 mg sustained-release (-SR) capsules
  • 10 mg/ml injectable solution

動物用医薬品

  • Hypercard 10 mg modified-release tablets

ヒト用医薬品

  • Diltiazem Oral Tablets: 30 mg, 60 mg, 90 mg, & 120 mg (Cardizem, generic)
  • Diltiazem Extended/Sustained Release Capsules & Tablets: 60 mg, 90 mg, 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, 420 mg (Cardizem CD & LA, Cartia XT, Dilacor XR, Tiazac, Diltia XT, Taztia XT, Dilt-CD & XR, generic)
  • Diltiazem Injection: 5 mg/mL in 5 mL, 10 mL, 25 mL vials
  • Diltiazem Powder for Injection: 25 mg in single-use containers
  • Adizem
  • Angitil
  • Dilcardia SR (60 mg, 90 mg, 120 mg capsules)
  • Diltiazem generic
  • Dilzem
  • Slozem
  • Tildiem
  • Viazem
  • Zemret

規制ステータス

European Union✓ 承認済み処方箋医薬品EMA
🐈 Cats

POM-V, POM. Hypercard is authorized for veterinary use.

United Kingdom✓ 承認済み処方箋医薬品VMD
🐈 Cats

POM-V, POM.

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

保管・安定性

Oral products should be stored at room temperature in tight, light-resistant containers. Powder for injection should be stored between 15-30°C; discard after 24 hours once reconstituted.

飼主向け情報

ジルチアゼムは、ペットの不整脈や高血圧の治療に使用される薬です。

  • ​投与方法：​ 獣医師の指示通りに正確に投与してください。獣医師の特別な指示がない限り、徐放性カプセルを​砕いたり噛ませたりしないでください​（Dilacor XRなどの特定のブランドは、獣医師の厳密な指導の下でカプセルを開けて中の錠剤を使用することがあります）。
  • ​副作用：​ 無気力、虚弱、失神、または嘔吐（特に猫でよく見られます）の兆候がないか観察してください。ペットが倒れたり、異常に疲れているように見える場合は、すぐに獣医師に連絡してください。
  • ​服薬の継続：​ 心臓の薬は、投与スケジュールを厳密に守る必要があります。獣医師に相談せずに、投与を飛ばしたり、急に薬をやめたりしないでください。

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。