VetSheet

プロカインアミド

Procainamide

Procainamide hydrochloride

抗不整脈薬 (クラス1A)IVIMPO犬猫馬

別名: Pronestyl · Procanbid · Biocoryl · novocainamidum · procainamidi chloridum · procainamidi hydrochloridum

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

20-30 mg/kg PO q6-8hPO· q6-8h
— 🐕

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
Ventricular tachyarrhythmias2-4 mg/kg IV slowly (over two minutes) up to a total dose of 12-20 mg/kg until arrhythmia controlled and then a CRI may be started at 10-40 micrograms/kg/minuteIVIntermittent boluses then CRI—🌎 NA
Ventricular tachyarrhythmias20-30 mg/kg PO q6-8hPOq6-8h—🌎 NA
Acute management of SVTs6-8 mg/kg IV over 3 minutes or 6-20 mg/kg IMIV/IMOnce—🌎 NA
Chronic management of SVTs10-20 mg/kg PO q6-8hPOq6-8h—🌎 NA
Acute treatment of ventricular tachycardia10-15 mg/kg IV bolus over 1-2 minutes; if continued parenteral administration required may use a constant rate IV infusion at 25-50 micrograms/kg/minuteIVBolus then CRI—🌎 NA
Chronic treatment of ventricular tachycardia10-20 mg/kg PO q6hPOq6h—🌎 NA
Ventricular tachycardia6.6-8.8 mg/kg slowly IV over 5 minutes, then give as a CRI at 40-100 micrograms/kg/minuteIVBolus then CRI—🌎 NA
Chronic treatment of ventricular arrhythmias20-23 mg/kg PO q8hPOq8h—🌎 NA
Arrhythmias (using sustained-release tablets)20 mg/kg PO q8hPOq8h—🌎 NA
Arrhythmias (intravenous therapy)6-8 mg/kg IV bolus, 20-40 micrograms/kg/min CRIIVBolus then CRI—🌎 NA
Acute treatment of atrial fibrillation5-15 mg/kg IV slowly to effectIVTo effect—🌎 NA
Ventricular tachycardia (if lidocaine ineffective)20-50 micrograms/kg/min IV or 6-15 mg/kg IM q4-6hIV/IMCRI or q4-6h—🌎 NA
  • Ventricular tachyarrhythmias: Previous recommendations of 8-20 mg/kg PO q6-8h are almost certainly too low
  • Acute management of SVTs: After drugs have been used to slow AV nodal conduction (i.e., diltiazem)
  • Chronic management of SVTs: Higher dosages of up to 40 mg/kg q6h have been necessary to treat junctional SVTs in some dogs

猫

適応用量経路頻度期間地域
Chronic management of SVTs3-8 mg/kg PO q6-8hPOq6-8h—🌎 NA
Chronic management of SVTs1-2 mg/kg slowly IV; 10-20 micrograms/kg/minute constant rate IV infusionIVBolus then CRI—🌎 NA
Chronic management of SVTs7.5-20 mg/kg q 6-8hPOq6-8h—🌎 NA

馬

適応用量経路頻度期間地域
Atrial fibrillation / Ventricular tachycardia1 mg/kg/min IV, not too exceed 20 mg/kg (20 minutes) total doseIVOnce20 minutes max🌎 NA
Atrial fibrillation / Ventricular tachycardia25-35 mg/kg PO q8hPOq8h—🌎 NA
V-Tach1 mg/kg/minute IV up to a total dose of 20 mg/kg; or 25-35 mg/kg PO q8hIV/POOnce or q8h—🌎 NA
  • Atrial fibrillation / Ventricular tachycardia: Not as effective as quinidine for atrial fibrillation

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

プロカインアミドは、局所麻酔薬プロカインと構造的に関連する​クラス1A抗不整脈薬​です。獣医学では主に、​心室性頻脈性不整脈​（心室期外収縮 [VPC] や心室頻拍など）および特定の​上室性頻拍​（SVT）の管理に使用されます。

心房性および心室性不整脈の両方に対する幅広い活性スペクトルを持つため、広いQRS波を伴う頻拍が上室性か心室性か明確に特定できない場合、理想的な第一選択の静脈内治療薬と見なされることがよくあります。

​臨床のポイント:​ 人間とは異なり、犬はアセチル化能力が低く、活性代謝物であるN-アセチルプロカインアミド（NAPA）を十分に生成しません。したがって、犬の治療薬物モニタリングはプロカインアミド濃度のみに焦点を当てるべきです。

作用機序

Procainamide acts primarily as a fast sodium channel blocker (Class 1A), similar to quinidine.

  • ​Phase 0 Blockade:​ Slows the influx of sodium during Phase 0 depolarization of the cardiac action potential.
  • ​→​ Prolongs the refractory period in both the atria and ventricles.
  • ​→​ Decreases myocardial excitability and depresses automaticity and conduction velocity.
  • ​Anticholinergic Effects:​ Exhibits mild vagolytic properties which may cause slight increases in heart rate or unpredictable rate changes.
  • ​ECG Effects:​ Commonly causes widening of the QRS complex and prolongation of the PR and QT intervals.

安全性・警告

禁忌

  • Myasthenia gravis
  • Hypersensitivity to procainamide, procaine, or chemically related drugs
  • Systemic lupus erythematosus (SLE) in humans (unknown in dogs)
  • Torsade de pointes
  • 2nd or 3rd degree heart block (unless artificially paced)
  • Doberman pinschers and boxers with dilated cardiomyopathy (relative - proarrhythmic risk)
  • Dogs with subaortic stenosis (relative - proarrhythmic risk)

有害事象

  • Anorexia
  • Vomiting
  • Diarrhea
  • Weakness
  • Hypotension (especially with rapid IV injection)
  • Negative inotropism
  • Widened QRS complex
  • Prolonged QT interval
  • AV block
  • Multiform ventricular tachycardias
  • Fevers
  • Leukopenias

注意事項

Use with extreme caution in patients with cardiac glycoside intoxication. Use with caution in patients with significant hepatic or renal disease, or congestive heart failure (CHF). Dosages should usually be reduced in patients with renal failure, CHF, or those who are critically ill.

​Warning:​ Profound hypotension can occur if injected too rapidly IV. Do not use in Doberman pinschers and boxers with dilated cardiomyopathy or dogs with subaortic stenosis as it may be proarrhythmic and induce sudden death.

医薬品相互作用

Amiodarone

May increase procainamide levels; procainamide dose may need to be reduced

Anticholinesterase agents (e.g., pyridostigmine, neostigmine)

Procainamide may antagonize effects in patients with myasthenia gravis

Cimetidine

May increase procainamide levels

Hypotensive drugs

Procainamide may enhance hypotensive effects

Lidocaine

Toxic effects may be additive, and cardiac effects unpredictable

Neuromuscular blocking agents

Procainamide may potentiate or prolong the neuromuscular blocking activity

Quinidine

Toxic effects may be additive, and cardiac effects unpredictable

Phenytoin

Toxic effects may be additive, and cardiac effects unpredictable

Propranolol

Toxic effects may be additive, and cardiac effects unpredictable

Ranitidine

May increase procainamide levels

Trimethoprim

May increase procainamide levels

監視

  • ECG (continuously with IV dosing)
  • Blood pressure (during IV administration)
  • Clinical signs of toxicity (GI signs, weakness)
  • Serum drug levels (Trough levels for oral therapy. Note: Request lab to not run NAPA for dogs. Target range: 3-8 to 8-20 mcg/mL in dogs; 4-10 mcg/mL in horses)

薬物動態

半減期

犬2-3 hours

吸収

Onset of action is practically immediate after IM or IV administration. Oral bioavailability in dogs is approximately 85% with an absorption half-life of 0.5 hours, though highly variable. Food, delayed gastric emptying, or decreased stomach pH may delay oral absorption.

分布

Highest distribution into the CSF, liver, spleen, kidneys, lungs, heart, and muscles. Volume of distribution in dogs is approximately 1.4-3 L/kg. Protein binding is low (approximately 15% in dogs). Crosses the placenta and is excreted into milk.

代謝

In humans, metabolized to the active metabolite N-acetyl-procainamide (NAPA). Dogs, however, do not form appreciable amounts of NAPA as they are unable to appreciably acetylate aromatic and hydrazine amino groups.

消失

In dogs, approximately 90% (50-70% unchanged) of an intravenous dose is excreted in the urine as procainamide and metabolites within 24 hours.

過剰投与

Clinical signs of overdosage can include hypotension, lethargy, confusion, nausea, vomiting, and oliguria. Cardiac signs may include widening of the QRS complex, junctional tachycardia, ventricular fibrillation, or intraventricular conduction delays.

  • ​Oral Ingestion:​ Emptying of the gut and charcoal administration may be beneficial to remove unabsorbed drug.
  • ​Hypotension:​ IV fluids, plus dopamine, phenylephrine, or norepinephrine could be considered.
  • ​Cardiotoxicity:​ A 1/6 molar intravenous infusion of sodium lactate may be used in an attempt to reduce cardiotoxic effects.
  • ​Elimination:​ Forced diuresis using fluids and diuretics along with reduction of urinary pH can enhance renal excretion.
  • ​AV Block:​ Temporary cardiac pacing may be necessary should severe AV block occur.

製品

製剤

  • Injection solution
  • Oral capsules
  • Extended-release oral tablets

ヒト用医薬品

  • Procainamide HCl Injection Solution: 100 mg/mL in 10 mL multi-dose vials and 500 mg/mL in 2 mL vials
  • Procainamide HCl Oral Capsules: 250 mg & 375 mg
  • Procainamide HCl Extended-Release Oral Tablets: 250 mg, 500 mg, & 1000 mg (Note: Not recommended for initial therapy in veterinary medicine)

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

Store at room temperature. Refrigeration may retard the development of oxidation, but the solution may be stored at room temperature. The solution may be used if the color is no darker than a light amber.

飼主向け情報

  • ​投与方法:​ 経口薬は、安定した血中濃度を維持するため、昼夜を問わず等間隔で投与する必要があります。
  • ​食事:​ 獣医師の指示がない限り、空腹時（食事の少なくとも1時間前）に薬を与えてください。
  • ​モニタリング:​ ペットの症状が悪化した場合、または中毒の臨床症状（嘔吐、下痢、重度の無気力、脱力感など）が見られた場合は、直ちに獣医師に連絡してください。

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。