Adecard6 mg/2 ml

Paroxysmal Supraventricular Tachycardia (PSVT)

Adecard is established (FDA-approved) for the rapid conversion of paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm, including PSVT associated with accessory bypass tracts (e.g., Wolff-Parkinson-White syndrome).

Diagnostic Aid in Undifferentiated Tachycardia

Adecard is established as a diagnostic aid when the mechanism of a wide- or narrow-complex tachycardia is uncertain; by producing transient AV block, it can unmask an underlying atrial flutter or atrial fibrillation that was previously obscured by a fast ventricular rate.

Pharmacologic Cardiac Stress Testing

A higher-dose, continuous-infusion formulation of Adecard is established as a coronary vasodilator stress agent for myocardial perfusion imaging in patients who cannot exercise adequately for a standard exercise stress test.

Not Indicated For

Adecard is not indicated for ongoing/maintenance antiarrhythmic therapy, and it does not convert atrial fibrillation, atrial flutter, or ventricular tachycardia to sinus rhythm, although it may transiently slow the ventricular rate enough to aid diagnosis of these rhythms.

Adenosine injection, USP, contains Adenosine 3 mg per mL as the active ingredient, supplied as a sterile, preservative-free, ready-to-use solution for intravenous use. It is available in low-volume vials or prefilled syringes (e.g., 6 mg/2 mL, 12 mg/4 mL) for rapid IV bolus use in arrhythmia termination, and in larger-volume vials (e.g., 30 mg/10 mL) intended for continuous IV infusion during pharmacologic cardiac stress testing.

Adecard is an endogenous nucleoside, a naturally occurring compound found in every cell of the body, used in the hospital setting as a rapid-acting intravenous antiarrhythmic agent and as a pharmacologic stress agent for cardiac imaging. When given as a rapid IV bolus, Adecard briefly and profoundly slows electrical conduction through the AV node, which can interrupt the abnormal electrical circuit responsible for paroxysmal supraventricular tachycardia (PSVT) and restore a normal heart rhythm within seconds. Because Adecard is taken up and broken down almost immediately by red blood cells and vascular endothelium, its effects last only a few seconds, which is why it must be given as a fast IV push followed immediately by a saline flush, in a monitored setting with resuscitation equipment on hand. Adecard is not a medicine that patients take on their own; it is administered only by trained healthcare professionals in a hospital, emergency department, or cardiac catheterization/testing setting.

Antiarrhythmic Agent (Endogenous Purine Nucleoside); Cardiac Diagnostic / Pharmacologic Stress Agent

Adenosine has an extremely short biological half-life, generally under 10 seconds, because it is rapidly taken up byerythrocytes and vascular endothelial cells and metabolized by adenosine deaminase and adenosine kinase; very little is excreted unchanged.This ultra-short half-life is why Adenosine's electrophysiologic effects on the AV node resolve within seconds and why repeat or escalatingdoses can be given close together if an initial dose is ineffective. Adenosine's clearance is cellular and enzymatic rather than hepatic orrenal, so its pharmacokinetics are not significantly altered by liver or kidney impairment.

• Administer Adecard only in a setting with continuous ECG monitoring and full resuscitation equipment, including a defibrillator, immediately available.
• Give as a rapid IV bolus into a large, proximal vein (e.g., antecubital), immediately followed by a rapid saline flush of about 20 mL, so the dose reaches the central circulation before it is broken down.
• Do not administer through a small-gauge or distal IV line, as this can allow the drug to be inactivated before it reaches the heart, making the dose ineffective.
• Warn the patient just before injection that brief flushing, chest pressure, shortness of breath, or a strange sense of impending doom are expected, transient effects.
• For pharmacologic stress-test infusion, administer via a calibrated infusion pump with continuous ECG and blood pressure monitoring throughout the infusion and for a period afterward.
• Adecard is for professional administration only and is never given as a take-home or self-administered dose.

• Dipyridamole: blocks cellular uptake of Adecard and potentiates its effects; a substantially reduced Adecard dose may be needed if used concurrently, and dipyridamole is often withheld before stress testing.
• Methylxanthines (caffeine, theophylline, aminophylline): competitively antagonize Adecard at the receptor level, reducing its effectiveness; higher Adecard doses may be needed, and patients undergoing pharmacologic stress testing are typically instructed to avoid caffeine and to hold theophylline-containing medicines beforehand per institutional protocol.
• Carbamazepine: may increase the degree of heart block produced by Adecard.
• Digoxin, particularly with verapamil: rare reports of ventricular fibrillation when Adecard is given to patients on digoxin, especially in combination with verapamil; use with caution.
• Other AV-nodal blocking drugs (e.g., beta-blockers, calcium channel blockers): combined use with Adecard may increase the risk or degree of bradycardia or heart block.

Common Effects (Transient, Usually Seconds to About a Minute)

• Flushing
• Chest pain, pressure, or discomfort
• Shortness of breath (dyspnea)
• Lightheadedness or headache
• Nausea
• A sense of impending doom
• Tingling in the arms
• Brief new rhythm disturbances (extra beats, sinus bradycardia, or transient high-degree AV block) as an expected pharmacologic effect

Serious Effects (Seek Immediate Medical Attention)

• Severe or prolonged wheezing/bronchospasm, especially in patients with asthma (see Precautions and Warnings)
• Prolonged high-degree AV block or asystole that does not resolve spontaneously
• Severe or persistent low blood pressure
• Chest pain suggestive of myocardial ischemia
• A new, sustained ventricular arrhythmia
• Signs of a severe allergic reaction

Pregnancy

Adecard should be used in pregnancy only if clearly needed and the potential benefit justifies the potential risk to the fetus, and onlyunder direct medical supervision in a monitored hospital setting; formal controlled studies of Adecard in pregnant women are lacking. Basedon case reports and cardiac-arrest/resuscitation guidance for pregnancy, Adecard has been used to terminate maternal PSVT when vagalmaneuvers fail, reflecting its extremely short half-life, but this should remain a physician's decision made case by case.

Breastfeeding

Published data on Adecard use during breastfeeding are limited. Because Adecard has an extremely short half-life of only seconds and isgiven as a single hospital dose or short infusion rather than a repeated take-home medicine, significant infant exposure through breast milkis not expected; even so, a physician should be consulted regarding breastfeeding around the time Adecard is administered.

• Monitored setting required: Adecard should be given only where continuous ECG monitoring and full resuscitation equipment, including a defibrillator, are immediately available, because transient but potentially significant AV block, sinus bradycardia, or brief asystole is an expected pharmacologic effect that must be anticipated.
• Bronchospasm risk: Adecard can cause severe bronchospasm, particularly in patients with asthma or other bronchoconstrictive lung disease; see Contraindications for its use as a stress agent in this population.
• Accessory pathway arrhythmias (e.g., Wolff-Parkinson-White syndrome): in rare cases Adecard can increase conduction down an accessory pathway during atrial fibrillation or flutter, leading to a markedly increased ventricular response or, rarely, ventricular fibrillation; resuscitation equipment must be available.
• New arrhythmias at conversion: transient new rhythms, including a brief period of asystole, can occur at the moment PSVT converts to sinus rhythm; these are usually self-limited within seconds.
• Heart transplant recipients: patients with a recently transplanted, denervated heart may show markedly heightened sensitivity to Adecard; a substantially reduced dose should be considered with close monitoring.
• Not definitive therapy for other arrhythmias: Adecard will not convert atrial fibrillation, atrial flutter, or ventricular tachycardia to sinus rhythm and should not be relied upon as treatment for these rhythms; see Indications.

Because Adecard has an extremely short half-life, generally under 10 seconds, most excessivepharmacologic effects (marked flushing, hypotension, significant bradycardia or high-degree AV block, dyspnea, or bronchospasm) resolverapidly on their own once the dose or infusion is stopped, and treatment is primarily supportive with continuous monitoring. If effects aresevere or persistent, the treating physician may use a xanthine derivative (e.g., aminophylline or theophylline), which directly antagonizesAdecard at the receptor level, along with other supportive measures such as IV fluids for hypotension, atropine for persistent symptomaticbradycardia, or temporary pacing if needed. Adecard is used only in a monitored clinical setting, so any suspected excessive effect ismanaged immediately by the treating medical team; contact emergency services or a poison control center if excessive effects are suspectedoutside a monitored setting.

Store Adecard injection at controlled room temperature, 20°C to 25°C (68°F to 77°F); do not refrigerate, as refrigeration can cause the solution to crystallize. If crystals are seen, warm the vial or syringe to room temperature to redissolve them, and confirm the solution is clear and free of visible particles before use. As with all injectable medicines, Adecard should be kept out of reach of children and used only by trained healthcare personnel in a hospital or clinical setting; discard any unused portion, as it is a single-use, preservative-free product.

• Heart transplant recipients: increased sensitivity to Adecard due to cardiac denervation; reduced initial dosing and close monitoring are recommended.
• Renal impairment: no dose adjustment is generally required, as Adecard's clearance from the bloodstream is cellular and enzymatic rather than renal.
• Hepatic impairment: no dose adjustment is generally required, for the same reason.
• Elderly patients: no specific dose adjustment beyond standard weight-based/clinical dosing, though pre-existing cardiac conduction disease should be assessed before use.
• Pregnant and breastfeeding women: see Pregnancy and Lactation for detailed guidance.
• Children: see Pediatric Uses for weight-based emergency dosing.

Adecard is a short-acting, hospital-administered medicine, not one taken on an ongoing or outpatientbasis. For PSVT, it is given as one or more rapid IV bolus doses within a single treatment episode, typically an initial dose followed, ifneeded, by one or two escalating doses a couple of minutes apart, to restore normal rhythm; it is not continued afterward as maintenancetherapy. For pharmacologic cardiac stress testing, Adecard is given as a single continuous IV infusion, typically over about 6 minutes, aspart of one imaging session.

Antiarrhythmic Agent (endogenous purine nucleoside, AV-nodal blocking agent); Coronary Vasodilator / Pharmacologic Cardiac Stress Agent

Adenosine acts on cell-surface adenosine (P1 purinergic) receptors. By binding to A1 receptors in the sinoatrial and, especially, the atrioventricular (AV) node, Adenosine activates potassium channels and inhibits calcium influx, which slows conduction through the AV node and can transiently block it altogether; this interrupts the reentrant electrical circuit responsible for most paroxysmal supraventricular tachycardia and allows the heart's normal sinus rhythm to resume. Separately, by acting on A2A receptors on coronary vascular smooth muscle, Adenosine produces potent coronary vasodilation; because diseased (stenotic) coronary arteries dilate less than normal arteries, this creates a relative difference in blood flow between normal and diseased vessels that can be detected on myocardial perfusion imaging during pharmacologic stress testing.

C

Adecard is guideline-supported, per Pediatric Advanced Life Support (PALS) guidance, for the emergencytermination of paroxysmal supraventricular tachycardia (PSVT) in infants and children, using weight-based dosing: an initial rapid IV orintraosseous bolus of 0.1 mg/kg (maximum first dose 6 mg), followed if needed by a second dose of 0.2 mg/kg (maximum second dose 12 mg), eachgiven as a fast push immediately followed by a saline flush, in a monitored setting with resuscitation equipment available. The safety andefficacy of Adecard as a pharmacologic cardiac stress agent have not been established in children, and this use is generally reserved foradults.