Dosage ; See below.
| Mode Of Action | Slowing conduction through AV node and interrupts AV reentry pathways e.g. adenosine. |
|---|---|
| Drug Indication | Rapid reversion to sinus rhythm of paroxysmal supraventricular tachycardias, including those associated with accessory conducting pathways (e.g. Wolff-Parkinson-White syndrome); aid to diagnosis of broad or narrow complex supraventricular tachycardias. |
| Precautions | Monitor ECG and have resuscitation facilities available; atrial fibrillation or flutter with accessory pathway (conduction down anomalous pathway may increase); first-degree AV block; bundle branch block; left main coronary artery stenosis; uncorrected hypovolaemia; stenotic valvular heart disease; left to right shunt; pericarditis; pericardial effusion; autonomic dysfunction; stenotic carotid artery disease with cerebrovascular insufficiency; recent myocardial infarction; heart failure; heart transplant. |
| Contra-Indications | Second- or third-degree AV block and sick sinus syndrome (unless pacemaker fitted); long QT syndrome; severe hypotension; decompensated heart failure; chronic obstructive lung disease (including asthma). |
| Side Effects | Nausea; arrhythmia (discontinue if asystole or severe bradycardia occur), sinus pause, AV block, flushing, angina (discontinue), dizziness; dyspnoea; headache; less commonly metallic taste; palpitation, hyperventilation, weakness, blurred vision, sweating; very rarely transient worsening of intracranial hypertension, bronchospasm, injection-site reactions; also reported vomiting, syncope, hypotension (discontinue if severe), cardiac arrest, respiratory failure (discontinue), and convulsions. |
| Dosage | By rapid intravenous injection into central or large peripheral vein, 6 mg over 2 seconds with cardiac monitoring; if necessary followed by 12 mg after 1-2 minutes, and then by 12 mg after a further 1-2 minutes; increments should not be given if high level AV block develops at any particular dose. Important: Patients with a heart transplant are very sensitive to effects of adenosine and should receive initial dose of 3 mg over 2 seconds, followed if necessary by 6 mg after 1-2 minutes, and then by 12 mg after a further 1-2 minutes. Also, if essential to give with dipyridamole reduce adenosine dose to a quarter of the usual dose. |
| Special Information | Treatment of choice for terminating paroxysmal supraventricular tachycardia. |
| Pregnancy Category | Category C |
| Pregnancy Category Description | Drugs which, owing to their pharmacological effects, or may be suspected of causing detrimental effects on human foetus or neonates without causing malfunctions. These effects may be reversible |
| Drug Category | DRUGS ACTI NG ON THE CARDIO-VASCULAR SYSTEM |
| Drug Sub-Category | Anti-arrhythmic drugs |