Drug General Information (ID: DDIYMIP1ST)
Drug Name			Dofetilide		Drug Info		Terbutaline		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiarrhythmic Agents				Bronchodilators
Structure

Mechanism of Dofetilide-Terbutaline Interaction (Severity Level: Major)
Increased risk of prolong QT interval Click to Show/Hide Mechanism Graph
Drug Name		Dofetilide				Terbutaline
Mechanism 1		Prolong QT interval				Prolong QT interval
Key Mechanism Factor 1
		Factor Name		QT interval
		Factor Description		Long QT syndrome is a heart signaling disorder that can cause a fast, chaotic heartbeat (arrhythmia). Many people may not exhibit symptoms, and usually the condition is detected during routine medical tests. In others, the most common symptoms include: sudden fainting, palpitations, dizziness, seizures, sudden death.
Mechanism Description		Increased risk of prolong QT interval by the combination of Dofetilide and Terbutaline
Increased risk of ventricular arrhythmias Click to Show/Hide Mechanism Graph
Drug Name		Dofetilide				Terbutaline
Mechanism 2		Prolong QT interval				Hypokalemia
Key Mechanism Factor 2
		Factor Name		Ventricular arrhythmias
		Factor Description		Ventricular arrhythmias are abnormal heart rhythms that cause your heart's lower chambers to pump blood instead of pumping it. This can limit or stop your heart from supplying blood to your body. While some of these arrhythmias are harmless and do not cause symptoms, others can have serious, even fatal, effects on your body.
Mechanism Description		Increased risk of ventricular arrhythmias by the combination of Dofetilide and Terbutaline

Recommended Action
Management		Caution is advised if beta-2 adrenergic agonists are used in combination with other drugs that prolong the QT interval, including class IA and III antiarrhythmic agents, certain neuroleptic agents, phenothiazines, tricyclic antidepressants, quinolones, ketolide and macrolide antibiotics, and cisapride. It may be appropriate to monitor ECG and serum electrolytes during chronic systemic use or high-dose therapy. Patients should be advised to seek medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitations, irregular heartbeat, shortness of breath, or syncope.

References
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