Effect of Maxilatine on Blood Pressure
Maxilatine (mexiletine) has minimal to no clinically significant effect on blood pressure in most patients. 1
Hemodynamic Profile
Mexiletine produces small, usually not statistically significant decreases in cardiac output and increases in systemic vascular resistance, but blood pressure and pulse rate remain essentially unchanged. 1
- Hemodynamic studies in patients with normal or abnormal myocardial function following oral mexiletine administration showed no significant negative inotropic effect 1
- Mild depression of myocardial function, similar to that produced by lidocaine, has occasionally been observed following intravenous mexiletine therapy in patients with cardiac disease 1
Mechanism and Electrophysiologic Effects
Mexiletine is a Class 1B antiarrhythmic agent structurally similar to lidocaine that works by inhibiting the inward sodium current, reducing the rate of rise of the action potential. 1
- In patients with normal conduction systems, mexiletine has minimal effect on cardiac impulse generation and propagation 1
- The drug does not prolong ventricular depolarization (QRS duration) or repolarization (QT intervals) as measured by electrocardiography 1
- In clinical trials, no development of second-degree or third-degree AV block was observed 1
Clinical Implications for Hypertensive Patients
Mexiletine can be used in hypertensive patients without concern for significant blood pressure elevation or reduction. 1
- Unlike many other antiarrhythmic agents, mexiletine is not listed among drugs that alter blood pressure in major hypertension guidelines 2
- The drug's neutral effect on blood pressure makes it suitable for patients with concurrent hypertension requiring antiarrhythmic therapy 1
Important Caveats
In patients with preexisting conduction defects, mexiletine may occasionally cause depression of sinus rate, prolongation of sinus node recovery time, and changes in intraventricular conduction. 1