Sustained release procainamide in patients with myocardial infarction

Area of Science:

• Cardiology
• Pharmacology
• Clinical Medicine

Background:

• Ventricular arrhythmias are a common complication following acute myocardial infarction.
• Maintaining therapeutic procainamide plasma concentrations is crucial for managing these arrhythmias.
• Conventional oral procainamide formulations often struggle to achieve consistent therapeutic levels.

Purpose of the Study:

• To compare the efficacy of sustained release procainamide tablets versus conventional capsules in achieving therapeutic blood levels in patients post-myocardial infarction.
• To evaluate the optimal dosing regimen for sustained release procainamide in this patient population.

Main Methods:

• A study involving 34 patients receiving sustained release procainamide tablets 48 hours after acute myocardial infarction.
• A comparative group of 21 patients received conventional procainamide capsules.
• Plasma concentrations were monitored to assess therapeutic range achievement (4-8 mug/ml).

Main Results:

• Sustained release procainamide consistently achieved therapeutic blood levels (4-8 mug/ml) with an 8-hourly 1.5g maintenance dose after a 2g loading dose.
• Conventional procainamide capsules failed to reach or maintain therapeutic plasma concentrations despite a 3-hourly 375mg maintenance dose after a 1g loading dose.

Conclusions:

• Sustained release procainamide tablets are more effective than conventional capsules in achieving and maintaining therapeutic plasma concentrations in patients recovering from myocardial infarction.
• The use of sustained release formulations is recommended for oral procainamide therapy in managing ventricular arrhythmias post-myocardial infarction.