Safety and efficacy of procainamide infusions

Area of Science:

• Cardiology
• Clinical Pharmacology

Background:

• Lidocaine resistance necessitates alternative antiarrhythmic therapies.
• Procainamide is a potential alternative for managing refractory ventricular arrhythmias.

Purpose of the Study:

• To evaluate the efficacy and tolerability of intravenous procainamide using a novel two-infusion technique in patients resistant to lidocaine.
• To determine the pharmacokinetic profile and factors influencing procainamide serum concentrations.

Main Methods:

• Thirty-four patients received procainamide via a two-infusion strategy.
• Pharmacokinetic parameters, including peak and steady-state serum concentrations, were monitored.
• Factors such as dose, renal function, heart failure, and acetylator status were assessed for their influence on drug levels.

Main Results:

• A mean peak serum concentration of 7.1 mg/L and steady-state concentration of 6.5 mg/L were achieved.
• Ventricular arrhythmias were abolished in 74% of patients at a mean steady-state level of 6.9 mg/L.
• Moderate decreases in blood pressure and heart rate were observed; one patient experienced hypotension.

Conclusions:

• The two-infusion procainamide method is effective in treating refractory ventricular arrhythmias.
• Procainamide is generally well-tolerated, with dose, renal impairment, heart failure, and acetylator status impacting its pharmacokinetics.
• This technique offers a viable therapeutic option for patients unresponsive to conventional lidocaine therapy.