Propafenone (CAS 34183-22-7) is an effective antiarrhythmic drug used in children,
although in some countries no specific pediatric formulation is available. The aim
of this study is to compare the relative bioavailability of a magistral (MAG) preparation
of propafenone versus its commercial (COM) presentation in a group of 16 Mexican healthy
volunteers. Bioavailability was determined after crossover administration of the drugs,
through a randomized two-phase trial. All volunteers had normal hepatic and renal
functions, determined clinically at the beginning of the study, and received 150 mg
of either COM (tablets) or MAG (suspension). Blood samples were drawn for a 24-h post-dose
analysis by HPLC to measure plasma levels of propafenone. Subjects (mean 25.9 ± 5.3
years and 66.1 ± 12.4 kg) had the following pharmacokinetic parameters: Cmax 189.9 ± 20.92 ng/mL, Tmax 1.5 h, AUC 322.4 ± 36.28 ng • ml1 • h for COM. Values for MAG were Cmax 225.8 ± 24.38 ng/mL, Tmax 1.7 h and AUC 359.3 ± 27.90 ng • ml1 • h. These values yielded a relative bioavailability of 111.42 % for MAG compared
with COM. No electrocardiographic changes were recorded in any subject with respect
to the baseline value, in both treatment schemes. Therefore, propafenone suspension
prepared as a magistral formulation may be used as an alternative drug in pediatric
patients.
Key words
Antiarrhythmics - CAS 34183-22-7 - Propafenone, bioavailability, healthy volunteers,
hospital pharmacy, pharmacokinetics
