Purpose: The aim was to prepare and evaluate unitary doses of propafenone (UDP) used in children with supraventricular tachycardia.
Methods: UDP were prepared from four brands of tablets at doses of propafenone, 11, 25 and 90 mg, used in the Cardiology Service of this Institute. The stability of doses was determined at 20±5°C and 40°C for up to day 30. Besides, a weight variation test was performed. Plasma levels of propafenone were determined at steady state in 3 children diagnosed with supraventricular tachycardia under treatment with UDP. Concentrations of drug in blood were measured using a high pressure liquid chromatography method, previously validated.
Results: The stability of UDP, showed no significant statistical differences (p > 0.05) between doses or brands up to day 30, at both temperatures. The coefficient of variation from the weight variation was less than 6%. The plasma levels of propafenone at steady state were: patient 1, 31.57 ng/ml; patient 2, 226.46 ng/ml; and patient 3, 221.29 ng/ml.
Conclusions: The actual administered dose for the patients could vary up to 6%, and doses prepared from different brands of tablets remain stables for up to day 30 at both temperatures. UDP is a temporal, safe and alternative option when pediatrics formulation of this drug is lacking.