Abstract
Flecainide acetate is an antiarrhythmic agent of class Ic of Vaughan-Williams' classification. It has already been introduced for clinical use in numerous countries ; the oral preparation was launched in Japan in 1991.
In the present phase I study, flecainide acetate injection was administered to healthy adults at doses of 0.5 to 2.0 mg/kg to evaluate its safety, pharmacokinetic behavior and pharmacological action.
Throughout the study period no subjective symptoms were experienced by any subject except for mild transient numbness of the tongue in 3 patients in the 1.0 or 2.0 mg/kg groups. There were no abnormal laboratory test results.
Plasma concentration of flecainide showed a biphasic pattern of elimination ; the elimination half-life in the λα phase was 2 to 3 min and that in the λβ phase was about 10 hours. Considering that these findings were relatively consistent with reported results from Western investigators, it appears that the pharmacokinetic behavior of flecainide does not differ from race to race. The P-R and QRS intervals were not clearly correlated with dose, but both intervals were prolonged after the administration of flecainide. The present study provides suggestive evidence that flecainide presents no safety problem if it is used in the dose range indicated above.
The present study provides suggestive evidence that flecainide presents no safety problem if it is used in the dose range indicated above.
