potential cardiovascular toxic effects of astemizole and its interaction with amiodarone in rats

ABSTRACT

This study dealt with the possible cardiovascular toxic effects of non-sedating antithistamine [astemizole] and assess the potential arrythmic effect of amiodarone [antiarrythmic agent] when used concomitantly with astemizole. The experiments were performed on adult albino rats and astemizole was injected intraperitoneally in geometrical cumulative doses of 0.005, 0.05, 0.5, 5 and 50 mg/kg. Five cardiovascular parameters were recorded [systolic and diastolic blood pressure, heart rate, RR and corrected QT [QTc] intervals]. The results revealed that astemizole produced a significant decrease in the blood pressure and heart rate in a doses more than the effective therapeutic dose [ED50] in rats, doses below the ED50 did not produce significant changes. Meanwhile, astemizole produced a significant prolongation of the RR and corrected QT [QTc] intervals with doses less than the effective therapeutic dose in rats. Amiodarone injected intravenously [5 mg/kg] 30 minutes before astemizole produced a significant potentiation of the effects of astemizole on all the above forementioned cardiovascular parameters