RESUMEN
OBJECTIVE: The aim was to study the pharmacodynamic interactions and safety of the co-administration of the calcium sensitizer levosimendan and the calcium antagonist felodipine in patients with coronary heart disease (CHD) and with normal ejection fraction (EF). METHODS: The study was a randomized, double blind, placebo-controlled, crossover study in 24 male patients with Canadian Cardiovascular Society (CCS) class II CHD, consisting of four treatment periods, each period lasting for 7-10 days. In the first period the patients received either oral levosimendan (LS) (0.5 mg) or placebo (PL) four times daily and were then crossed over to the other therapy for the second and third period. After the third period the patients were changed back to the therapy administered in the first period. Open label felodipine (FD), 5 mg once daily, was co-administered on the third and fourth treatment period. Differences between the four treatments (LS, PL, FD and LS + FD) in systolic time intervals, exercise capacity, heart rate, blood pressure and 24-hour continuous electrocardiography (Holter) were assessed. RESULTS: The differences between treatments regarding heart rate corrected electromechanical systole (QS2i), pre-ejection period (PEP) and heart rate corrected left ventricular ejection time (LVETi) were significant (p < 0.001, p < 0.001 and p = 0.004, respectively). Levosimendan shortened QS2i by 10 ms (95% CI [-15, -4]), PEP by 6 ms (95% CI [-10, -3]) and LVETi by 7 ms (95% CI [-13, -2]) compared with placebo, indicating a moderate positive inotropic effect. The results were similar, when levosimendan was administered concomitantly with felodipine. Levosimendan did not significantly change systolic blood pressure and no potentiation of response was seen with concomitant administration with felodipine. The increase in heart rate after levosimendan and its combination with felodipine was equal (6-7 bpm). There was no difference in mean cumulative exercise time between the treatments. The combination of levosimendan and felodipine was well tolerated. CONCLUSION: No clinically significant pharmacodynamic interactions between levosimendan and felodipine were seen. Levosimendan did not aggravate myocardial ischemia. Levosimendan can safely be administered to patients with CHD together with a dihydropyridine calcium antagonist.