Key result
Dexchlorpheniramine decreased the cardiac force of contraction with an IC50 of 4.12 μmol/L and significantly prolonged RR, QRS, and QT intervals at concentrations higher than therapeutic levels.
Why the study?
Does dexchlorpheniramine alter the contractile and electrical activities in isolated rat hearts?
Does dexchlorpheniramine alter the contractile and electrical activities in isolated rat hearts?
Dexchlorpheniramine exerts direct concentration-dependent contractile depression and electrical alterations (prolonged QRS, RR, QT, and arrhythmias) in isolated rat hearts at supratherapeutic concentrations.
Answers are grounded in this paper and cite their sources.
Dexchlorpheniramine depresses rat heart contractility at high doses; leaves open human relevance, no practice change.
Dexchlorpheniramine is a first-generation H1-Antihistamine, and despite numerous studies on the cardiotoxicity of other first-generation H1-Antihistamines, the effects of dexchlorpheniramine on cardiac physiology are not well known. The objective of the present study was to characterize the action of dexchlorpheniramine on the amplitude of the force of contraction, and on the electrocardiographic parameters in isolated and perfused hearts of Wistar rats. The Langendorff isolated perfused heart technique was performed and the effects of dexchlorpheniramine (3-300mol/L, n=6) on the cardiac contraction and on the RR, QRS, QT and QTc parameters of the electrocardiogram were measured. The RR, QRS, and QT intervals increased by dexchlorpheniramine, not being so with the QTc interval. This probably suggests some type of action of dexchlorpheniramine on cardiac K+ and Na+ channels. The amplitude of the cardiac force of contraction decreased in concentration dependent manner, which suggests some effect on the Ca2+ current by dexchlorpheniramine. The IC50 estimated for the inhibition of the cardiac force of contraction was 4.121.64mol/L.
No takes yet. Share an insight, caveat, or question.
Martínez et al. (2018) studied Healthy (animal model) (n=6). Dexchlorpheniramine vs. Control (baseline) was evaluated on Inhibition of cardiac force of contraction (IC50 4.12 μmol/L). Dexchlorpheniramine decreased the cardiac force of contraction with an IC50 of 4.12 μmol/L and significantly prolonged RR, QRS, and QT intervals at concentrations higher than therapeutic levels.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: