During the last decades, the introduction of new, more efficient drugs, has significantly improved the heart failure (HF) therapy of adults. Therapeutic focus has shifted from simple hemodynamic manipulation to include neurohumoral modulation as a consequence of the better understanding of mechanisms of HF formation, in particular at the cellular level. The aetiologies of HF in children are remarkably different and more varied than in the adult population. Cardiac failure is usually caused by congenital heart disease and cardiomyopathy in children, whereas in adults, coronary artery disease, hypertension and myocardial infarction are the most common causes. Despite this fact, pharmacotherapy of children is based on the same drugs, usually extrapolated from adult HF regimens. A recently published study in children treated with the drugs known to be efficient in adult HF therapy, provides encouragement that the outcomes might be similarly beneficial. On the other hand, some reports outline that children with HF, especially patients with systemic right ventricles or single ventricle physiology, require specific drug guidelines. A general characteristic of HF pharmacotherapy in children is the lack of paediatrically designed drugs. Drugs currently used in the treatment of HF in paediatric patients are designed for adults, and their efficacy, safety and quality have generally not been confirmed by clinical studies of children. Aside from this, availability of commercial paediatric drug formulations labelled for treatment of HF in children significantly influences the quality and efficacy of therapy.

Ibogaine is an indole alkaloid originally extracted from the root bark of the African rainforest shrub Tabernanthe iboga. It has been explored as a treatment for substance abuse because it interrupts drug addiction and relieves withdrawal symptoms. However, it has been shown that ibogaine treatment leads to a sharp and transient fall in cellular ATP level followed by an increase of cellular respiration and ROS production. Since contractile tissues are sensitive to changes in the levels of ATP and ROS, here we investigated an ibogaine-mediated link between altered redox homeostasis and uterine contractile activity. We found that low concentrations of ibogaine stimulated contractile activity in spontaneously active uteri, but incremental increase of doses inhibited it. Inhibitory concentrations of ibogaine led to decreased SOD1 and elevated GSH-Px activity, but doses that completely inhibited contractions increased CAT activity. Western blot analyses showed that changes in enzyme activities were not due to elevated enzyme protein concentrations but posttranslational modifications. Changes in antioxidant enzyme activities point to a vast concentration-dependent increase in H2O2 level. Knowing that extracellular ATP stimulates isolated uterus contractility, while H2O2 has an inhibitory effect, this concentration-dependent stimulation/inhibition could be linked to ibogaine-related alterations in ATP level and redox homeostasis.

Ibogaine, administered as a single oral dose (1-25 mg/kg body weight), has been used as an addiction-interrupting agent. Its effects persist for up to 72 h. Ex vivo results showed that ibogaine induced cellular energy consumption and restitution, followed by increased reactive oxygen species production and antioxidant activity. Therefore, the aim of this work was to explore the effect of a single oral dose of ibogaine (1 or 20 mg/kg body weight) on antioxidative defenses in rat liver and erythrocytes. Six and 24 h after ibogaine administration, histological examination showed glycogenolytic activity in hepatocytes, which was highest after 24 h in animals that received 20 mg/kg ibogaine. There were no changes in the activities of superoxide dismutases, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase in the liver and erythrocytes after ibogaine treatment, regardless of the dose. Hepatic xanthine oxidase activity was elevated in rats that received 20 mg/kg compared to the controls (p<0.01), suggesting faster adenosine turnover. TBARS concentration was elevated in the group treated with 1 mg/kg after 24 h compared to the controls (p<0.01), suggesting mild oxidative stress. Our results show that ibogaine treatment influenced hepatic redox homeostasis, but not sufficiently to remodel antioxidant enzyme activities at 6 and 24 h post-ibogaine application.

Historically, quinidine was the first medicine used in the therapy of heart arrhythmias. Studies in the early 20th century identified quinidine, a diastereomer of the antimalarial quinine, as the most potent of the antiarrhythmic substances extracted from the cinchona plant. Quinidine is used by the 1920s, as an antiarrhythmic agent to maintain sinus rhythm after the conversion from atrial flutter or atrial fibrillation and to prevent recurrence of ventricular tachycardia or ventricular fibrillation. Its value in chronic prophylaxis of relapse of ventricular arrhythmia was brought under suspicion after publishing of meta analysis that showed that the application of quinidine increases mortality. Due to numerous proofs of increased risk for the appearance of ventricular arrhythmia and sudden death, as well as a number of other adverse effects and drug interactions, quinidine was withdrawn from use and in the recent years has become unavailable in many countries. On the other hand, recent studies have demonstrated that quinidine is the only oral medication that has consistently shown efficacy in preventing arrhythmias and terminating storms due to recurrent ventricular fibrillation, in patients with Brugada syndrome, idiopathic ventricular fibrillation and early repolarization syndrome. Quinidine is also the only antiarrhythmic drug that normalized the QT interval in patients with the congenital short QT syndrome. The aim of this review is to provide good insight into pro and contra arguments for quinidine use in ventricular arrhythmias evidence based on recently published literature.

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