The anti-influenza drug oseltamivir reduces atrial fibrillation in an experimental whole-heart model

Influenza associated cardiac arrhythmia- a systematic review

BACKGROUND

Influenza infection is rarely associated with cardiac conduction disorder. Cardiac arrhythmias due to such an infection have a full spectrum with ventricular arrythmias being the most common.

METHODS

In our systematic review from PubMed, OVID Medline and EMBASE we have identified 23 articles describing arrythmias associated with different influenza infection. Most of them were case reports where ventricular arrhythmias were the most common.

RESULTS

Complete heart block after influenza infection is usually temporary and a permanent pacemaker is rarely needed. There are reports of Influenza associated with arrhythmias in adults, neonates, and even fetuses in pregnant woman. Different mechanisms were described in literatures by which influenza causes arrhythmias such as interleukin 6 & tumor necrosis factor-alpha mediated inflammatory response, sympathetic overactivation, focal myocarditis and cleavage of angiotensin converting enzyme 2 protein which is cardioprotective.

CONCLUSIONS

ACE 2 binder influenza viruses have more prone to be associated with cardiac conduction disorder. Oseltamivir for influenza infection is also associated with bradycardia and can shorten or lengthen QT segment. Influenza vaccination has found to be protective from cardiac arrhythmia.

Simultaneous analyses of hemodynamic and electrophysiological effects of oseltamivir along with its pharmacokinetic profile using the canine paroxysmal atrial fibrillation model

Since information of antiviral drug oseltamivir on the anti-atrial fibrillation (AF) property is still limited, we assessed it using the canine paroxysmal AF model. Oseltamivir in doses of 3 and 30 mg/kg/10 min was intravenously infused to the isoflurane-anesthetized, chronic atrioventricular block dogs (n = 6) with monitoring hemodynamic and electrophysiological variables, in which AF was induced by 10 s of burst pacing on atrial septum. Oseltamivir decreased AF incidence and AF duration, and prolonged AF cycle length in a dose-dependent manner. The low and high doses attained the peak plasma drug concentrations of 9.7 and 96.5 μg/mL, which were approximately 100 and 1000 times greater than those observed in human clinical cases, respectively. The low dose of oseltamivir decreased mean blood pressure without altering sinoatrial or idioventricular rate, whereas its high dose reduced each of them. Oseltamivir delayed inter-atrial conduction in dose- and frequency-dependent manners, whereas it prolonged atrial effective refractory period in dose-dependent but frequency-independent manners. The high dose prolonged ventricular effective refractory period, which was not detected with the low dose. These findings can be used for repurposing oseltamivir as an anti-AF drug candidate.

Translational Studies on Anti-Atrial Fibrillatory Action of Oseltamivir by its in vivo and in vitro Electropharmacological Analyses

Oseltamivir has been shown to prolong the atrial conduction time and effective refractory period, and to suppress the onset of burst pacing-induced atrial fibrillation in vitro. To better predict its potential clinical benefit as an anti-atrial fibrillatory drug, we performed translational studies by assessing in vivo anti-atrial fibrillatory effect along with in vivo and in vitro electropharmacological analyses. Oseltamivir in intravenous doses of 3 (n = 6) and 30 mg/kg (n = 7) was administered in conscious state to the persistent atrial fibrillation model dogs to confirm its anti-atrial fibrillatory action. The model was prepared by tachypacing to the atria of chronic atrioventricular block dogs for > 6 weeks. Next, oseltamivir in doses of 0.3, 3 and 30 mg/kg was intravenously administered to the halothane-anesthetized intact dogs to analyze its in vivo electrophysiological actions (n = 4). Finally, its in vitro effects of 10–1,000 μM on I_K,ACh, I_Kur, I_Kr, I_Na and I_CaL were analyzed by using cell lines stably expressing Kir3.1/3.4, K_V1.5, hERG, Na_V1.5 or Ca_V1.2, respectively (n = 3 for I_K,ACh and I_Kr or n = 6 for I_Kr, I_Na and I_CaL). Oseltamivir in doses of 3 and 30 mg/kg terminated the atrial fibrillation in 1 out of 6 and in 6 out of 7 atrial fibrillation model dogs, respectively without inducing any lethal ventricular arrhythmia. Its 3 and 30 mg/kg delayed inter-atrial conduction in a frequency-dependent manner, whereas they prolonged atrial effective refractory period in a reverse frequency-dependent manner in the intact dogs. The current assay indicated that IC₅₀ values for I_K,ACh and I_Kr were 160 and 231 μM, respectively, but 1,000 µM inhibited I_Na, I_CaL and I_Kur by 22, 19 and 13%, respectively. The extent of I_Na blockade was enhanced at faster beating rate and more depolarized resting membrane potential. Oseltamivir effectively terminated the persistent atrial fibrillation, which may be largely due to the prolongation of the atrial effective refractory period and inter-atrial conduction time induced by I_K,ACh and I_Kr inhibitions along with I_Na suppression. Thus, oseltamivir can exert a powerful anti-atrial fibrillatory action through its ideal multi-channel blocking property; and oseltamivir would become a promising seed compound for developing efficacious and safe anti-atrial fibrillatory drugs.

Effect of triple antimicrobial therapy on electrocardiography parameters in patients with mild-to-moderate coronavirus disease 2019

OBJECTIVE

The effects of treatment of coronavirus disease 2019 (COVID-19) with a triple combination composed of hydroxychloroquine, an an-tiviral, and an antibiotic on electrocardiography (ECG) parameters in patients with mild-to-moderate symptoms are not wholly understood. We aimed to explore the changes in ECG parameters after treatment with triple combination therapy in patients with mild-to-moderate symptomatic COVID-19.

METHODS

This retrospective, single-center case series analyzed 91 patients with mild-to-moderate symptomatic COVID-19 at Ankara Gazi Mus-tafa Kemal State Hospital of Ankara City, Turkey, from April 1, 2020, to April 30, 2020. Forty-three patients were treated with hydroxychloroquine+oseltamivir+azithromycin (Group 1) and 48 patients were treated with hydroxychloroquine+oseltamivir+levofloxacin (Group 2). Heart rate, P wave duration, P wave dispersion, PR interval, QRS duration, corrected QT interval (QTc), QTc dispersion (QTD), delta QTc, Tp-e, Tp-e dispersion, and Tp-e/QTc ratio were all calculated from the baseline and posttreatment 12-lead ECG recordings.

RESULTS

The QTc, QRS duration, Tp-e, PR interval, and P wave duration were significantly increased after treatment (p<0.001; p<0.001; p<0.001; p=0.001; p=0.001). The posttreatment C-reactive protein level was significantly lower than at baseline in Group 1 (p=0.014). At admission, 30% of patients had QT prolongation, and 4.3% of them had a QT duration >500 ms. Both Group 1 and Group 2 showed significant prolongation of the QTc interval (Group 1; p<0.001 vs. Group 2; p<0.001), QRS duration (Group 1; p=0.006 vs. Group 2; p=0.014), Tp-e (Group 1; p=0.036 vs. Group 2; p<0.001), and PR interval (Group 1; p=0.002 vs. Group2; p=0.05). The QTD was significantly decreased in Group 1 (p<0.001). None of the patients experienced any overt ventricular arrhythmia.

CONCLUSION

To the best of our knowledge, this study is the first to investigate QT prolongation in a population of COVID-19 patients treated with triple combination therapy. We found that there was a significant decrease in the QTD after the treatment in patients who were taking triple therapy including azithromycin.

Oseltamivir-Associated Bradycardia in Critically Ill Patients

BACKGROUND

Oseltamivir is frequently administered to critically ill patients with presumed influenza. It may modulate Na⁺, K⁺, and Ca²⁺ channels to produce bradycardia.

OBJECTIVE

To evaluate the association between oseltamivir and bradycardia in critically ill patients and assess parameters associated with bradycardia.

METHODS

This was a retrospective audit of 203 critically ill adults with presumed influenza receiving at least 2 doses of oseltamivir. The primary outcome was the occurrence of bradycardia, defined as a heart rate (HR) ≤59 beats per minute (BPM) while receiving oseltamivir or a decrease of ≥20 BPM compared with the lowest HR before initiating oseltamivir.

RESULTS

A total of 88 (43.4%) patients manifested bradycardia, 59 with HR ≤59 BPM, 19 with HR decrease of ≥20 BPM, and 10 with both. The time from first dose to bradycardia was 51.4 ± 43 hours. In all, 48 (54.6%) patients received therapies for bradycardia, including increased inotropic/vasopressor dose, electrolyte replacement, electrocardiogram, discontinuation of other medications, cardiology consult, discontinuation of oseltamivir, and pacer placement. There were no significant differences between groups with bradycardia versus without in terms of demographics, laboratory values, hospital characteristics, or oseltamivir dosing. Multivariate logistic regression showed that bradycardia was associated with baseline HR, age, past medical history of neurological issues, and positive influenza status. Between hours 6 through 126, significant differences existed between groups in actual and lowest HR.

CONCLUSION AND RELEVANCE

Oseltamivir was associated with clinically relevant bradycardia in critically ill patients. Clinicians should closely monitor HR in critically ill patients receiving oseltamivir.

Antiarrhythmic Effect of Ranolazine in Combination with Selective NCX-Inhibition in an Experimental Model of Atrial Fibrillation

The aim of this study was to investigate the effects of a combination of ranolazine with different selective inhibitors of the Na⁺/Ca²⁺-exchanger (NCX) in an established experimental model of atrial fibrillation (AF). Eighteen hearts of New Zealand white rabbits were retrogradely perfused. Atrial catheters were used to record monophasic action potentials (aPRR). Hearts were paced at three different cycle lengths. Thereby, atrial action potential durations (aAPD₉₀), atrial effective refractory periods (aERP) and atrial post-repolarization refractoriness were obtained. Isoproterenol and acetylcholine were employed to increase the occurrence of AF. Thereafter, the hearts were assigned to two groups (n = 9 each group) and additionally perfused with a combination of 10 µM ranolazine and 1 µM of the selective NCX-inhibitor ORM-10103 (group A: Rano-ORM) or 10 µM ranolazine and 1 µM of another NCX-inhibitor, SEA0400 (group B: Rano-SEA). The infusion of Iso/ACh led to a shortening of aAPD₉₀, aERP, aPRR and the occurrence of AF episodes was significantly increased. Additional perfusion with ranolazine and ORM-10103 (group A) significantly prolonged the refractory periods and aPRR and AF episodes were effectively reduced. In group B, Rano-SEA led to a slight decrease in aAPD₉₀ while aERP and aPRR were prolonged. The occurrence of AF episodes was consecutively reduced. To our knowledge, this is the first study investigating the effect of ranolazine combined with different selective NCX-inhibitors in an isolated whole-heart model of AF. Both combinations prolonged aERP and aPRR and thereby suppressed the induction of AF.

COVID-19 Pandemic and Cardiovascular Disease

There seems to be a unique interplay between 2019 novel coronavirus (SARS-CoV-2) and cardiovascular diseases, although it is predominantly a respiratory illness. Patients with pre-existing cardiovascular co-morbidities appear to be at highest risk for mortality from coronavirus disease 2019 (COVID-19) along with the elderly; COVID-19 also contributes to cardiovascular complications, including acute coronary syndromes, arrhythmias, myocarditis, acute heart failure, and, in the most severe cases, cardiogenic shock and death. Several medications proposed in the treatment of COVID-19 require cardiac monitoring owing to their cardiac-specific adverse effects. Ultimately, the COVID-19 pandemic has jeopardized the safety of heart transplantation and has placed transplant recipients on immunosuppressive therapies at significant risk. In this article, the authors summarize the rapidly emerging data on the cardiovascular implications of SARS-CoV-2 and COVID-19.

Electropharmacological Characterization of Aciclovir in the Halothane-Anesthetized Dogs: A Proposal of Evaluation Method for Cardiovascular Safety Pharmacology of Anti-virus Drugs

Given limited information regarding the pathophysiology underlying aciclovir-associated, clinically observed cardiovascular adverse events including chest pain, tachycardia, bradycardia, palpitation, arrhythmia, hypertension and hypotension, we investigated its electropharmacological effects using the halothane-anesthetized beagle dogs. Aciclovir in doses of 2 and 20 mg/kg was sequentially infused over 10 min with an interval of 20 min (n = 4), which would achieve sub-therapeutic to supra-therapeutic levels of plasma concentrations. Aciclovir decreased the total peripheral vascular resistance along with the blood pressure in a dose-related manner, which increased the heart rate, ventricular contraction and atrioventricular nodal conduction speed probably via a reflex-mediated increase of sympathetic tone. No significant change was detected in the intra-atrial or intra-ventricular conduction, indicating that aciclovir may not inhibit atrial or ventricular I_Na. Aciclovir prolonged the repolarization period in a dose-related as well as in a reverse frequency-dependent manners, indicating that aciclovir may inhibit I_Kr, which was supported by the T_peak - T_end prolongation. Aciclovir transiently prolonged the J - T_peakc possibly through a reflex-mediated increase of sympathetic tone, indicating an increase of net inward current in the early repolarization phase. Thus, aciclovir may directly inhibit I_Kr, and also have the potential to indirectly induce Ca²⁺ overload leading to early afterdepolarization. These in vivo electropharmacological profile of aciclovir would partly explain the onset mechanism of clinical adverse events.