Amiodarone: Development, Clinical Indications, and Safety

Amiodarone for the Treatment of Arrhythmias in COVID-19 Patients Does Not Increase the Risk of Pulmonary Fibrosis: A Retrospective Cohort Study

Amiodarone is a class III antiarrhythmic medication used to treat atrial and ventricular tachyarrhythmias. Pulmonary fibrosis from amiodarone use is a well-documented side effect. Pre-COVID-19 pandemic studies have shown that amiodarone-induced pulmonary fibrosis occurs in 1%-5% of patients and usually occurs between 12 to 60 months after initiation. The risk factors associated with amiodarone-induced pulmonary fibrosis include a high total cumulative dose (treatment longer than two months) and high maintenance dose (>400 mg/day). COVID-19 infection is also a known risk factor for developing pulmonary fibrosis and occurs in approximately 2%-6% of patients after a moderate illness. This study aims to assess the incidence of amiodarone in COVID-19 pulmonary fibrosis (ACPF). This is a retrospective cohort study with 420 patients with COVID-19 diagnoses between March 2020 and March 2022, comparing two populations, COVID-19 patients with exposure to amiodarone (N=210) and COVID-19 patients without amiodarone exposure (N=210). In our study, pulmonary fibrosis occurred in 12.9% of patients in the amiodarone exposure group compared to 10.5% of patients in the COVID-19 control group (p=0.543). In multivariate logistic analysis, which controlled for clinical covariates, amiodarone use in COVID-19 patients did not increase the odds of developing pulmonary fibrosis (odds ratio (OR): 1.02, 95% confidence interval (CI): 0.52-2.00). The clinical factors associated with the development of pulmonary fibrosis in both groups included a history of preexisting interstitial lung disease (ILD) (p=0.001), exposure to prior radiation therapy (p=0.021), and higher severity of COVID-19 illness (p<0.001). In conclusion, our study found no evidence that amiodarone use in COVID-19 patients increased the odds of developing pulmonary fibrosis at six-month follow-up. However, long-term amiodarone usage in the COVID-19 population should be based on the physician's discretion.

Emerging role of amiodarone and dronedarone, as antiarrhythmic drugs, in treatment of leishmaniasis

Leishmaniasis is a group of human and animal diseases causing 20,000-40,000 annual deaths and its etiological agents belong to the Leishmania genus. The most current treatment against leishmaniasis is chemotherapy. Pentavalent antimonials such as glucantime and pentostam have been administrated as the first-line drugs in treatment of various forms of leishmaniasis. The second-line drugs such as amphotericin B, liposomal amphotericin B, miltefosine, pentamidine, azole drugs and paromomycin are used in resistant cases to pentavalent antimonials. Because of drawbacks of the first-line and second-line drugs including adverse side effects on different organs, increasing resistance, high cost, need to hospitalization and long-term treatment, it is necessary to find an alternative drug for leishmaniasis treatment. Several investigations have reported the effectiveness of amiodarone, the most commonly used antiarrhythmic drug, against fungi, Trypanosomes and Leishmania spp. in vitro, in vivo and clinical conditions. Moreover, the beneficial effects of dronedarone, amiodarone analogues, against Trypanosoma cruzi and Leishmania mexicana have recently been demonstrated and such treatment regimens resulted in lower side effects. The anti- leishmanial and anti- trypanosomal effectiveness of amiodarone and dronedarone has been attributed to destabilization of intracellular Ca²⁺ homeostasis, inhibition of sterol biosynthesis and collapse of mitochondrial membrane potential. Because of relative low cost, excellent pharmacokinetic properties, easy accessibility and beneficial effects of amiodarone and dronedarone on leishmaniasis, they are proper candidates to replace the current drugs used in leishmaniasis treatment.