Role of antazoline in cardioversion of atrial fibrillation: A PRISMA-compliant systematic review and meta-analysis

Clinical Snapshot

Key Findings

• P Value: vs propafenone: P = .017; vs amiodarone: P = .018

• Effect Size: vs propafenone: RR 1.13; vs amiodarone: RR 1.22

• Primary Outcome: Conversion to sinus rhythm: antazoline superior to both propafenone and amiodarone

• Nnt Or Sensitivity: NNT cannot be calculated from available data (absolute event rates not reported). Safety outcome risk ratios are statistically unreliable due to extreme CI widths (e.g., bradycardia vs amiodarone: RR 1.36, 95% CI 0–1,072,357.09), indicating near-zero event counts in safety analyses

• Confidence Interval: vs propafenone: 95% CI 1.04–1.23; vs amiodarone: 95% CI 1.08–1.36

Clinical Application

Antazoline is not widely available in most Western healthcare systems. Its use is primarily documented in Poland and some Eastern European countries. Intravenous formulations are not standard stock in Australian emergency departments or cardiology units. Implementation would require regulatory approval, formulary addition, and staff training. The evidence base (5 studies) is insufficient to support formulary adoption in new jurisdictions. Antazoline is not TGA-approved in Australia for antiarrhythmic indications and is not listed on the PBS for this purpose. Current RACGP and NHFA/CSANZ guidelines for AF management recommend established agents including flecainide, amiodarone, and sotalol for pharmacological cardioversion, with electrical cardioversion as an alternative. Australian clinicians should note that this meta-analysis does not provide sufficient evidence to justify off-label use of antazoline outside of a clinical trial setting. The results are not directly applicable to Australian practice without TGA evaluation and local safety data. Adults presenting with recent-onset atrial fibrillation in emergency or acute cardiology settings where rapid pharmacological cardioversion is indicated and antazoline is available

Abstract

BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Antazoline, a first-generation antihistamine with antiarrhythmic properties, has shown efficacy in the rapid conversion of recent-onset AF to sinus rhythm; however, direct comparative evidence against standard antiarrhythmic agents remains limited. This study aims to systematically evaluate the efficacy and safety of antazoline for pharmacological cardioversion of AF, in comparison with standard antiarrhythmic agents such as amiodarone and propafenone. METHODS: The methodology of this systematic review and meta-analysis adhered to the preferred reporting items for systematic reviews and meta-analyses guidelines. A systematic search was conducted in ScienceDirect, Embase, PubMed, and Cochrane Library from inception to April 2025, including citation and reference screening. Statistical analyses were performed using R version 2025.05.0 + 496. RESULTS: From 172 records, 5 studies comparing antazoline with propafenone (n = 5) or amiodarone (n = 3) for AF were included. For antazoline vs propafenone, conversion to sinus rhythm favored antazoline (risk ratio [RR] 1.13 [95% confidence interval (CI): 1.04-1.23], P = .017). No significant difference was observed in time to conversion (mean difference -10.98 [95% CI: -124.93-102.98], P = .436), bradycardia (RR 0.84 [95% CI: 0.35-2.03], P = .478), hypotension (RR 0.40 [95% CI: 0.14-1.12], P = .056), or other adverse events (RR 1.24 [95% CI: 0.01-247.13], P = .694). For antazoline vs amiodarone, conversion to sinus rhythm favored antazoline (RR 1.22 [95% CI: 1.08-1.36], P = .018, I2 = 0%), with no significant differences in bradycardia (RR 1.36 [95% CI: 0-1072357.09], P = .823) or hypotension (RR 1.05 [95% CI: 0.04-26.16], P = .877). CONCLUSION: Antazoline might be more effective than propafenone and amiodarone in achieving sinus rhythm in AF, with no significant differences in safety outcomes.

References

1. 1.Bakht, D., Arham, M., Yousaf, F., Amir, M., Baloch, M. A., Munir, T., Batool, F., Gulzar, E., Rashid, Z., Bokhari, S. F. H., Awais, M. N., Bakht, K., Haris, H. M., Saleem, F., & Saad, M. (2026). Role of antazoline in cardioversion of atrial fibrillation: A PRISMA-compliant systematic review and meta-analysis. Medicine. https://doi.org/10.1097/MD.0000000000049933