An Unusual Side Effect of Acyclovir: Junctional Rhythm-Poonam Patel

Sun, 17 Aug 2025 21:46:50 +0000

Co-Authors: Vagharsh Antanesian, MD MPH, Internal Medicine, PGY 3,Norton Community Hospital Norton, VA

Introduction: Acyclovir, an antiviral agent primarily targeting Herpes Simplex Virus (HSV) infections, presents predominantly mild adverse effects such as malaise (10%), gastrointestinal symptoms, and elevated liver function tests (1-10%). However, more severe complications, notably associated with intravenous administration, encompass rare occurrences of acute renal failure, neurological toxicity, and sporadic cases of bradycardia. A review of literature revealed 2 instances linking acyclovir to bradycardia, with no documented reports on junctional rhythm. A phase IV clinical study examining FDA data identified 1,424 individuals encountering side effects from Acyclovir, with only 6 individuals (0.42%) reporting bradycardia, primarily observed in males aged 60 and above using the medication for less than a month. Here we report a rare case of junctional rhythm caused by acyclovir.

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