From the Guidelines
Metronidazole (Flagyl) is not typically associated with bradycardia as a side effect. The common cardiovascular side effects of metronidazole include QT interval prolongation and, rarely, arrhythmias, but bradycardia specifically is not a well-documented adverse effect. The most frequently reported side effects of metronidazole include gastrointestinal disturbances (nausea, vomiting, metallic taste), headache, dizziness, and peripheral neuropathy with prolonged use. When administering metronidazole, it's essential to monitor for neurological symptoms, especially with high doses or extended treatment courses. The medication works by disrupting bacterial DNA, which explains why it doesn't typically affect cardiac conduction pathways that would lead to bradycardia. If a patient experiences unexpected bradycardia while taking metronidazole, other causes should be investigated, as this is unlikely to be directly attributed to the medication itself, as supported by studies such as 1. Some studies, like 1, discuss various medications and their potential to cause bradycardia, but metronidazole is not typically listed among them. Similarly, 1 and 1 provide information on drug interactions and side effects related to cardiovascular health, but they do not specifically link metronidazole with bradycardia. Therefore, based on the available evidence, metronidazole is not commonly associated with bradycardia, and its use should be guided by its known side effect profile and the patient's individual health status.
From the Research
Metronidazole and Bradycardia
- Metronidazole is an antibiotic used to treat various infections, including those caused by anaerobic bacteria and protozoa 2.
- While metronidazole is generally well-tolerated, it can cause side effects such as nausea, abdominal pain, and diarrhea 3.
- There is limited evidence to suggest that metronidazole is directly associated with bradycardia as a side effect.
- However, a study on antibiotic-induced cardiac arrhythmias mentions that modifiable risk factors for arrhythmia induction include bradycardia, but this is in the context of macrolides and fluoroquinolones antibiotics, not metronidazole 4.
- Another study presents a rare case of metronidazole overdose causing ventricular fibrillation, but does not mention bradycardia as a side effect 5.
- A review on evaluating and managing bradycardia discusses the condition in general, but does not mention metronidazole as a potential cause 6.