Question explored with the scientific record
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- 1 Statins can inrease risk of atrial fib
- 2 what drugs increase risk of a fib
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what drugs increase risk of a fib
The short version: the drugs with real atrial fibrillation signals in this evidence are thyroid pills, NSAIDs, and the antiarrhythmics themselves. Most of the rest is thin.
Levothyroxine is the clearest case. A 35-year-old man taking too much developed atrial fibrillation with heart failure, a T4 of 20 against a normal 5 to 12 [2]. That is overdose, not normal dosing. The thyroid link runs both ways: subclinical hyperthyroidism raised AF risk, and higher free T4 within the normal range did too [4]. So the drug that pushes thyroid hormone up is a plausible AF trigger, and the evidence here is a single case plus cohort associations.
| Drug | Signal | Source |
|---|---|---|
| Levothyroxine (excess) | AF with heart failure at T4 20 | [2] |
| NSAIDs after surgery | Mixed; OR 1.43 in one cohort | [5] |
| Sotalol + terfenadine | Torsades 8 days after adding terfenadine | [6] |
| Amiodarone | Hypothyroidism, bradycardia at 37 bpm | [1] |
NSAIDs are genuinely unsettled. One review found a higher post-op AF rate with NSAID use in thoracic surgery, but a 608-patient randomized trial found almost no AF at all, too few to settle anything [5]. The mechanism is plausible: COX-2 inhibition triggered abnormal firing in rabbit pulmonary vein tissue [5].
Amiodarone is the irony. It treats AF, but it caused overt hypothyroidism and a heart rate of 37 in one patient [1], and it blocks thyroid hormone's effect on the heart's sodium pump [3]. Sotalol plus terfenadine produced torsades [6].
What this evidence cannot see: no cohort of ordinary outpatients on these drugs with AF as the measured outcome. The signals are case reports and surgical settings.
My call: excess thyroid hormone and the sotalol-terfenadine combination are the credible AF triggers here; NSAIDs are plausible but unproven. Confidence: low to moderate.
Sources used 6
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Amiodarone-Induced Hypothyroidism
In a 61-year-old woman with pre-existing subclinical hypothyroidism and paroxysmal atrial fibrillation, amiodarone therapy was followed by overt hypothyroidism and bradycardia; thyroid function normalized after withdrawal but atrial fibrillation recurred.
DOI: 10.25207/1608-6228-2019-26-6-127-134 -
Clinical Therapeutic Conference: Excess Synthroid Ingestion Presenting as Congestive Heart Failure
This case study discusses a 35-year-old man who developed congestive heart failure and atrial fibrillation due to excessive ingestion of levothyroxine, highlighting the cardiovascular effects of thyroid hormone dysregulation.
DOI: 10.1002/j.1552-4604.1992.tb03781.x -
Amiodarone Inhibits the 3,5,3′-Triiodothyronine-Dependent Increase of Sodium/Potassium Adenosine Triphosphatase Activity and Concentration in Human Atrial Myocardial Tissue
Amiodarone antagonizes thyroid hormone–dependent upregulation of Na+/K+-ATPase activity and pump-site concentration in human atrial myocardial tissue.
DOI: 10.1089/1050725041517084 -
Challenges in the Management of Atrial Fibrillation With Subclinical Hyperthyroidism
This narrative review reports that subclinical hyperthyroidism is associated with incident atrial fibrillation, management should aim for euthyroidism and standard AF strategies, and wearable ECG screening was feasible but neutral in a large trial, with limited randomized treatm…
DOI: 10.3389/fendo.2021.795492 -
Do nonsteroidal anti-inflammatory drugs increase the risk of atrial fibrillation after non-cardiac surgery? Insights from translational and clinical research
This narrative review integrates preclinical translational data and clinical evidence to evaluate whether perioperative nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk of postoperative atrial fibrillation (POAF) after non-cardiac surgery, outlining plausible mech…
DOI: 10.1186/s44158-025-00303-5 -
Torsades de Pointes from Terfenadine and Sotalol Given in Combination
In a 71-year-old woman on sotalol, recurrent torsades de pointes appeared 8 days after terfenadine was added and ceased after both drugs were stopped.
DOI: 10.1111/j.1540-8159.1996.tb03169.x