Do dabigatran (Pradaxa), diltiazem (Cardizem), carvedilol, spironolactone, telmisartan, and atorvastatin prolong the QT interval?

QT Prolongation Risk of Cardiovascular Medications

None of the medications you listed—dabigatran (Pradaxa), diltiazem (Cardizem), carvedilol, spironolactone, telmisartan, or atorvastatin—are recognized as QT-prolonging agents in major cardiology guidelines. 1

Evidence-Based Assessment by Medication

Dabigatran (Pradaxa)

• Dabigatran does not appear on comprehensive QT-prolonging drug lists from the European Heart Journal, American Heart Association, or FDA guidance documents. 1
• This direct oral anticoagulant works through direct thrombin inhibition and has no known effect on cardiac repolarization channels. 2, 3

Diltiazem (Cardizem)

• Diltiazem prolongs the PR interval through AV nodal blockade but does not significantly prolong the QTc interval as monotherapy. 1
• While diltiazem is mentioned in ICU literature alongside antiarrhythmics, this reflects its use for rate control—not QT prolongation risk. 2
• The critical distinction: diltiazem affects conduction (PR interval) rather than repolarization (QT interval). 1

Carvedilol

• Carvedilol is not listed among QT-prolonging medications in any major guideline or comprehensive drug safety database. 1
• Beta-blockers as a class are actually protective against drug-induced torsades de pointes and are used as adjunct therapy in sodium-channel blocker toxicity. 1

Spironolactone

• Spironolactone does not prolong the QT interval. 1
• In fact, by correcting hypokalemia and hypomagnesemia—two major risk factors for QT prolongation—spironolactone may actually reduce the risk of drug-induced torsades de pointes when used with other medications. 4, 1

Telmisartan

• Telmisartan is not recognized as a QT-prolonging agent in European Heart Journal or American College of Cardiology guidelines. 1
• Angiotensin receptor blockers have no known effect on cardiac ion channels involved in repolarization. 3, 5

Atorvastatin

• Atorvastatin does not appear on any QT-prolonging drug list from major cardiology societies or regulatory agencies. 1
• Statins have no established mechanism for affecting cardiac repolarization. 6, 5

High-Risk Medications That Do Prolong QT

For context, medications that genuinely carry QT prolongation risk include:

• Class IA antiarrhythmics (quinidine, procainamide, disopyramide) and Class III agents (sotalol, dofetilide, amiodarone). 1
• Antipsychotics: thioridazine (25-30 ms increase), haloperidol (7 ms, higher with IV), ziprasidone (5-22 ms). 1, 7
• Macrolide antibiotics: erythromycin (especially IV), clarithromycin, azithromycin. 1
• Fluoroquinolones: moxifloxacin > levofloxacin > ciprofloxacin. 1
• Antiemetics: ondansetron, dolasetron, domperidone. 1
• Antifungals: ketoconazole and other azoles. 1

Common Pitfall to Avoid

Do not confuse PR interval prolongation (AV nodal conduction delay) with QTc prolongation (ventricular repolarization delay). 1 Diltiazem and verapamil prolong the PR interval but are not significant QT-prolonging agents—this is a frequent source of clinical confusion. 1, 2

Clinical Bottom Line

Your medication regimen carries no recognized QT prolongation risk. 1 If QT monitoring is being considered, focus instead on:

• Correcting electrolyte abnormalities (potassium >4.5 mEq/L, normal magnesium). 4, 1
• Reviewing for medications that actually prolong QT (see list above). 1
• Assessing baseline risk factors: female sex, age >65, structural heart disease, bradycardia, congenital long QT syndrome. 4, 1