Can trazodone be given to a patient with QTc (corrected QT interval) prolongation?

Trazodone Should Be Avoided in Patients with QTc Prolongation

Trazodone is contraindicated or should be avoided in patients with known QT prolongation, as the FDA drug label explicitly states that "the use of Trazodone Hydrochloride Tablets should be avoided in patients with known QT prolongation" and warns that trazodone prolongs the QT/QTc interval and may cause cardiac arrhythmias including torsades de pointes. 1

FDA Drug Label Warnings

The trazodone FDA label provides clear guidance on this issue:

• Trazodone should be avoided in patients with a history of cardiac arrhythmias and in circumstances that increase the risk of torsades de pointes, including congenital prolongation of the QT interval 1
• Trazodone may be arrhythmogenic in patients with preexisting cardiac disease, with identified arrhythmias including isolated PVCs, ventricular couplets, tachycardia with syncope, and torsades de pointes 1
• Post-marketing events, including torsades de pointes, have been reported at doses as low as 100 mg or less 1
• Trazodone should also be avoided in patients with symptomatic bradycardia, hypokalemia, or hypomagnesemia—all of which are risk factors for torsades de pointes 1

Guideline Support

Multiple cardiology guidelines reinforce this recommendation:

• The American Heart Association identifies trazodone as a medication implicated in torsades de pointes in patients with purposeful overdose, noting it has been associated with QTc prolongation 2
• The ACC/AHA/ESC guidelines on ventricular arrhythmias recommend removal of offending agents in patients with drug-induced long QT syndrome as a Class I indication 2
• Risk factors that compound the danger include female gender, hypokalemia, bradycardia, congestive heart failure, baseline QT prolongation, and concomitant use of other QT-prolonging drugs 2

Recent Clinical Evidence

Recent case reports demonstrate the real-world danger:

• A 2024 case report described a 67-year-old woman who developed torsades de pointes after only 6 days of trazodone 50 mg daily, with QTc prolongation to 586 ms, requiring temporary pacemaker placement 3
• The authors emphasized that trazodone may lead to QTc prolongation and potentially fatal torsades de pointes even without risk factors for QTc prolongation 3
• A 2023 case report documented a patient who developed progressive QTc prolongation to 586 ms and hypotension after trazodone overdose, requiring ICU admission 4
• A 2022 retrospective study of poison center exposures found that trazodone was statistically significantly associated with QTc > 500 ms, despite not being on the CredibleMeds "Known Risk of TdP" list 5

Drug Interactions That Increase Risk

The FDA label specifically warns against combining trazodone with:

• Strong CYP3A4 inhibitors (itraconazole, clarithromycin, voriconazole), which increase trazodone exposure and cardiac arrhythmia risk 1
• Class 1A antiarrhythmics (quinidine, procainamide, disopyramide) 1
• Class 3 antiarrhythmics (amiodarone, sotalol) 1
• Certain antipsychotics (ziprasidone, chlorpromazine, thioridazine) 1
• Certain antibiotics (gatifloxacin) 1
• A 1995 case report documented polymorphous ventricular tachycardia when trazodone was added to previously well-tolerated amiodarone therapy 6

Alternative Medications

For patients requiring treatment of depression or insomnia who have QTc prolongation:

• Benzodiazepines like lorazepam can be safely administered as they are not associated with QT prolongation or torsades de pointes 7
• Among antidepressants, selective serotonin reuptake inhibitors (SSRIs) as a class have limited data linking them to QTc prolongation, though citalopram appears more likely than others to induce this phenomenon 8
• The frequency of cardiac monitoring should be determined based on the prescribed agent(s) and additional risk factors for torsades de pointes 8

Clinical Pitfalls to Avoid

• Do not assume low doses are safe: Torsades de pointes has been reported with doses as low as 100 mg or less 1
• Do not overlook subclinical risk factors: Trazodone can expose subclinical congenital long QT syndrome 2
• Do not combine with other QT-prolonging medications: The risk is substantially increased with concomitant use of multiple QT-prolonging drugs 2, 1
• Do not neglect electrolyte monitoring: Hypokalemia and hypomagnesemia significantly increase the risk of torsades de pointes 2, 1