Long QT Syndrome (LQTS) can be either an inherited disorder or acquired, often through the use of certain medications. Acquired LQTS is typically caused by drugs that prolong the cardiac QT interval, potentially leading to torsades de pointes, a specific type of life-threatening arrhythmia. Here is a list of drug classes known to cause long QT:
- Antiarrhythmic Drugs
- Class IA (Quinidine, Procainamide)
- Class III (Sotalol)
- Calcium Channel Blockers (Diltiazem, Verapamil)
- Antibiotics
- Macrolides (Erythromycin, Clarithromycin)
- Fluoroquinolones (Ciprofloxacin, Levofloxacin)
- Antifungal Agents (Fluconazole, Ketoconazole)
- Typical Antipsychotics (Haloperidol)
- Atypical Antipsychotics (Ziprasidone, Quetiapine)
- Selective Serotonin Reuptake Inhibitors (SSRIs) (Citalopram, Escitalopram)
- Note that sertraline is fine
- Tricyclic Antidepressants (Amitriptyline, Clomipramine)
- 5-HT3 Receptor Antagonists (Ondansetron, Granisetron)
- Antimalarials (Chloroquine, Quinine)
- Gastrointestinal Prokinetics (Domperidone)
- Methadone
When prescribing these medications, it’s crucial to consider the risk of QT prolongation, especially in patients with existing heart conditions, electrolyte imbalances, or when using other medications that prolong the QT interval. Regular ECG monitoring and electrolyte management are recommended in high-risk patients. This list is not exhaustive, and for the most current information, it’s advisable to consult drug prescribing information or a drug interaction database.