Drugs that can prolong QT interval and torsades de pointes (this list is not comprehensive)
| Antiarrhythmic drugs | Type 1A (TdP reported in all) |
| Quinidine (TdP reported) | |
| Procainamide (TdP reported) | |
| Disopyramide (TdP reported) | |
| Ajmaline (TdP reported) | |
| Type 1C (increase QT by prolonging QRS interval) | |
| Encainide | |
| Flecainide | |
| Type 3 (TdP reported in all) | |
| Amiodarone | |
| Sotalol | |
| d-Sotalol | |
| Bretylium | |
| Ibutilide | |
| Dofetilide | |
| Amakalant | |
| Semantilide | |
| Calcium channel blockers | Prenylamine (TdP reported, withdrawn) |
| Bepridil (TdP reported, withdrawn) | |
| Terodiline (TdP reported, withdrawn) | |
| Psychiatric drugs | Thioridazine (TdP reported) |
| Chlorpromazine (TdP reported) | |
| Haloperidol (TdP reported) | |
| Droperidol (TdP reported) | |
| Amitriptyline | |
| Nortriptyline | |
| Imipramine (TdP reported) | |
| Desipramine (TdP reported) | |
| Clomipramine | |
| Maprotiline (TdP reported) | |
| Doxepin (TdP reported) | |
| Lithium (TdP reported) | |
| Chloral hydrate | |
| Sertindole (TdP reported, withdrawn in the UK) | |
| Pimozide (TdP reported) | |
| Ziprasidone | |
| Antihistamines | Terfenadine (TdP reported, withdrawn in the USA) |
| Astemizole (TdP reported) | |
| Diphenhydramine (TdP reported) | |
| Hydroxyzine | |
| Ebastine | |
| Loratadine | |
| Mizolastine | |
| Antimicrobial and antimalarial drugs | Erythromycin (TdP reported) |
| Clarithromycin (TdP reported) | |
| Ketoconazole | |
| Pentamidine (TdP reported) | |
| Quinine | |
| Chloroquine (TdP reported) | |
| Halofantrine (TdP reported) | |
| Amantadine (TdP reported) | |
| Sparfloxacin | |
| Grepafloxacin (TdP reported, withdrawn in the UK and USA) | |
| Pentavalent antimonial meglumine | |
| Serotonin agonists/antagonists | Ketanserin (TdP reported) |
| Cisapride (TdP reported, withdrawn in the UK and USA) | |
| Immunosuppressant | Tacrolimus (TdP reported) |
| Antidiuretic hormone | Vasopressin (TdP reported) |
| Other agents | Adenosine |
| Organophosphates | |
| Probucol (TdP reported) | |
| Papaverine (TdP reported) | |
| Cocaine |