What drugs can cause QT prolongation?
- Chlorpromazine.
- Haloperidol.
- Droperidol.
- Quetiapine.
- Olanzapine.
- Amisulpride.
- Thioridazine.
The most potent QT-prolonging medications are antiarrhythmic agents, particularly amiodarone, dofetilide, quinidine, and sotalol, with quinidine possibly having the most torsadogenic potential.
Drugs that cause QTc prolongation
A long QT interval is most frequently seen with class I and class III antiarrhythmic drugs. Other classes of drugs that cause QTc prolongation include antihistamines, antidepressants, antibiotics, antifungal drugs and antipsychotics (Table 2).
Drug-induced electrolyte imbalances, such as hypokalaemia and hypomagnesaemia, which can increase the risk of QT prolongation. for example, loop or thiazide diuretics causing hypokalaemia.
| Drugs to be avoided in patients with c-long QT syndrome | |
|---|---|
| Anti-nausea/antiemetic | Granisetron, Dolasetron, Ondansetron |
| Anti-psychotic | Clozapine, Ziprasidone, Thioridazine, Risperidone, Mesoridazine, Quetiapine, Haloperidol, Pimozide, Amisulpride, Sertindole, Sertindole, Iloperidone, Paliperidone, Chlorpromazine |
Symptoms of long QT syndrome include: Fainting (syncope), which can occur when the heart isn't pumping enough blood to the brain. Irregular heart rhythm (arrythmia) during sleep. Heart palpitations, which feel like fluttering in the chest.
If an underlying medical condition or medication causes it, it's called acquired long QT syndrome. This type of long QT syndrome is usually reversible when the underlying cause is identified and treated.
Because QTc prolongation may be experienced at therapeutic dosages, this medication should be started while the patient is hospitalized. The reported incidence of these proarrhythmic effects is around 5% to 6%, with 1% to 2% of these being TdP. Dofetilide is a selective potassium channel blocker.
Signs and symptoms of Long QT Syndrome
Fainting, especially as a result of acute emotions (such as anger or surprise), exercise, menses (menstruation), or swimming in cold water. Seizures. Ventricular arrhythmias (abnormal heart rhythms originating in the lower chambers) Sudden cardiac arrest.
Medications used to treat long QT syndrome may include: Beta blockers. These heart drugs are standard therapy for most patients with long QT syndrome. They slow the heart rate and make long QT episodes less likely.
Can anxiety cause prolonged QT?
High anxiety is associated with increased QT dispersion, which may predispose to cardiac arrhythmias.
In the field of pain medicine all the major drug classes (i.e. NSAIDs, opioids, anticonvulsive and antidepressant drugs, cannabinoids, muscle relaxants) contain agents that increase the risk of QT prolongation.
Although treatment can help control heart rhythm in patients with this condition, current guidelines discourage patients with long QT syndrome from participating in most competitive sports. Vigorous exercise can trigger an abnormal heart rhythm, and children with the syndrome are at especially high risk of such events.
Abstract. Background: Coronavirus disease-2019 (COVID-19) causes severe illness and multi-organ dysfunction. An abnormal electrocardiogram is associated with poor outcome, and QT prolongation during the illness has been linked to pharmacological effects.
Long QT syndrome (LQTS) is an abnormal feature of the heart's electrical system that can lead to a potentially life-threatening arrhythmia called torsades de pointes (pronounced torsad de pwant). Torsades de pointes may result in syncope (fainting) or sudden cardiac death.
Ann Noninvasive Electrocardiol. 2007 Jul;12(3):251-9. doi: 10.1111/j.
An ECG records your heart's rhythm and electrical activity. If you have long QT syndrome, the trace of the QT section (showing part of the heartbeat) will be longer than normal. Sometimes an exercise ECG will be needed to confirm the diagnosis.
Inherited long QT syndrome (LQTS) is an arrhythmogenic disorder predisposing to sudden cardiac death (SCD) secondary to polymorphic VT; mostly torsades de pointes. The mean age at presentation is 14 years of age, whilst the median age of individuals who die of LQTS is 32 years, with men predominantly affected.
Congenital long QT syndrome can be treated, but it can't be "cured" and won't go away on its own. Acquired long QT syndrome usually stops if the cause (like certain medicines) goes away. Long QT syndrome can affect people of all ages, but is sometimes more serious in children.
Corrected QT interval (QTc)
Fridericia formula: QTC = QT / RR. Framingham formula: QTC = QT + 0.154 (1 – RR) Hodges formula: QTC = QT + 1.75 (heart rate – 60)
Can caffeine cause prolonged QT?
The electrocardiographic effects of caffeine, the main ingredient in energy drinks, have been extensively studied; there is no convincing evidence that caffeine alone causes QTc prolongation.
The diagnosis of “borderline” QT prolongation or even “borderline LQTS” is commonly given when a patient has a QTc value between 440 and 470 ms. 18.
While potassium short- ens QTc interval, magnesium suppresses recurrent TdP without shortening QTc2,8,9,10,11. If TdP occurs, 1-2g of IV magnesium should be administered and repeated if necessary. The use of magnesium prophylactically for long QT with no TdP is debated and not well studied2,12.
Conclusion: The rate-adjusted QT interval is prolonged with increasing age and may contribute to the increased risk of ventricular arrhythmias and cardiac mortality in elderly patients.
You must not drive if you've suffered from: loss of consciousness or fainting. another cardiovascular condition that might affect your ability to drive safely - you must check with your doctor before you drive.
Acetaminophen has not been shown to prolong QT interval or effect cardiac repolarization.
Drug-Induced Supraventricular Arrhythmias
Drugs that may cause or exacerbate AF/AFL (Table 2) include cardiovascular medications, alcohol, stimulants, anticancer agents, and immunomodulators.
Some medications that help balance the heart rhythm may actually cause abnormal heart rhythms in some people. Such medications include certain beta-blockers and sodium channel blockers.
Summary. QT prolongation is the medical term for an extended interval between the heart contracting and relaxing. This condition can increase a person's risk of experiencing abnormal heart rhythms and sudden cardiac arrest. QT prolongation can be present from birth, or it may develop later in life.
LQTS is a congenital condition characterized by prolongation of the QT interval to greater than 440 ms in men and greater than 460 ms in women. Medications like ondansetron in our patient and electrolyte abnormalities like hypokalemia and hypomagnesemia predispose patients with LQTS to TdP.
Does metoprolol prolong QT interval?
Conclusions/interpretation: This study is the first to address the QTc interval and QTc dispersion in Type 1 diabetic patients treated with metoprolol. Beta blocker treatment caused a decrease in QTc interval but no change in QTc dispersion.
The list of drugs known to cause TdP that require a dose adjustment for patients with acute kidney injury or chronic kidney disease include: ciprofloxacin, disopyramide, dofetilide, flecainide, fluconazole, levofloxacin, procainamide, and sotalol.
Ketoconazole, itraconazole, fluconazole, and voriconazole have been shown to prolong the QT interval and to be associated with TdP, with the majority of reports of TdP stemming from drug interactions and involving ketoconazole and itraconazole [74–88]. Akin to the macrolides, the azoles are “dual-risk” agents.
Abstract. Amiodarone is an antiarrhythmic agent known to cause prolongation of action potential duration which is reflected in the electrocardiogram as a prolongation of the QT interval.
Conclusion: Beta-blockers have heart-rate-dependent effects on the QT and QTc intervals in LQTS. They appear to increase the QT and QTc intervals at slower heart rates and shorten them at faster heart rates during exercise.
Beta-blockers are the standard of care for the treatment of long QT syndrome (LQTS), and have been shown to reduce recurrent syncope and mortality in patients with type 1 LQTS (LQT1).
Although treatment can help control heart rhythm in patients with this condition, current guidelines discourage patients with long QT syndrome from participating in most competitive sports. Vigorous exercise can trigger an abnormal heart rhythm, and children with the syndrome are at especially high risk of such events.
Medications used to treat long QT syndrome may include: Beta blockers. These heart drugs are standard therapy for most patients with long QT syndrome. They slow the heart rate and make long QT episodes less likely.
Signs and symptoms of Long QT Syndrome
Fainting, especially as a result of acute emotions (such as anger or surprise), exercise, menses (menstruation), or swimming in cold water. Seizures. Ventricular arrhythmias (abnormal heart rhythms originating in the lower chambers) Sudden cardiac arrest.
Adenosine (Adenocard)
Adenosine is the first-line medical treatment for the termination of paroxysmal SVT.
How common is drug induced QT prolongation?
Because QTc prolongation may be experienced at therapeutic dosages, this medication should be started while the patient is hospitalized. The reported incidence of these proarrhythmic effects is around 5% to 6%, with 1% to 2% of these being TdP. Dofetilide is a selective potassium channel blocker.
After adjusting for the potential or known risk factors for QT prolongation, the use of azithromycin was more likely to be associated with QT prolongation (OR [95% CI], 1.40 [1.23-1.59]), but the use of amoxicillin was not associated with QT prolongation (OR [95% CI], 1.06 [0.97-1.15]).
QT prolongation appears to be a class effect for all selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs), and also occurs with venlafaxine. The potential for QT prolongation to occur should be considered as part of the risk benefit assessment prior to prescribing an antidepressant.
Despite similar BP-lowering effects, the direct renin inhibitor aliskiren, but not the calcium channel blocker (CCB) amlodipine, decreased the duration of the QT interval in these patients. Therefore, pharmacotherapies with similar effects on hypertension will not exert identical effects on cardiac repolarization.
QT interval is inversely correlated with heart rate. Generally, QT intervals are corrected for heart rate so that QTc is equal to QT if the heart rate is 60 beats per minute, i.e., RR interval of 1 s.
Normal QTc interval is 350–450 ms in males and 360–460 ms in females. QTd is the difference between the longest and shortest QT interval on standard ECG.