Does Ativan (lorazepam) prolong the QT interval?

From the Guidelines

Ativan (lorazepam) does not typically prolong the QT interval. Unlike some other medications that can affect cardiac repolarization, Ativan belongs to the benzodiazepine class which is generally not associated with QT prolongation. This makes it a safer option for patients who have conditions that put them at risk for QT interval abnormalities or for those taking other medications that do affect the QT interval. The lack of QT prolongation with Ativan is due to its mechanism of action, which primarily involves enhancing the effect of the inhibitory neurotransmitter GABA in the central nervous system rather than affecting cardiac ion channels. Some key points to consider when evaluating the risk of QT prolongation include:

• The medication's known effects on the QT interval, with certain medications like disopyramide, dofetilide, and quinidine being recognized for their potential to cause QT prolongation 1.
• Patient-specific risk factors, such as female gender, hypokalemia, bradycardia, and congenital long QT syndrome, which can increase the risk of torsades de pointes 1.
• The importance of monitoring and managing potential interactions with other medications that may also affect the QT interval, as concomitant use of two or more QT-prolonging drugs can increase the risk of torsades de pointes 1. However, as with any medication, Ativan should be used with caution in patients with certain cardiac conditions, and individual patient factors should always be considered. If QT prolongation is a specific concern for a patient, Ativan is generally considered a safer choice compared to medications known to affect the QT interval, such as certain antipsychotics, antidepressants, or antiarrhythmics.

From the Research

Ativan and QT Interval Prolongation

• Ativan, also known as lorazepam, is a medication used to treat anxiety and other conditions.
• The effect of lorazepam on the QT interval is not extensively discussed in the provided studies, but one study 2 mentions that lorazepam's effect on QT was nullified by correction for heart rate elevation.
• This suggests that lorazepam may not have a significant impact on the QT interval, but more research is needed to confirm this.

QT Interval Prolongation and Its Risks

• QT interval prolongation can increase the risk of Torsades de Pointes (TdP), a potentially life-threatening cardiac arrhythmia 3, 4, 5.
• The risk of QT prolongation is influenced by various factors, including patient-related risk factors, the potential risk and degree of QT prolongation associated with a proposed drug, and co-prescribed medicines 3.
• Electrolyte disorders, such as hypokalemia and hyperkalemia, can also alter cardiac ionic currents kinetics and promote proarrhythmic or antiarrhythmic effects 6.

Management of QT Interval Prolongation

• The management of QT interval prolongation typically involves reducing the medication dosage or discontinuing it altogether, and in some cases, employing selective beta blockers 5.
• Close monitoring of the QT interval is recommended for patients receiving anti-arrhythmic therapy, and consideration should be given to patient-specific risk factors for LQTS, including age, sex, and electrolyte imbalances 5.