From the Guidelines
Tigan can potentially prolong the QTc interval, and its use should be approached with caution in patients with pre-existing QT prolongation or other risk factors. When considering the effect of Tigan on the QTc interval, it is essential to weigh the potential risks and benefits, particularly in patients with underlying cardiac conditions or those taking other QT-prolonging medications. The mechanism behind Tigan's effect on the QTc interval involves its ability to block certain cardiac ion channels, particularly potassium channels, which can delay cardiac repolarization and extend the QT interval 1. According to the 2016 ESC position paper on cancer treatments and cardiovascular toxicity, patients with a history of QT prolongation, relevant cardiac disease, or those treated with QT-prolonging drugs should be monitored by repeated 12-lead ECG 1. Key points to consider when monitoring the QTc interval include:
- Measuring the QT interval from the beginning of the QRS complex to the end of the T wave
- Correcting the QT interval for heart rate using Bazett's or Fridericia's formula
- Avoiding conditions that provoke torsade de pointes, such as hypokalaemia and extreme bradycardia
- Minimizing exposure to other QT-prolonging drugs in patients treated with potentially QT-prolonging medications 1. For high-risk patients, baseline and follow-up ECG monitoring may be appropriate when using Tigan, especially at higher doses or with prolonged use 1. Alternative antiemetics with less QT effect might be preferable in patients with significant cardiac risk factors. It is crucial to note that the QTc interval has never been validated as a predictor for torsades de pointes, and the QTC interval should be interpreted with caution 1. A normal QTC is 0.46 second in women and 0.45 second in men, and a QTC of 0.50 second in either sex has been shown to correlate with a higher risk for torsades de pointes 1.
From the Research
Effect of Tigan on QTc Interval
- There is no direct evidence in the provided studies that specifically mentions the effect of Tigan on the QTc interval.
- However, the studies discuss the mechanisms and risk factors for drug-induced QT interval prolongation, which can be associated with various medications 2, 3, 4, 5, 6.
- Some studies mention that certain drugs, such as antiarrhythmic drugs, antibiotics, and antipsychotics, can prolong the QTc interval and increase the risk of Torsades de Pointes (TdP) 3, 4, 6.
- It is essential to note that Tigan is not explicitly mentioned in the provided studies, and therefore, its effect on the QTc interval cannot be determined based on the available evidence.
- In general, it is crucial to monitor the QTc interval and assess the risk of TdP when administering medications that can prolong the QTc interval, especially in patients with underlying risk factors 5, 6.