The Effect of Pink Grapefruit Juice on the QT Interval in Healthy Volunteers and Patients With Congenital Long QT Syndrome
Abstract
The list of medications that prolong the QT interval and can provoke torsade de pointes keeps expanding. This list includes not only antiarrhythmic drugs, but also medications with no cardiac indications. All these medications prolong the QT interval because they block a specific potassium channel on the myocardial cell membrane: the channel for the rapid component of the delayed rectifier potassium current or "IKr". The risk for developing torsade de pointes for patients taking any of the medications with IKr blockade capabilities varies from \>4% for antiarrhythmic drugs to \<0.01% for non-cardiac medications. The risk depends on the strength of IKr blockade, but also on specific patient characteristics. The majority of patients who develop torsade de pointes from non-cardiac medications have identifiable risk factors. In this regard, patients with a congenital long QT syndrome are prone to develop torsade de pointes when treated with QT-prolonging medications. This is because, due to their genetically defective ion channels, patients with Long QT Syndrome (LQTS) have impaired ventricular repolarization and reduced "repolarization reserve." Therefore, it is common medical practice to strongly advise patients with congenital LQTS to avoid all medications that have IKr channel blocker capabilities. it was reported that some flavonoids contained in pink-grapefruit juice block the IKr channel. These investigators also reported that drinking 1 liter of pink-grapefruit juice…
How strong is the evidence?
Evidence Hub reads this as a clinical trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 25 participants or records.
Read the paper
Related studies
- Synthesis, In Vitro and In Silico Molecular Docking Studies of Novel Phthalimide–Pyrimidine Hybrid Analogues to Thalidomide as Potent Antitubercular Agents
- Exploring the inhibitory performance of expired moxifloxacin and norfloxacin on copper corrosion in saline environment
- Molecular investigation of antimicrobial peptides against Helicobacter pylori proteins using a peptide-protein docking approach
- Screening of novel narrow-spectrum benzofuroxan derivatives for the treatment of multidrug-resistant tuberculosis through in silico, in vitro, and in vivo approaches
- Synthesis, Characterization, Anticancer, Antioxidant, and In Silico Evaluation of Semicarbazides and Thiosemicarbazides
- Fast and accurate prediction of drug induced proarrhythmic risk with sex specific cardiac emulators
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.