title: Torsades de Pointes induced by a combination of garenoxacin and disopyramide and other cytochrome P450, family 3, subfamily A polypeptide-4-influencing drugs during hypokalemia due to licorice.
abstract: We report an 82-year-old man who developed ventricular tachycardia and Torsades de Pointes (TdP) after oral administration of garenoxacin, a novel quinolone antibiotic agent that differs from the third-generation quinolones, for pneumonia. He had hypokalemia (K 2.3 mmol/L) induced by licorice and also had received disopyramide for arrhythmia, bicalutamide for prostate cancer, and silodosin for prostate hypertrophy. After taking him off all drugs and administering spironolactone supplemented with potassium, his low serum potassium level was ameliorated. Therefore, although garenoxacin reportedly causes fewer adverse reactions for cardiac rhythms than third-generation quinolone antibiotics, one must be cautious of the interference of other drugs during hypokalemia in order to prevent TdP.
authors.affiliation: Division of Nephrology and Rheumatology, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute-cyo, Aichi 480-1195, Japan.
authors.forename: Kanyu
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Kawai
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Aoyama
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Keisuke
authors.initials: K
authors.lastname: Suzuki
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suga
authors.forename: Wataru
authors.initials: W
authors.lastname: Kitagawa
authors.forename: Naoto
authors.initials: N
authors.lastname: Miura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Imai
mesh_terms: D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D004206:Disopyramide / Q000009:adverse effects*; D024841:Fluoroquinolones / Q000009:adverse effects*; D006035:Glycyrrhiza / Q000009:adverse effects*; D006801:Humans; D007008:Hypokalemia / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D016171:Torsades de Pointes / Q000139:chemically induced*
chemical_list: D000889:Anti-Arrhythmia Agents; D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D004206:Disopyramide; C419689:garenoxacin