SOTALOL PROARRHYTHMIA - A REPORT OF 5 CASES AND AN AUDIT OF THE USE OF SOTALOL IN A TEACHING HOSPITAL

Background: Polymorphic ventricular tachycardia is an uncommon complic ation of sotalol use. Aims: The aims of this study were: (1) to report five cases of sotalol proarrhythmia and (2) to audit the use of sotal ol in a teaching hospital population. Methods: Five patients with sota lol proarrhythmia (defined as new ventricular arrhythmias associated w ith sotalol administration) were identified over an 18 month period. S otalol use for patients admitted to the John Hunter Hospital was audit ed over a six month period with 85 patients (55 males) identified from the pharmacy database. Medical records were reviewed and the details of treatment including sotalol dose and indication determined. Creatin ine clearance was estimated by the Cockcroft and Gault regression equa tion. Results: The audit indicated that sotalol was prescribed predomi nantly for management of atrial arrhythmias (80%). Paroxysmal atrial f ibrillation was the most common indication (71%). Although female pati ents were older (72+/-13 vs 62+/-15 years, p<0.001) and had a lower cr eatinine clearance (55+/-24 vs 82+/-32 mg/minute, p<0.001) than male p atients, they were prescribed similar doses of sotalol (206+/-112 vs 1 93+/-93 mg/day). The ratio of sotalol dose to creatinine clearance was higher in female patients (4.0+/-2.6 vs 2.16+/-1.5, p<0.01). The five patients with proarrhythmia (torsades de pointes in four patients and polymorphic ventricular tachycardia in one patient) were all female. Daily sotalol dose (odds ratio for each 160 mg tablet 4.9 [95% confide nce interval 1.5-16] and female gender (p<0.01) were significant risk factors for proarrhythmia. Conclusion: Sotalol dose was not appropriat ely adjusted for creatinine clearance which is age and gender dependen t. Female patients have an increased risk of proarrhythmia and should receive lower doses of sotalol.