Sotalol

Additional information

Pharmacokinetics and dosing

An open-label randomized parallel study (12 men, 12 women) investigated the pharmacokinetics of intravenous doses of d-sotalol up to 3.0 mg/kg. Volume of distribution at steady-state (Vdss) was found to be 16% lower in women than men [1]. The authors suggest this small difference to not be clinically important. For other pharmacokinetic parameters, there were no differences observed between men and women [1]. Contrary to this, a single dose of 160 mg racemic sotalol to healthy volunteers (28 men, 11 women) resulted in higher mean peak plasma concentrations in women and a larger mean change in QT-interval in women [2].

Despite the small pharmacokinetic differences of sotalol, the clinical studies have shown effect with similar doses in men and women and no sex differentiation in dosing has been suggested [3].

Effects

In a randomized double-blind trial (234 men, 66 women), the efficacy of oral low-dose sotalol was compared with placebo in the prophylactic treatment of supraventricular tachyarrhythmia (SVT) shortly after coronary artery bypass grafting. Men had a less protection by sotalol and therefore developed more postoperative SVTs than women (RR 1.7) [4].

The mortality risk of sotalol in patients after myocardial infarction with left ventricular dysfunction was investigated in the SWORD trial (2679 men, 442 women). Men and women were at a similar risk of death in the overall SWORD population [5].

Adverse effects

Sex differences in the proarrhythmic potential of QT-prolonging drugs are well documented. Women have a greater risk than men of developing dangerous ventricular tachycardias, Torsade de pointes (TdP), when given drugs prolonging repolarization [6]. A meta-analysis of cardiovascular medications report that female sex is a risk factor for drug-induced TdP for many of the analyzed medications, including sotalol. Of the 332 cases of TdP in this meta-analysis, 70% were women [7]. Thus, the occurrence of TdP was independent of dosage and does not appear to be related to any critical serum drug level. It is suggested that this finding could be explained by a female predisposition to prolonged cardiac repolarization. In general, women have a longer average QT-interval than men [7, 8]. Also in further analysis of a database including more than 3000 patients given sotalol for treatment of atrial or ventricular arrhythmias, women were found to be at increased risk of developing TdP when taking the drug; 4.1% of the women vs. 1.0% of the men had TdP [9].

Reproductive health issues

Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).