<p>Mizolastine is contra-indicated in patients with clinically significant cardiac disease or a history of symptomatic arrhythmias and in patients with known or suspected QT prolongation, patients with electrolyte imbalance (particularly hypokalaemia), and in those with clinically significant bradycardia. It is also contra-indicated in patients taking other drugs that decrease its metabolism, patients with significantly impaired liver function, and in patients who are hypersensitive to the drug.</p>