Mizolastine

How it works

It selectively and competitively blocks peripheral histamine H1 receptors, reducing the vasodilatation, increased vascular permeability and pruritus driven by histamine release.

Prescribing in practice

• Avoid in patients with significant cardiac disease, QT prolongation or clinically relevant bradycardia, and with drugs that prolong the QT interval, because of a potential for QT effects.
• It is contraindicated in significant hepatic impairment and should be avoided with potent inhibitors of its metabolism.
• Use the modified-release preparation whole and follow the SPC, as it is intended for once-daily dosing.

Monitoring

Routine laboratory monitoring is not generally required, but review cardiac risk factors and concomitant QT-prolonging therapy before and during treatment.

Counselling the patient

• Advise that although drowsiness is uncommon, alcohol should still be avoided until effects are known.
• Tell the patient to swallow the modified-release tablet whole, once daily.
• Recommend reporting palpitations or fainting promptly.

Evidence & guidelines

Mizolastine is a licensed second-generation antihistamine; its efficacy in allergic rhinitis and urticaria is supported by its SPC and the general evidence base for non-sedating antihistamines.