Mizolastine

Oral
Allergic conditions

Significant cardiac or hepatic disease; electrolyte imbalance, particularly hypokalaemia; known or suspected QT prolongation. Clinically significant bradycardia.

May impair ability to drive or operate machinery. Elderly. Pregnancy (avoid in 1st trimester) and lactation.

Dry mouth, diarrhoea, abdominal pain, nausea; transient drowsiness, headache, dizziness; anxiety and depression; raised liver enzymes: low neutrophil count; transient asthenia, increased appetite associated with wt gain; allergic reactions e.g. angioedema, generalised rash/urticaria, pruritus and hypotension; tachycardia, palpitations; vasovagal attack; arthralgia and myalgia.
Potentially Fatal: Anaphylaxis.

General symptomatic treatment with cardiac monitoring including QT interval and cardiac rhythm for at least 24 hr is recommended. Haemodialysis may not be helpful.

Antidepressants and anxiolytics may enhance sedative effect. Potent inhibitors of or substrates for the hepatic metabolism of mizolastine (e.g. cimetidine, ciclosporin, nifedipine) may alter its metabolism.
Potentially Fatal: Increased risk of cardiac arrhythmias with drugs known to prolong the QT interval e.g. class I and III antiarryhthmics. Increased plasma concentrations with macrolide antibiotics and imidazole antifungals.

Description: Mizolastine, a non-sedating antihistamine, blocks histamine H₁-receptors on effector cells of the GI tract, blood vessels and respiratory tract. It also has mast-cell stabilising properties.
Pharmacokinetics:
Absorption: Absorbed rapidly from the GI tract (oral); peak plasma concentrations after 1.5 hr.
Distribution: Protein-binding: 98%.
Metabolism: By glucuronidation (main pathway) or by cytochrome P450 isoenzyme CYP3A4 forming inactive hydroxylated metabolites.
Excretion: 13 hr (elimination half-life).

Do not store above 25°C.

Antihistamines & Antiallergics