UK Clinical Pharmacy Association

Mizolastine

Issues for surgery

Loss of symptomatic relief of allergic rhinitis, hay fever and urticaria if omitted.

Risk of QT-interval prolongation if continued.

Advice in the perioperative period

Elective and emergency surgery

Continue. 

Post-operative advice

If taken regularly, restart post-operatively as soon as next dose is due; otherwise restart when symptoms develop.

Interactions with common anaesthetic agents

QT-Interval prolongation 

Mizolastine has a weak potential to prolong the QT-interval in some individuals, which might be additive with the effects of other drugs that prolong the QT-interval. Concurrent use of mizolastine with other medicines known to prolong the QT-interval e.g. desflurane, isoflurane and sevoflurane, and possibly thiopental, is contraindicated by the UK manufacturer.

Interactions with other common medicines used in the perioperative period

Macrolides 

Clarithromycin and erythromycin are predicted to increase the exposure to some non-sedating antihistamines either through inhibition of CYP3A4 (desloratadine, loratadine, mizolastine and rupatadine) or through P-glycoprotein (bilastine and fexofenadine). Acrivastine is expected to be similarly affected, however, they do not appear to have a clinically significant interaction with cetirizine or levocetirizine. 

Concomitant use of clarithromycin is contraindicated by the manufacturers of mizolastine and rupatadine. Concomitant use of erythromycin is contraindicated by the manufacturer of mizolastine and cautioned by the manufacturer of rupatadine.

Whilst single surgical prophylactic doses should not pose a problem in patients taking bilastine, desloratadine, fexofenadine or loratadine monitor for side effects if a prolonged course is required.

QT-Interval prolongation

Mizolastine has a weak potential to prolong the QT-interval in some individuals, which might be additive with the effects of other drugs that prolong the QT-interval. Concurrent use of mizolastine with other medicines known to prolong the QT-interval is contraindicated by the UK manufacturer. 

Medicines that may be used in the perioperative period that are known to prolong the QT-interval include: 

  • ciprofloxacin
  • clarithromycin – see also Macrolides above
  • domperidone
  • droperidol
  • erythromycin (particularly intravenous) – see also Macrolides above
  • granisetron
  • haloperidol
  • loperamide (increased risk with high doses)
  • ondansetron
  • prochlorperazine (theoretical risk) 

Further information

None relevant. 

References

Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 2nd February 2021]

Summary of Product Characteristics – Acrivastine 8mg Capsules, hard. Brown & Burk UK Ltd. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text July 2020]

Summary of Product Characteristics – Ilaxten (bilastine) 20 mg tablets®. A. Menarini Farmaceutica Internazionale SRL. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text August 2019]

Summary of Product Characteristics – Cetirizine 10mg Film-Coated Tablets. Dexcel Pharmaa Ltd. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text June 2019]

Summary of Product Characteristics – Neoclarityn® (desloratadine) 5mg film-coated tablets. Pfizer Limited. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text January 2020]

Summary of Product Characteristics – Telfast® (fexofenadine) 120mg Film-coated Tablets. SANOFI. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text October 2019]

Summary of Product Characteristics – Levocetirizine 5mg film-coated tablets. Glenmark Pharmaceuticals Europe Ltd. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text December 2019]

Summary of Product Characteristics – Rupatadine 10mg Tablets. Aspire Pharma Ltd. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text September 2020]

Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 2nd February 2021] 

Summary of Product Characteristics – Mizollen (mizolastine) 10 mg modified-release tablets. SANOFI Ltd. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text September 2019]

Summary of Product Characteristics – Loratadine 10mg Tablets. Accord-Uk Ltd. Accessed via www.medicines.org.uk 2/2/2021 [date of revision of the text January 2021]