Issues for Surgery 


For vestibular disorders – exacerbation of symptoms (e.g. vertigo, tinnitus, nausea and vomiting in Ménière’s disease) if omitted.


  Advice in the Perioperative period 


Elective and Emergency Surgery

Continue – including the following combination product:
  • Cinnarizine and dimenhydrinate
Post-operative Advice

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


  Interaction(s) with Common Anaesthetic Agents 


CNS Depression see also Interaction(s) with other Common Medicines used in the Perioperative Period 

Sedating antihistamines have CNS depressant effects which may be additive with other medicines that also have CNS depressant effects such as 1, 2, 3:-
  • benzodiazepines
  • inhalational anaesthetics and intravenous anaesthetics
  • local anaesthetics
  • opioids
(Consult British National Formulary for available drugs in each class)

For combination product containing dimenhydrinate
The antimuscarinic action of dimenhydrinate may be additive with agents that also have antimuscarinic effects such as atropine and glycopyrronium 1.


   Interaction(s) with other Common Medicines used in the Perioperative Period 


CNS Depression see also Interaction(s) with Common Anaesthetic Agents

Sedating antihistamines have CNS depressant effects which may be additive with other medicines that also have CNS depressant effects such as 1, 2, 3: -
  • antiemetics (e.g. cyclizine, prochlorperazine)
  • opioids

(Consult British National Formulary for available drugs in each class) 

Seizure threshold

Cinnarizine may lower the seizure threshold; concurrent use with other drugs that lower the seizure threshold (e.g. tramadol) might result in additive effects 3

For combination product containing dimenhydrinate

Antiemetics
The antimuscarinic action of dimenhydrinate may be additive with antiemetics that also have antimuscarinic effects such as cyclizine, haloperidol, levomepromazine or prochlorperazine1.

Nefopam
The antimuscarinic action of dimenhydrinate may be additive with nefopam which also has antimuscarinic effects 1.


   Further Information 


None relevant.

  References  


  1. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 15th March 2021]
  2. Summary of Product Characteristics – Cinnarizine 15mg Tablets. Mylan. Accessed via www.medicines.org.uk15/03/2021 [date of revision of the text January 2021]
  3. Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 15th March 2021]