Issues for surgery
Loss of symptomatic relief of pruritis, hay fever, food allergy and urticaria if omitted.
Advice in the perioperative period
Elective and emergency surgery
Continue.
Post-operative advice
If taken regularly, restart post-operatively once enteral intake resumed, otherwise restart if symptoms develop.
Interactions with common anaesthetic agents
CNS depression
See also Interactions with other common medicines used in the perioperative period.
Chlorphenamine has CNS depressant effects which may be additive with other medicines that also have CNS depressant effects such as:
- benzodiazepines
- inhalational anaesthetics and intravenous anaesthetics
- local anaesthetics
- opioids
(Consult British National Formulary for available drugs in each class)
Case reports describe increased respiratory depression with concomitant use of chlorphenamine and fentanyl.
Antimuscarinic action
The antimuscarinic action of chlorphenamine may be additive with agents that also have antimuscarinic effects such as atropine and glycopyrronium.
Interactions with other common medicines used in the perioperative period
CNS depression
See also Interactions with common anaesthetic agents.
Chlorphenamine has CNS depressant effects which may be additive with other medicines that also have CNS depressant effects such as:
- antiemetics (e.g. cyclizine, prochlorperazine)
- opioids
(Consult British National Formulary for available drugs in each class)
Antimuscarinic action
Antiemetics
The antimuscarinic action of chlorphenamine may be additive with antiemetics that also have antimuscarinic effects such as cyclizine, haloperidol, levomepromazine or prochlorperazine.
Nefopam
The antimuscarinic action of chlorphenamine may be additive with nefopam which also has antimuscarinic effects.
Further information
None relevant.
References
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 2nd October 2023]
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 2nd October 2023]
Summary of Product Characteristics – Piriton® (chlorphenamine) Tablets. Haleon UK Trading Limited. Accessed via www.medicines.org.uk 02/10/2023 [date of revision of the text April 2023]