Antispasmodics (Antimuscarinics)

Dicycloverine, Hyoscine butylbromide, Propantheline

  Issues for Surgery

For irritable bowel syndrome, smooth muscle spasm, adult enuresis or hyperhidrosis – loss of symptomatic relief if omitted.

  Advice in the Perioperative period

Elective Surgery

Continue.

EXCEPT: -

• Kolanticon® (dicycloverine + aluminium hydroxide + magnesium oxide + simeticone) – see Antacid monograph.

Post-operative Advice

Resume post-operatively, if needed, once enteral intake resumed.

Review if patient develops reduced gastrointestinal motility (e.g. ileus) post-operatively^{1, 2, 3}.

Review appropriateness of continuing treatment if patient develops post-operative delirium¹.

  Interaction(s) with Common Anaesthetic Agents

Antimuscarinic action

Antimuscarinic action may be additive with agents that also have antimuscarinic effects such as atropine and glycopyrronium^{1, 2, 3}.

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

Delayed Gastric Emptying

Antimuscarinics delay gastric emptying which may alter the absorption of concomitantly administered medication².

Paracetamol
Propantheline reduces the rate, but not the extent, of paracetamol absorption^{2, 4}; other antimuscarinic drugs would be expected to interact similarly⁴. The clinical relevance of this interaction is not known but is likely that a delay in absorption may reduce the rapid pain relief from a single dose of paracetamol but have little impact on repeated dosing⁴.

Prokinetics
Due to the effect of antimuscarinics on gastro-intestinal motility the effectiveness of prokinetic agents e.g. metoclopramide may be reduced^{2, 3}.

 Antimuscarinic action
Antiemetics 
Antimuscarinic action may be additive with antiemetics that also have antimuscarinic effects such as cyclizine, haloperidol, levomepromazine or prochlorperazine^{1, 2, 3}.

Nefopam
Antimuscarinic action may be additive with nefopam which also has antimuscarinic effects¹.

  Further Information

None relevant.

  References

1. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. https://about.medicinescomplete.com/ [Accessed on 14^th March 2021]
2. Summary of Product Characteristics – Pro-Banthine® (propantheline) tablets. Kyowa Kirin Ltd. Accessed via www.medicines.org.uk 14/03/2021 [date of revision of the text October 2018]
3. Summary of Product Characteristics – Buscopan® (hyoscine butylbromide) 10mg Tablets. SANOFI. Accessed via www.medicines.org.uk 14/03/2021 [date of revision of the text April 2020]
4. Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. https://about.medicinescomplete.com/ [Accessed on 14^th March 2021]