Antiarrhythmics - Class 1c

Flecainide, Propafenone

  Issues for Surgery

Risk of cardiac arrhythmias if omitted.

Risk of cardiac complications (i.e. bradycardia, hypotension, conduction disturbances and decreased cardiac output) if continued.

Risk of QT-interval prolongation if flecainide is continued (see Interaction(s) with Common Anaesthetic Agents and Interaction(s) with other Common Medicines used in the Perioperative Period).

  Advice in the Perioperative period

Elective and Emergency Surgery
Continue.

If patient is symptomatic (i.e. chest pain, palpitations, syncope, dyspnoea or new fatigue) and haemodynamically unstable discuss with a Cardiologist¹.

Check blood pressure, ECG, and potassium pre-operatively^{1, 2}.

Patients taking flecainide
Ensure the anaesthetist is informed on the day of surgery that the patient is taking flecainide since it may predispose patients to rapid atrial flutter with resultant haemodynamic compromise due to the physiological stress of surgery^{1, 3}.

Post-operative Advice
Restart post-operatively when enteral intake resumed.

Patients taking flecainide`
If patient is unable to take their usual oral flecainide or it needs to be administered via an enteral feeding tube post-operatively, close monitoring is required when switching to a different formulation due to its narrow therapeutic index³.

Monitor renal function post-operatively – renal impairment may result in flecainide accumulation^{2, 3}.

If patient develops systolic heart failure in the perioperative period consult with a Cardiologist¹.

  Interaction(s) with Common Anaesthetic Agents

 
Bradycardia
Flecainide and propafenone can increase the risk of bradycardia when used concomitantly with the following^{2, 4}: -

• alfentanil, fentanyl or remifentanil
• neostigmine
• propofol
• suxamethonium

Local Anaesthetics
Concomitant use of local anaesthetics is predicted to increase the risk of cardiodepression when given with flecainide and propafenone^{2, 4, 5}. Manufacturer advises monitor^{2, 5}.

QT-Interval Prolongation (see also under Interaction(s) with other Common Medicines used in the Perioperative Period)
Flecainide prolongs the QT-interval^{2, 3, 5}. Co-administration of flecainide with other medicines known to prolong the QT-interval must be based on a careful assessment of the potential risks and benefits for each patient since the risk of torsade de pointes may increase.

Anaesthetic agents that may be used in the perioperative period that are known to, or predicted to, prolong the QT-interval include^{2, 5}: -

• desflurane, isoflurane, sevoflurane*
• thiopental (theoretical)**

*monitor ECG if concurrent use unavoidable; if risk factors for QT-prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia) use greater caution.

**monitor ECG with concurrent use particularly if risk factors for QT-interval prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia).

Antimuscarinic action
Antimuscarinic action of propafenone may be additive with agents that also have antimuscarinic effects such as atropine and glycopyrronium².

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

 
Hypokalaemia
Corticosteroids and laxatives may cause hypokalaemia (potentially increasing the risk of torsades de pointes) with flecainide^{2, 3, 5}. The manufacturer makes no recommendation – however if hypokalaemia occurs it should be corrected and QT-interval monitored³.

QT-Interval Prolongation (see also under Interaction(s) with Common Anaesthetic Agents)
Flecainide prolongs the QT-interval^{2, 3}. Co-administration of flecainide with other medicines known to prolong the QT-interval must be based on a careful assessment of the potential risks and benefits for each patient since the risk of torsade de pointes may increase.

Medicines that may be used in the perioperative period that are known to prolong the QT-interval include^{2, 3, 5}:-

• ciprofloxacin*
• clarithromycin*
• domperidone – avoid
• droperidol*
• erythromycin (particularly intravenous)*
• granisetron – avoid if 1 or more risk factors present
• haloperidol**
• loperamide (increased risk with high doses)*
• ondansetron*
• prochlorperazine (theoretical risk)*

*monitor ECG with concurrent use particularly if risk factors for QT-interval prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia).

**monitor ECG if concurrent use avoidable; if risk factors for QT-prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia) use greater caution.

Antimuscarinic action
Antiemetics
Antimuscarinic action of propafenone may be additive with antiemetics that also have antimuscarinic effects such as cyclizine, haloperidol, levomepromazine or prochlorperazine².

Nefopam
Antimuscarinic action of propafenone may be additive with nefopam which also has antimuscarinic effects².

Macrolides
Co-administration of propafenone with macrolide antibiotics (i.e., clarithromycin, erythromycin) might lead to increased levels of propafenone via inhibition of CYP3A4 – manufacturer advises monitor and adjust dose if necessary^{2, 4, 5}.

Whilst single surgical prophylactic doses should not pose a problem, continued post-operative treatment may require close monitoring.

  Further Information

None relevant. 

  References

1. Acker L, Bova Campbell K, Naglee C, Taicher B, Bronshteyn YS. Perioperative Management of Flecainide: A Problem-Based Learning Discussion. Anesthesia & Analgesia Practice. 2021 Apr 1;15(4):1-5.
2. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk/interactions/ [Accessed on 2^nd February 2023]
3. Summary of Product Characteristics – Flecainide 100mg Tablets BP. Aurobindo Pharma - Milpharm Ltd. Accessed via www.medicines.org.uk 09/04/2023 [date of revision of the text December 2022]
4. Summary of Product Characteristics – Arythmol® (propafenone) 150 mg Tablets. Mylan Products Ltd. Accessed via www.medicines.org.uk 09/04/2023 [date of revision of the text March 2021]
5. Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 9^th April 2023]