Can flecainide cause isolated Serum Glutamic-Pyruvic Transaminase (SGPT) elevation?

Flecainide and Isolated SGPT Elevation

Flecainide can cause isolated elevations of serum transaminase levels, including SGPT (ALT), although these elevations are rare and typically asymptomatic. 1

Evidence of Hepatic Effects

• The FDA drug label for flecainide specifically mentions "isolated elevations of serum transaminase levels" as a reported adverse effect, though these elevations have been asymptomatic and a direct cause-and-effect relationship has not been definitively established 1
• The drug label also notes rare reports of hepatic dysfunction in foreign post-marketing surveillance, including cholestasis and hepatic failure 1
• While flecainide is primarily known for its cardiac side effects, these hepatic effects represent important non-cardiac adverse reactions that clinicians should monitor 1, 2

Clinical Significance and Monitoring

• Transaminase elevations associated with flecainide are generally mild and do not typically require discontinuation of therapy unless accompanied by other signs of hepatic dysfunction 1, 2
• If a patient develops unexplained jaundice or other signs of hepatic dysfunction while on flecainide, it is advisable to discontinue the medication to eliminate it as a possible causative agent 1
• Regular monitoring of liver function tests may be prudent in patients on long-term flecainide therapy, particularly in those with pre-existing hepatic impairment 2

Risk Factors and Special Populations

• Patients with pre-existing hepatic dysfunction require special caution when using flecainide, as noted in multiple guidelines 3
• Renal dysfunction can lead to flecainide accumulation, which may increase the risk of adverse effects, including potential hepatic effects 3, 4
• A case report has documented flecainide toxicity occurring in the setting of acute kidney injury, highlighting the importance of monitoring both renal and hepatic function in patients on this medication 4

Clinical Perspective

• When considering the overall safety profile of flecainide, hepatic effects are relatively rare compared to cardiac adverse effects such as proarrhythmia, conduction abnormalities, and negative inotropic effects 2
• The most common non-cardiac side effects of flecainide are dizziness, visual disturbances, and dyspnea, with hepatic effects being much less frequently reported 1, 2
• In clinical practice, the risk of isolated SGPT elevation should be weighed against the benefits of flecainide in treating supraventricular arrhythmias in appropriately selected patients without structural heart disease 2, 5

Recommendations for Management

• If isolated SGPT elevation occurs in a patient on flecainide, consider:

  1. Assessing for other causes of transaminase elevation 1
  2. Monitoring for development of other signs of hepatic dysfunction 1
  3. Continuing close monitoring if elevation is mild and asymptomatic 2
  4. Discontinuing flecainide if elevation is significant or accompanied by symptoms of hepatic dysfunction 1

• Flecainide should be used with caution in patients with known hepatic dysfunction as explicitly stated in multiple cardiac society guidelines 3

In conclusion, while flecainide can cause isolated SGPT elevations, this is a relatively uncommon adverse effect. Clinicians should be aware of this potential complication and monitor liver function appropriately, especially in patients with risk factors for hepatic dysfunction.