Malegra FXT is a medication used to treat erectile dysfunction (ED) and contains two active ingredients: Sildenafil (the same active ingredient in Viagra) and Fluoxetine (an SSRI antidepressant). While the primary side effects of Sildenafil are usually related to the cardiovascular system (such as dizziness, headaches, or flushing), it is important to note that any medication that affects blood flow or serotonin levels, like Malegra FXT, can potentially have side effects that may affect the heart.

Though irregular heartbeat (arrhythmia) is not a common side effect of Malegra FXT, both Sildenafil and Fluoxetine can have cardiovascular effects that could contribute to irregular heart rhythms in some individuals, especially if they have preexisting heart conditions.

If you or someone you know is experiencing an irregular heartbeat while taking this medication, it's important to consult a healthcare professional immediately, as this could indicate a more serious problem that needs attention.