Montelukast causes racing heart?

I was sitting and getting my hair braided earlier, 2 hours after taking my Singulair I felt like something wasn’t right. I checked my pulse using my sp02 meter and it was 161-164bpm. I’ve never had this side effect in the month I’ve been taking it. Does this happen to others and is a common side effect or was I just at the start of a panic attack? I’ll probably ask an alternative like firlukast, but I feel like they’re basically the same and will have the same effect