thanks for posting on HCM,
contains the active ingredient clarithromycin and either comes in 250mg or 500mg dose (the medication also contain nonmedical ingredients). The drug has several side effects and palpitation
or abnormal heart rhythm may present as an abnormal side effect. The best way to determine for sure if the medication is responsible is by staying off it for a while or completing treatment and observing if you still present with the same problem.
Hope this helps