How long does it take for a drug to leave the body?

I have been taking a drug called kava kava which is an herbal drug I don’t know if anyone is familiar with it or not but a couple days after taking this drug I started having serious heart palpitations. I researched online and I see that this drug is known to cause heart palpitations. Do you think this drug is actually causing the palpitations that I am having and also how long does it take for this drug to leave the system so that I can stop having these side effects? I have been drinking lots of water to see if that helps.