I just took 2100 mg of tylenol (acetaminophen). how long do i have to wait to have a drink?

You're asking wrong?: You are flirting with an acetaminophen overdose. The maximum amount of acetaminophen which should be taken at one time is 650 mg (they have taken the 500 mg tablets off the market), and you are taking over 3 times this amount. Alcohol increases the toxicity of tylenol. I suspect you are in trouble with both substances. Don't drink any alcohol for at least 24 hours if not longer. Get counseling.