What can u drink to lower your heart rate?

Good old water along with some slow deep breathing will do the trick

Heart rate can vary from time to time due to a number causes such as exertion, emotional state, fever or infection if any. Your question lacks any useful detail with regard to the actual heart rate is or was. Under the circumstances, the best answer would be to ask you to discuss this with your doctor who is familiar with your health status as well as the medications.