If the two drugs are coadministered, the beta-blocker should be withdrawn several days before the gradual withdrawal of clonidine. Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. If your doctor tells you to check your pulse regularly while you are taking this medicine, and it is much slower than the rate your doctor has designated, check with your doctor. Use cautiously in the renally impaired dosage adjustment required. Hypokalemia can sensitize or exaggerate the response of the heart to the toxic effects of digitalis eg, increased ventricular irritability. This is to make sure the medicine is working for you and to allow the dosage atenolol no rx to be changed if needed.