The Nurse Instructs a Cardiac Patient About the Freshness of Nitroglycerin

The nurse instructs a cardiac patient about the freshness of nitroglycerin sublingual tablets.Which instructions are important for the nurse to tell the patient about the medication? (Select all that apply.)

A) It should be replaced every 3 months.
B) It is no longer good if there is burning under the tongue.
C) It should cause a throbbing in the head.
D) It should cause blurred vision and dry mouth.
E) It should not cause a headache.