A patient with a cardiac history complains of chest pain. He already took four baby aspirins and medical direction has given you the go ahead to assist the patient with his nitroglycerin. After administering nitroglycerin to the patient, he complains of a headache. Which of the following is appropriate?

A) Inform the patient that he is allergic to nitroglycerin.
B) Administer additional aspirin for the headache.
C) Recognize a contraindication to the administration of nitroglycerin.
D) Realize an undesirable side effect of the nitroglycerin and continue care.

D