SH is an 83 yo Caucasian woman with hypertension prescribed verapamil and HCTZ. She also takes a daily multivitamin, calcium & vitamin D supplements, and a stool softener. She has no known drug allergies. She recently saw a podiatrist for a small ulcer on the bottom of her right foot and was given a prescription for erythromycin. One week later she presents to her PCPs office with complaints of dizziness, weakness, hypotension and bradycardia. Why?
A) Drug-drug interaction between erythromycin and verapamil
B) Drug-nutrient interaction between erythromycin and calcium supplements
C) Drug-disease interaction between erythromycin and hypertension
D) Drug-allergy reaction between erythromycin and HCTZ