A 67-year-old chronic smoker with COPD and chronic heart failure presents to his primary care physician for follow-up. The patient takes multiple medications for these problems. Which of the following strategies may prove to have additional benefit in the treatment of this patient?

A 67-year-old chronic smoker with COPD and chronic heart failure presents to his primary care physician for follow-up. The patient takes multiple medications for these problems. Which of the following strategies may prove to have additional benefit in the treatment of this patient?

The following are modifiable risk factors for the genesis of atheromatous plaque:

Intravenous verapamil:

A 64-year-old man with coronary atherosclerosis and 'mild' heart failure has been treated with digoxin and several other drugs. He complains of nausea, vomiting, and diarrhea. His ECG reveals a bigeminal rhythm and second-degree heart block. A drug-drug interaction is suspected. Which of the following coadministered drugs most likely provoked the problem?