If you're caring for someone who's had a heart attack, chances are that person has already undergone emergency treatment, with clot-busting drugs, angioplasty, or bypass surgery. But even after the danger has passed, some treatments will be ongoing. Between medications to improve heart function, treat arrhythmias, or manage coronary artery disease, someone who's had a heart attack may be taking what seems like an entire pharmacy of drugs. Knowing how they work and what side effects they may have can help you manage these medications.