Craig I. Coleman, PharmD, and Charles W. Jones, PharmD Candidate
Case 1
BC is a 24-year-old man who presents to your New England pharmacy concerned that he may have contracted Lyme disease. He states that he found a tick attached to the back of his left leg. He reports that he believes the tick must have attached to him 2 days ago when he was mowing his lawn. BC removed the tick with tweezers 1 hour ago and placed the tick in plastic bag to show a pharmacist. BC is aware of the high prevalence of Lyme disease in the area and also knows several neighbors that have been diagnosed. BC asks, “What should I do now?”
How should the pharmacist counsel BC?
Case 2
JB is a 66-year-old man who has been in the hospital recovering from an acute ischemic stroke. After receiving alteplase, JB has made excellent progress and is preparing for discharge. His past medical history is significant only for hypertension. The resident writes prescriptions for a statin and some additional antihypertensive medications. The resident wants to start antiplatelet therapy as well, but is unsure of the most appropriate agent to use. The resident contacts the clinical pharmacist seeking a recommendation.
How should the pharmacist handle this prescription?
ANSWERS
Case 1: Lyme disease is the most common tickborne infection in the United States. It is caused by the bacteria Borrelia burgdorferi, which is transmitted to humans from ticks of the genus Ixodes (deer ticks). According to the Infectious Disease Society of America guidelines, prophylaxis of Lyme disease may be offered to patients only under certain circumstances. First, the tick should be identified as adult or nymphal Ixodes scapularis tick estimated to have been attached for greater than 36 hours. Many infectious disease physicians in Lyme endemic areas are able to reliably recognize the I scapularis ticks. Prophylaxis must be started with 72 hours of tick removal. In addition, the local rate of infection of ticks with B burgdorferi should be greater than 20%. This infection rate of ticks generally occurs in parts of New England, parts of the Mid-Atlantic states and in parts of Minnesota and Wisconsin. With the exception of indentifying the tick’s species, BC seems to meet all of the criteria for prophylaxis and should be referred to a physician. If prophylaxis is necessary, BC should be prescribed a single 200-mg dose of doxycycline.
Case 2: There are 4 FDA-approved therapies for the prevention of vascular events among patients with a noncardioembolic stroke or transient ischemic attack: aspirin (typically at doses of 50-100 mg/day), combination aspirin and extended release dipryridamole (Aggrenox), clopidogrel (Plavix) and ticlopidine (Ticlid). According to the 2008 American College of Chest Physicians guidelines, any of these is an “acceptable” initial therapy, but dipryridamole or clopidogrel are preferred over aspirin alone due to better effects on the combined end point of stroke, myocardial infarction, and vascular death. Because ticlopidine can cause life-threatening hematologic reactions, it is typically reserved for patients whom cannot tolerate the other agents. Anticoagulants are only recommended in the treatment of cardioembiolic strokes, such as those caused by atrial fibrillation. The pharmacist should recommend aspirin, dipryridamole, or clopidogrel as an initial choice, but selection among these agents should be based on relative effectiveness, safety, cost, and patient characteristics. If cost is an obstacle, JB might prefer to take aspirin, as this is the most inexpensive agent. If JB is allergic to aspirin, clopidogrel should be started. The use of aspirin plus clopidogrel is not recommended unless a patient has recently experienced an acute coronary syndrome or had a coronary stent placed, due to a substantially increased risk of bleeding complications.
Dr. Coleman is associate professor of pharmacy practice and director of the pharmacoeconomics and outcomes studies group at the University of Connecticut School of Pharmacy. Mr. Perugini is a PharmD candidate from the University of Connecticut School of Pharmacy.
