- Condition Centers
Dr. Coleman is an assistant professor of pharmacy practice and director of the pharmacoeconomics and outcomes studies group at the University of Connecticut School of Pharmacy.
TT is a 66-year-old woman with newly diagnosed hypothyroidism who comes to the pharmacy with her first prescription for levothyroxine 75 mcg daily and hands it to the pharmacist. The pharmacist pulls up TT?s medication profile and notes that she is taking aspirin 81 mg daily, clopidogrel 75 mg daily, atorvastatin 80 mg daily, and amlodipine 10 mg daily. When asked by the pharmacist, TT admits to having undergone coronary revascularization about 2 months ago after a bout of chest pain.
What concerns should the pharmacist have regarding TT?s new levothyroxine prescription?
SP is a 42-year-old man who goes to the emergency department (ED) complaining of a fever and shortness of breath. SP has a medical history significant for type 2 diabetes and hypertension. He is currently taking metformin, glipizide, and lisinopril. SP has a documented allergy to cephalosporins (described as facial swelling) in his chart. While in the ED, SP is diagnosed with community-acquired pneumonia (CAP) and his doctor decides that he can be treated on an outpatient basis. As part of his discharge instructions, SP is given a prescription for levofloxacin 750 mg daily for 7 days.
Is SP being treated appropriately for CAP?
Levothyroxine (T4) is the drug of choice for replacing thyroid hormone, because it is not associated with a high rate of allergic reactions and exhibits uniform potency. Whereas the average maintenance dose of levothyroxine ranges between 110 and 120 mcg/day, starting doses are typically far less. Although a younger healthy adult might start at a dose of 50 mcg/day, an older patient or one with coronary disease should be started at doses of 25 mcg/day and titrated upward by 25 mcg/day each month until a normal thyroid-stimulating hormone level is achieved (goal: 0.25-6.7 mIU/L). Such a titration scheme will decrease the risk of cardiac toxicity that can be associated with thyroid replacement therapy (heart failure, angina, myocardial infarction). Due to TT?s advanced age and history of cardiac disease, the pharmacist should call the prescriber to discuss a decrease in the levothyroxine dose.
Although the same bacterial organisms typically cause most outpatient CAP (Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae), treatment in most patients is empiric. Current treatment guidelines for CAP (Clin Infect Dis. 2007;44[suppl 2]:S45) recommend that outpatients with comorbid heart, lung, liver, or renal disease, diabetes, alcoholism, or cancer, or who are immunosuppressed, or have received antibiotics in the past 3 months should receive a respiratory fluoroquinolone (eg, moxifloxacin or levofloxacin) or a ß-lactam antibiotic plus a macrolide antibiotic. Because SP has diabetes and a cephalosporin allergy, the use of levofloxacin would be prudent. Patients being treated for outpatient CAP, but without comorbidities, can be treated with a macrolide such as azithromycin.