- 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.
A mother, on behalf of her 17-year-old daughter, arrives at the pharmacy counter and presents a prescription for azithromycin 500 mg 3 times weekly to a fourth-year pharmacy student intern. The student is confused about the azithromycin dosing prescribed and, eager to make a valuable clinical recommendation, excitedly walks over to his precepting pharmacist to ask if he can call the physician to get the prescription changed to the common Z-pak dosing. The pharmacist and student look up the daughter's profile and note that she is receiving pancreatic enzymes, an ADEK vitamin supplement, inhaled tobramycin, dornase alfa, and nebulized albuterol.
How should the pharmacist respond to the pharmacy student?
MK is a 76-year-old woman who was recently seen at an outpatient clinic following a fall. She was given a bone mineral density scan and was found to have a T-score at the spine of -1.8 and at the hip of -2.6. The physician at the clinic gives her a prescription for alendronate 70 mg by mouth weekly, and she brings the prescription into the pharmacy. The pharmacist reviews MK's profile and sees that she is also taking simvastatin, lisinopril, lansoprazole, and calcium carbonate plus vitamin D. MK tells the pharmacist that she feels fine and does not understand why she should take this medication. She also asks if it is true that she has to stand up for 2 hours after she takes the alendronate.
What should the pharmacist tell the patient?
Based on the patient's prescription profile, it is clear that the patient has cystic fibrosis. Azithromycin is thought to modulate a cystic fibrosis patient's overactive inflammatory response, resulting in improvements in pulmonary function, nutritional status, health-related quality of life, and decreases in pulmonary exacerbation rates (particularly in patients chronically infected with Pseudomonas). Current cystic fibrosis treatment guidelines state that the use of azithromycin is associated with a "substantial" net benefit to the patient and recommends doses in the range of 250 to 500 mg 3 times weekly. (Flume PA, O'Sullivan BP, Robinson KA, et al. Cystic fibrosis pulmonary guidelines: chronic medications for maintenance of lung health. Am J Respir Crit Care Med. 2007;176(10):957-969.) The pharmacist should tell the student that the prescription is correct as written.
Osteoporosis is due to an imbalance of bone formation and resorption, and may lead to complications such as fractures. Diagnosis is typically made by measuring the T-score, which compares a patient's bone mineral density with a young healthy person of the same sex. A T-score <-2.5 is diagnostic for having osteoporosis. Based on MK's T-score at the hip (-2.6), she is considered to have osteoporosis and should receive treatment to prevent fractures. The pharmacist should tell the patient that her alendronate should help to keep her bones strong, so that she would be less likely to get a fracture if she were to fall again. Alendronate prevents bone loss, and should be taken in addition to the calcium and vitamin D. MK should take alendronate in the morning with a full glass of water (~8 ounces) at least 30 minutes before eating, taking other medications, or drinking anything besides water, and should remain upright (either sitting or standing) for 30 minutes, not 2 hours. This is to prevent any esophageal damage that might result from direct contact of alendronate on the esophagus. MK also is taking lansoprazole, which may interact with the calcium. Calcium is better absorbed in an acidic stomach environment, but MK likely has reduced calcium absorption due to her lansoprazole-induced acid suppression. She might benefit by switching to a calcium citrate form (plus vitamin D), which does not require as much acidity in the stomach for absorption.