Case Studies

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Pharmacy Times, October 2012 Diabetes, Volume 79, Issue 10

Case One

DS is a 76-year-old normotensive woman who was diagnosed with osteoarthritis (OA) in her right hand. After trying acetaminophen 1 g 4 times daily with no relief, her physician suggested that she try naproxen 500 mg twice daily. At her 2-week follow-up visit, DS reports far less discomfort in her hand. but her blood pressure is now 142/84 mm Hg. The physician considers prescribing hydrochlorothiazide 12.5 mg once daily, but would like the input of a pharmacist first.

What recommendation should the pharmacist provide DS’s prescriber?

Case Two

DW is a 48-year-old woman who presents to the clinic with dysuria, frequent urination, and suprapubic tenderness. Her urine dipstick is positive for nitrite and leukocyte esterase. The physician diagnoses DW with an uncomplicated urinary tract infection (UTI) and prescribes levofloxacin 250 mg once daily for 3 days. The pharmacist working alongside the physician would like to assure DW that she is being treated according to available guideline recommendations. The pharmacist looks over local resistance patterns at their affiliated hospital and sees that Escherichia coli (the pathogen causing uncomplicated cystitis in 80%-85% of patients) has a low (<80%) susceptibility to trimethoprim/sulfamethoxazole (TMP/SMX).

What treatment recommendations, if any, should the pharmacist make to the prescribing physician?

ANSWERS

Case 1: Nonsteroidal anti-inflammatory drugs (NSAIDs) relieve OA pain by inhibiting cyclooxygenases responsible for converting arachadonic acid into inflammation-mediating prostaglandins. However, NSAIDs can also promote sodium and fluid retention, which can increase mean arterial blood pressure as much as 5 to 6 mm Hg. The temporal relationship between the diagnosis of hypertension in DS and the initiation of naproxen suggests that naproxen is the cause. Therefore,the pharmacist should suggest it be discontinued and that DS’s blood pressure be rechecked a week after stopping naproxen.

Current American College of Rheumatology OA guidelines recommend the use of topical NSAIDs, topical capsaicin, or oral NSAIDs including COX-2 selective inhibitors after failing acetaminophen at doses greater than or equal to 3 g/day. Because of increased risks for NSAID-induced hypertension and renal failure in patients 75 years and older, the guidelines favor the use of topical over oral NSAIDs. In addition, guidelines specifically recommend against the use of intra-articular therapies and opioid analgesics for OA of the hand. Because DS did receive benefit from an oral NSAID, 2 g of diclofenac 1% gel applied to the affected area 4 times daily might be considered a reasonable alternative.

Case 2: Antibiotic selection should be based on choosing a drug with the narrowest effective spectrum and the least side effects. Fluoroquiolones are highly effective for UTIs and some experts consider them to be first-line drugs for empiric therapy. However, recent Infectious Disease Society of America (IDSA) UTI guidelines discourage their use as first-line treatment because of the potential to cause resistance and the desire to reserve fluoroquinolones for more serious infectsions.

The IDSA guidelines for acute uncomplicated cystitis suggest using nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days, TMP/SMX 160/800 mg twice daily for 3 days, or a single 3-g dose of fosfomycin trometamol as first-line treatments of an uncomplicated UTI. For empirical TMP/SMX use, local resistances of uropathogens (E coli, Klebsiella spp, Proteus spp, and Staphylococcus saprophyticus) should be less than 20%. Fluoroquinolones should be considered only if the first-line medications cannot be used. The guidelines also recognize that the choice of antibiotic should be individualized based on patient allergy and adherence, availability, cost, and patient/provider threshold for failure.

Based upon the ISDA guidelines and the resistance patterns at DW's clinic, nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days is a good empiric option.

Read the answers

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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. Ms. Stern is a PharmD candidate from the University of Connecticut School of Pharmacy.