Case Studies (November 2014)

November 12, 2014
Audrey R. Corman, BS

,
Craig I. Coleman

CASE 1

CU, a 52-year-old woman, presents to the clinic complaining of "cloudy urine." CU has a medical history significant for type 2 diabetes mellitus but it has been fairly well controlled in the past 3 months (glycated hemoglobin: 7.2). CU's urine dipstick is positive for white blood cells and bacteria, but CU denies having pain or tenderness, fever, urinary urgency, or dysuria. Her physician consults with you (the pharmacist) regarding antibiotic choice.

What would you recommend regarding CU's antibiotic?

CASE 2

JD is a 33-year-old man who comes to your pharmacy to refill his prescription for olanzapine 15 mg daily for schizophrenia. He mentions that he smokes a pack and a half (30 cigarettes) a day, but he would like to quit. He says his friend went to a smoking cessation clinic where they put him on nicotine patches, and they worked great. JD asks you, his pharmacist, "Would nicotine patches be a good way for me to quit as well?" He says his psychiatric condition has been very stable for the past year while he has taking olanzapine, and he does not want to "mess anything up."

What advice would you give to JD?

ANSWERS

Case 1: Based on the absence of symptoms but the presence of white blood cells (pyuria) and bacteria (≥105 colony forming units/mL) in CU’s urine, she appears to be suffering from asymptomatic bacteriuria. Asymptomatic bacteriuria is common in diabetic women, with an estimated prevalence rate of 9% to 27%. Asymptomatic bacteriuria is seldom associated with adverse outcomes, and treatment may be associated with undesirable outcomes, including antibiotic resistance, adverse drug reactions,and cost. For this reason, the Infectious Disease Society of America (IDSA) guidelines do not recommend screening for or treatment of asymptomatic bacteriuria in the following persons:

• Premenopausal, nonpregnant women (class A-I recommendation)

• Women with diabetes (A-I)

• Older persons living in the community (A-II)

• Elderly, institutionalized subjects (A-I) • Persons with spinal cord injury (A-II)

• Catheterized patients while the catheter remains in situ (A-I).

Based on the IDSA guidelines, you could recommend that CU not be treated with any antibiotic as long as she does not have or develop symptoms of a urinary tract infection or of pyelonephritis.

Case 2: Olanzapine is an atypical antipsychotic indicated for the treatment of schizophrenia. It is eliminated extensively by first-pass metabolism by CYP1A2 isoenzymes and through glucuronidation. While smoking induces CYP1A2 and has been shown to significantly alter the clearance of olanzapine, the nicotine patch has no effect on the CYP1A2 isoenzyme system, suggesting the pharmacokinetic interaction is not due to nicotine itself, but rather polycyclic aromatic hydrocarbons in cigarette smoke. Consequently, if JD attempts to stop smoking, regardless of pharmacologic or support group assistance, his serum levels of olanzapine may increase, putting him at greater risk for adverse effects, including orthostatic hypotension, dizziness, restlessness, and extrapyramidal symptoms such as akathisia, akinesia, and bradyphrenia. While you want to support JD’s desire to stop smoking, he should only attempt to do so under the careful supervision of his psychiatrist. The olanzapine dose may need to be reduced as JD’s cigarette use changes, often by as much as one-third over the first week of quitting.

Read the answers

Audrey R. Corman is a PharmD candidate at the University of Connecticut School of Pharmacy. Dr. Coleman is professor of pharmacy practice, as well as codirector and methods chief at Hartford Hospital Evidence-Based Practice Center, at the University of Connecticut School of Pharmacy.