Case Studies: Test Your Skills

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Pharmacy Times, August 2010 Oncology, Volume 76, Issue 8

Case One

Clostridium difficile Colitis

A pharmacist is rounding with the medical team in the intensive care unit. He meets QW, a 73-year-old man who has been treated with piperacillin/tazobactam and tobramycin for pneumonia for the past 6 days. His white blood cell count is elevated at 17,000 cells/μL, serum creatinine is 2.0 mg/dL, and he has developed diarrhea. He does not have hypotension, shock, ileus, or megacolon. The medical team suspects Clostridium difficile colitis. The attending physician wants to start metronidazole 500 mg 3 times daily, because this would be the patient’s first incident of C difficile. She cannot recall the new guidelines to treat C difficile colitis.

What should the pharmacist tell the medical team?

Case Two

Generalized Convulsive Status Epilepticus

RT is a 75-year-old woman who is brought to the emergency department. By the time she arrives, she has been experiencing continuous generalized rhythmic tonic-clonic seizure activity for more than 5 minutes. RT’s consciousness is impaired, but her daughter tells the medical team that RT does not have a history of seizures, but did have a stroke a few months back. The medical team diagnoses RT with generalized convulsive status epilepticus (GCSE).

Which medication would you recommend first to treat RT’s GCSE? What if your initial choice was ineffective?

ANSWERS

Case 1: According to the most recent practice guidelines for the treatment of C difficile infection, published in 2010 by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA), the initial agent of choice depends on the disease severity. The SHEA and IDSA recommend that for an initial episode of C difficile, metronidazole 500 mg by mouth 3 times daily for 10 to 14 days may be used in patients with mild-to-moderate disease (defined by the SHEA/IDSA as elevated white blood count, but <15,000 cells/μL and a serum creatinine <1.5 times the baseline level). For severe disease (defined as elevated white blood count >15,000 cells/ μL and a serum creatinine >1.5 times the baseline level), the SHEA and IDSA recommend the initial use of vancomycin 125 mg by mouth 4 times daily for 10 to 14 days. An initial episode is also considered to be severe and complicated if the patient exhibits hypotension, shock, ileus, or megacolon. In these cases, the recommended treatment is vancomycin 500 mg by mouth 4 times daily in addition to metronidazole 500 mg intravenously every 8 hours. Based on QW’s presentation, vancomycin 125 mg by mouth 4 times daily for 10 to 14 days would be an appropriate recommendation to the team.

Case 2: Benzodiazepines, in particular lorazepam (Ativan), are considered by most to be the first drug to be used in the treatment of GCSE. Lorazepam is administered as 4 mg intravenously (IV) at a rate of 2 mg per minute. An additional dose of 4 mg IV (at the same rate) can be administered if RT’s seizure continues or if it recurs after 10 to 15 minutes. If lorazepam fails to adequately control GCSE, phenytoin sodium is typically administered as second-line therapy. Third-line drugs for refractory status epilepticus (defined as failing to respond to both benzodiazepine and phenytoin therapies) often include phenobarbital, midazolam, propofol, pentobarbital, valproate, levetiracetam, or lidocaine.

Read the answers

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Dr. Coleman is an associate professor of pharmacy practice and director of the pharmacoeconomics and outcomes studies group at the University of Connecticut School of Pharmacy. Dr. Phung is assistant professor of pharmacy practice at University of Health Sciences College of Pharmacy, Pomona, California.