ANTIBIOTIC SELECTION AND RESISTANCE: A

PHARMACIST’S PERSPECTIVEJennifer Ott, PharmD, BCPS

Clinical Pharmacy Specialist, Infectious DiseasesEastern Maine Medical Center

Bangor, MEjott@emh.org

The use of antibiotics is the single most important factor leading to antibiotic resistance

Up to 50% of all antibiotics prescribed are not needed or are not optimally effective as prescribed

CDC. Threat Report 2013. http://www.cdc.gov/drugresistance/threat-report-2013/

Increased Use of Vancomycin Associated with Resistance

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Kim NJ. JID 1999;179:163

N. gonorrhoeae Resistance in the United States 1987-2011

The Gonococcal Isolate Surveillance Project

Individuals prescribed an antibiotic in primary care for a respiratory or urinary infection develop resistance to that antibiotic Greatest effect in the month immediately

following treatment but may persist for up to 12 months

Costelloe, C. et al. BMJ 2010: 340:c2096.

Effect of Antibiotic Prescribing in Primary Care on Antimicrobial Resistance

Costelloe C et al. BMJ. 2010;340:c2096.

Nursing Home Patients Example

1 Centers for Medicare and Medicaid Services, Long Term Care Minimum Data Set, Resident profile table as of 05/02/2005. Baltimore. MD. 2 Loeb, M et.al. Antibiotic use in Ontario facilities that provide chronic care. J Gen Intern Med 2001; 16: 376-383. 3 Centers for Disease Control and Prevention, National Center for Health statistics, 1999 National Nursing Home Survey. Nursing Home Residents, number, percent distribution, and rate per 10,000, by age at interview, according to sex, race, and region: United States, 1999.

Acinetobacter Resistance to Imipenem

http://www.cdc.gov/getsmart/campaign-materials/week/images/resistance.png

Inappropriate Dosing May Lead to Resistance

Data pooled from 4 studies Gram-negative pneumonia Ciprofloxacin resistance associated with AUC/MIC

<100

Thomas JK, et al. Antimicrob Agents Chemother. 1998;42:521-527.

Dosing Matters – Penicillin Example

Penicillin half-life is only 30-45 minutes Retrospective review of Streptococcal

infective endocarditis Penicillin given every 4 hours was associated

with successful treatment vs every 6 hours (OR 2.79; 95%CI 1.43-5.62)

Sandoe JAT, et al. J Antimicrob Chemother. 2013; June 13 [Epub ahead of print]

Pseudomonas aeruginosa MIC Distribution

Dosing Optimization Example

Shea KM, et al. Ann Pharmacother 2009;43:1747-1754

Optimizing Dosing – Cefepime Example

Cefepime Tertiary references suggest a dose of 1-2 g q8-

12h Susceptibility breakpoints are based on 1 g

q8h (= 2g q12h) Meaning: using 1 g q12h for pneumonia does

not optimize the dosing of cefepime and risks undertreating the patient

Current Antibiotic Resistance Threat in the United States

CDC. Threat Report 2013. http://www.cdc.gov/drugresistance/threat-report-2013/

BAD BUGS, NO DRUGS

As Antibiotic Discovery Stagnates…A Public Health Crisis Brews

Boucher HW, et al. Clin Infect Dis 2009;48:1-12.

The AntibioticPipeline

http://www.rff.org/RFF/Documents/ETC-06.pdf Accessed Jan 1, 2013

Anti-infective Stewardship

Promotion of appropriate and responsible use of anti-infective agents Optimize anti-infective therapy

Drug Dose Route Duration

Patient tolerance and safety Limit preventable adverse events Drug-drug or drug-disease interactions

Questions

Are Antibiotics Really Benign?

CDC. Threat Report 2013. http://www.cdc.gov/drugresistance/threat-report-2013/

Infections with Resistant Organisms are on the Rise

Objectives

Antibiotic overuse promotes resistance Goal – use most narrow spectrum agent for

appropriate duration Increased resistant organisms are on the rise Inappropriate antibiotic dosing may promote

resistance Antibiotic pipeline is diminishing What to do

Promote appriopriate anti-infective use Use most narrow spectrum anti-infective agent at

optimal doses for the appropriate duration