Updates in Antibiotic Therapy for Common Illnesses

71 Pages·2016·1.46 MB·English

by  Amy Brooks

UPDATES IN ANTIBIOTIC
THERAPY FOR COMMON
ILLNESSES
AMY BROOKS, PHARMD, BCPS
CLINICAL PHARMACIST
CONCORD HOSPITAL
CONCORD, NH
DISCLOSURES
I HAVE NO FINANCIAL RELATIONSHIPS TO DISCLOSE
I WILL BE DISCUSSING DOSING AND INDICATIONS OF
ANTIBIOTICS THAT MAY NOT BE FDA APPROVED
OBJECTIVES
• Explain basic pharmacology of major antibiotic drug classes
• Develop an understanding of why certain antibiotics are used for certain
disease states
• Discuss first-line antibiotic choices for common disease states
• Discuss circumstances in which alternative antibiotics would be necessary
BACKGROUND
• Studies have shown that up to 50% of all antibiotics
prescribed are inappropriate.1
• Leads to increased morbidity, mortality, cost, and bacterial
resistance1
• The spread of resistant bacteria can affect patients who
were not even exposed to the antibiotics.2
• The CDC estimates that more than 2 million people are
infected with antibiotic resistant bacteria yearly, leading to
approximately 23,000 deaths each year. 2
BACKGROUND
• 262.5 million antibiotics prescribed in the outpatient
setting each year3
• Outpatient prescribing practices affect local resistance
patterns3
• Prescribing practices vary by state and season3
• Azithromycin and amoxicillin are the most commonly
prescribed outpatient antibiotics3

ANTIBIOTIC DRUG CLASSES
• Penicillins
• Cephalosporins
• Carbapenems
• Fluoroquinolones
• Macrolides
• Clindamycin
• Glycopeptides (vancomycin)
• Daptomycin
• Linezolid
BASIC ANTIBIOTIC PRINCIPLES
• Dose matters (pharmacokinetics)
• The location of the infection in the body matters
(pharmacodynamics)
• Every bug has a drug
• There’s more to picking an antibiotic than “S” or “R”
• Much of antibiotic selection is risk vs benefit
• Weighing out the seriousness of the infection with the
seriousness of the antibiotic side effects
Β-LACTAMS4

• MOA: Inhibit cell wall
synthesis
• Bacteriocidal time-
dependant killing
• B-lactam ring is
responsible for
antibacterial activity, side
chains responsible for
spectrum of activity and
pharmacologic properties
B-LACTAMS4
• MOA: All β-lactams are cell wall active drugs that bind to penicillin-
binding proteins (PBPs) and inactivate them, which leads to cell death.
• Different bacteria have different types and varying amounts of PBPs
• β-lactam antibiotics have varying degrees of affinity for binding and
inactivating these different PBPs, which leads to differences in spectrum
of activity.
• Major side effects
• Hypersensitivity reactions (less common with newer agents)
• Myelosuppression, interstitial nephritis, serum sickness, seizures (rare)