1. Antibiotics: Part I Penicillins Macrolides Tetracylines Glycyclines
Carbapenems

2. Antimicrobial Objectives Part I and Part II
Discuss the general principles of antibiotic therapy.
Explain how antibiotics work to rid the body of infection.
Discuss the pros and cons of antibiotic usage.
Describe the signs and symptoms, diagnostic criteria, and common treatment of the
superinfections: candidiasis and clostrium difficile colitis.
5. Discuss the MOA, indications, cautions, common and serious adverse reactions associated
with selected antibiotic groups:
Antibiotics Part I:
Penicillins
Macrolides
Tetracyclines/Glycyclines
Carbapenems
Antibiotics Part II:
Cephalosporins
Sulfonamides
Aminioglycosides
Fluroquinolones
Oxazolidinones
Lincosamides

3. Match the Drug to the Bug!!
Introduction to Antibiotics: Penicillins, Macrolides, Tetracyclines & Carbapenems
Match the Drug to the Bug!!

4. Glycyclines – newer and less resistant Carbapenems
Penicillins
(some are SENSITIVE to penicillinase producing bacteria and some are RESISTANT)
Macrolides
NARROW SPECTRUM
Gram (+) only
Tetracyclines
BROAD SPECTRUM, but many bacteria now resistant
Glycyclines – newer and less resistant
Carbapenems
*procaine penicillin (IM/IV)
erythromycin (EES) (po)
doxycycline (Vibramycin) (po)
meropenem (Merrem)
*penicillin V (PenVeeK) (po)
azithromycin (Zithromax) (po/IV)
minocycline (Minocin) (po)
*amoxicillin (Amoxil) (po)
tigecycline (Tygacil)
A derivative of minocycline = Glycycline
+amoxicillin + clavulanic acid (Augmentin) (po)
+dicloxacillin (Dynapen) (po)
+piperacillin + tazobactam (Zosyn) (IV)
carbenicillin
(Geopen) anti-pseudomonas (IV)
***penicillinase sensitive abx – Abx is rendered “INEFFECTIVE” by bacteria that secrete penicillinase
+ penicillinase resistant abx – Abx is “EFFECTIVE” against bacteria that secrete pencillinase

5. PENICILLINS Natural and synthetic
Penicillins are the most widely effective and extensively used antibiotics
Structural component is a BETA-LACTAM RING
The job of penicillin is to
DESTROY the bacterial cell
wall
It does this by attacking
the cell wall with its beta lactam
ring….. Aka the penicillin missile contains
a beta- lactam ring

6. Penicillin “missile” is its beta-lactam ring
Bacteria after penicillin “attack”

7. What are penicillinase/betalactamase enzymes?
Some bacteria ‘got smart’ and developed a defense
an ENZYME that DESTROYS the penicillin beta lactam ring
This “ANTI-MISSILE” aka the “ENZYME”– renders these bacteria RESISTANT to the penicillin
Betalactamase enzymes that act directly on penicillin are known as “PENICILLINASES”
Betalactamase enzymes that act on other antibiotic classes (cephalosporins) are known as “BETALACTAMASES”
The “anti-missile” of resistant bacteria:
penicillinase for penicillin
betalactamase for cephalosporins

8. Bacteria resisting an antibiotic
Superbugs in acute care
VRE (enterococci)
MRSA (staph aureus)
Acinentobacter

9. Penicillins: Side Effects All Classes
Allergic reactions including: urticaria, pruritus, and angioedema
Most are mild, but about 10% of allergic reactions are lifel-threatening
Treatment of acute allergic reaction includes: epinephrine, steroids, and antihistamines
Some cross-sensitivity between cephalosporins and penicillins exist - so may see allergy to both
Generally well tolerated with *GI effects (N-V-D) most common problem
Nursing alert: always check allergy before administering penicillin. When giving IM, observe patient closely for at least 30 minutes
Foods may decrease absorption
angioedema

10. Urticaric Rash Typical urticaric rash from penicillin allergy
Erythematous, maculopapular rash

11. What is the MOA of Natural Penicillins?
Inhibits cell wall synthesis (bacteriocidal) by interrupting the enzyme needed for bacterial cell division
Narrow spectrum
Natural penicillins are effective against mild to moderate infections (strep & staph)
However, bacteria that can produce PENICILLINASE render the natural penicillins INEFFECTIVE 
These bacteria are known as “penicillin resistant bacteria”
Natural penicillin was originally used to treat STAPH INFECTIONS
but by 1953, 80% of all hospital strains of staph aureus were penicillin-resistant = (MRSA)
Bacteria produce penicillinase making them resistant to natural penicillins

12. Natural Penicillins NARROW spectrum agents penicillinase SENSITIVE penicillins the PENICILLIN is destroyed by bacteria that produce penicillinase OR the BACTERIA are penicillin resistant
Natural Penicillins
*aqueous penicillin G (Bicillin) (P)
Destroyed by gastric acid so cannot be given po
short duration of action and very painful
procaine penicillin (P) longer duration
Milky color and less painful
*penicillin V (PenVeeK) (PO)
Penicillin Pearls:
Effective against mostly Gram (+) bacteria, some gram(-)
Derived from a mold or fungus
Look for “cillin” suffix
Injectable form given deep IM
Prescribed in “units”

13. AMINOPENICILLINS BROADER spectrum action but NOT penicillinase resistant
Have an amino group attached to their penicillin nucleus that makes them more effective against gram (-) bacteria
Also still effective against some gram (+) bacteria
Sensitive to penicillinase producing bacteria, so…. NOT effective against staph aureus (MRSA) which DO produce penicilinase
Therapeutic uses: treatment of sinusitis, otitis media, and bacterial endocarditis prophylaxis
Common drugs:
amoxicillin (Amoxil) (po)- most commonly Rx
Otitis media =
Ear infection
Frontal sinusitis

14. *dicloxacillin (Dynapen) (PO)
PENICILLINASE RESISTANT PENICILLINS Betalactam ABX that CAN destroy betalactamase sooo… EFFECTIVE against pencillinase/betalactamase producing bacteria
These agents ARE effective against gram + betalactamase/penicillinase producing bacteria
1/3 of all otitis media bacteria now produce penicillinase
Anti-staphlococcal penicillin= EFFECTIVE against infections caused by staph..MRSA
Commonly rx drugs
*dicloxacillin (Dynapen) (PO)
Therapeutic Uses: to treat serious infections: bone and joint, CNS, endocarditis, septicemia

15. Staph Aureus Infections
Methicillin resistant staph aureus (MRSA)
Bacteria that can cause SERIOUS infections.
These bacteria are RESISTANT to methicillin/penicillins
Rendering the penicillins ineffective
Causes wound infections, urinary tract infections, pneumonia, sepsis
Staph r/t illnessess
Mild to severe skin infections
Toxic shock syndrome
Food poisoning

16. MRSA Skin Infections

17. Penicillinase /betalactamase INHIBITORS
Combination of a broad spectrum penicillin (amoxicillin) WITH a beta-lactamase inhibitor (clavulanic acid)
Broader spectrum
Effective against gm (+), gm (-), anaerobes, AND betalactamase producing bacteria
Three betalactamase inhibitors
Clavulanic acid
Sulbactam
Tazobactam

18. Extended Spectrum Penicillins Beta-Lactamase Inhibitors
Oral: amoxicillin + clavulanic acid = Augumentin
Parenteral:
ampicillin + sulbactam = Unasyn
piperacillin + tazobactam = Zosyn
ticarcillin + clavulanic acid = Timentin
** Most beta-lactam abx are excreted via the kidneys. Important to assess renal function.

19. Penicillins: Newest Extended Spectrum Penicillin
Are important in treating SERIOUS GRAM (–) infections d/t Pseudomonas
However, NO coverage against bacteria that produce betalactamase
So not a good choice for staph MRSA infections
Often used in combination with aminoglycosides
Made by making a few changes in basic penicillin structure
Common drug;
*carbenicillin (Geopen) (IV, IM, po)

20. Penicllins: Summary Slide
3. BROAD spectrum
(gram + and gram –) penicillinase sensitive aminopenicillins
amoxicillin (Amoxil)
4. EXTENDED spectrum
gram (+) and gram (-) AND penicillinase resistant
amoxicillin + clauvalnic (Augmentin)
pipercillin + tazobactam (Zosyn)
5.Newest Extended Spectrum Antibiotic
anti-pseudomonas penicillin
Pseudomonas serious Gm (-)
carbenicillin (Geopen)
1. NARROW spectrum
(gram +) penicillinase SENSITIVE
Procaine Penicillin
PenVeeK
2. NARROW spectrum
(gram +) penicillinase RESISTANT  anti-staph penicillins
dicloxacillin (Dynapen)

21. What is Pseudomonas? Pseudomonas is a gram (-) bacterium
Newest extended spectrum: effective against gram (-); but NOT resistant to penicillinase producing bacteria
Causes serious infections in hospitalized patients:
Skin/surgical site
Blood
Pneumonia

22. Macrolides MOA: inhibit bacterial protein synthesis
Bacteriostatic at low concentrations
Bactriocidal at high concentrations
PO or IV use only. Too painful to give IM!
1st Macrolide was erythromycin, which is known for its bad taste and GI upset

23. Macrolides (cont) Therapeutic uses: Narrow spectrum
Mostly active against gram (+) organisms
Suitable replacement for penicillin in hypersensitive pts
* Used for “atypical” infections (chlamydia, mycoplasma, bacteria that commonly cause STDs and pneumonia
Used to treat H pylori , bacteria that causes peptic ulcers

24. Macrolides *GI distress the most common complaint. GI motility
Adverse Effects
*GI distress the most common complaint. GI motility
Superinfections
Hepatotoxicity
 effect of theophyllin, coumadin, and carbamazepine (anticonvulsant)
Oral agents have a bad taste and many trade names have been developed trying to make more acceptable

25. Macrolides *erythromycin (many trade names Newer macrolide
Common drugs
*erythromycin (many trade names
E-mycin, eryped, EES)
Newer macrolide
azithromycin (Zithromax)
Zithromax has  duration, can be given QD
Drug interactions:
E-mycin can INHIBIT the metabolism of many other drugs. (theophyllin, warfarin, seizure drugs)
Erythromycin is MR YUK!
Tastes bad and causes diarrhea

26. Tetracyclines MOA: inhibit bacterial protein synthesis –bacteriostatic
True “broad spectrum” antibiotics, however many bacteria have developed RESISTANCE
Effective against
Some Gram (+)
Some Gram (-)
Rickettsia
Mycoplasma
Chlamydia
H. pylori (stomach bacteria that causes peptic ulcer
MOA: inhibit bacterial protein synthesis –bacteriostatic
Distributed well in body – crosses the BBB so WILL reach CSF

27. TETRACYCLINES Chemically related group of 5 antibiotics
No milk with tetracyclines
TETRACYCLINES
Chemically related group of 5 antibiotics
Bind (chelate) to Calcium and Magnesium and metallic ions to form insoluble complexes
So co-administration with milk, antacids, or iron salts causes  absorption of antibiotic
Not usually given to children younger than 8 years of age d/t adverse effects!

28. Tetracyclines Therapeutic uses:
Do not give to children under 8 years
Therapeutic uses:
Drug of choice for chlamydia, rickettsia infections, Lyme disease, Rocky Mountain spotted fever
Often used to treat acne and serious skin infections
Many Adverse Effects!
GI irritation
Photosensitivity
Superinfections
Hepatoxicity
Renal toxicity
In children – discoloration of teeth, depression of bone growth
Known teratogenic drug
Blood dyscrasias

29. Tetracyclines Look for “cycline” suffix Interactions: Common drugs:
doxycycline – (Vibramycin) (P), (PO)
minocycline (Minocin) (PO)
Interactions:
absorption when given with milk, antacids, iron, or calcium

30. New Class: Glycylcline (2006)
MOA
a broad spectrum abx similar in structure to tetracycline
Is a derivative of minocycline
Blocks protein synthesis in bacterial cells  bacteriostatic

31. Glycycline tigecycline/Tygacil
ADVANTAGE: does not have resistant seen in older tetracyclines
BROAD SPECTRUM
IV use only for complicated skin and intra-abdominal infections
SE: similar to tetracyclines: photosensivity, GI upset, discoloration of teeth

32. Tygacil: for complicated skin and intra-abdominal infections
IV only!
Infected deep leg ulcer
Staph cellulitis

33. Carbapenem IV route only (phlebitis common) meropenem (Merrem)
ULTRA broad spectrum
IV route only (phlebitis common)
Used to treat serious mixed infections

34. Carbapenems Broadest spectrum of all Have a beta lactam structure
Must be given IV
Broadest spectrum of all
Used for complicated abdominal infections, meningitis
Well tolerated; with few adverse reactions
Can be used to treat “MIXED INFECTIONS”
Staph
Gm (-)
Gm (+)

35. That’s all Folks!!